v0.107.x stable

Follow-up of https://github.com/zed-industries/zed/pull/3059 

Before: 

![image](https://github.com/zed-industries/zed/assets/2690773/4eb2d2d1-1aa3-40b8-b782-bf2bc5f17b43)

After:

![image](https://github.com/zed-industries/zed/assets/2690773/5587d46b-9198-45fe-9372-114a95d4b7d6)

Release Notes:

- N/A

.github/workflows/release_actions.yml

@@ -6,8 +6,8 @@ jobs:
   discord_release:
     runs-on: ubuntu-latest
     steps:
-    - name: Get appropriate URL
-      id: get-appropriate-url
+    - name: Get release URL
+      id: get-release-url
       run: |
         if [ "${{ github.event.release.prerelease }}" == "true" ]; then
           URL="https://zed.dev/releases/preview/latest"
@@ -15,14 +15,19 @@ jobs:
           URL="https://zed.dev/releases/stable/latest"
         fi
         echo "::set-output name=URL::$URL"
+    - name: Get content
+      uses: 2428392/gh-truncate-string-action@v1.2.0
+      id: get-content
+      with:
+        stringToTruncate: |
+          📣 Zed ${{ github.event.release.tag_name }} was just released!
 
+          Restart your Zed or head to ${{ steps.get-release-url.outputs.URL }} to grab it.
+
+          ${{ github.event.release.body }}
+        maxLength: 2000
     - name: Discord Webhook Action
       uses: tsickert/discord-webhook@v5.3.0
       with:
         webhook-url: ${{ secrets.DISCORD_WEBHOOK_URL }}
-        content: |
-          📣 Zed ${{ github.event.release.tag_name }} was just released!
-
-          Restart your Zed or head to ${{ steps.get-appropriate-url.outputs.URL }} to grab it.
-
-          ${{ github.event.release.body }}
+        content: ${{ steps.get-content.outputs.string }}

Cargo.toml

@@ -2,6 +2,7 @@
 members = [
     "crates/activity_indicator",
     "crates/ai",
+    "crates/assistant",
     "crates/audio",
     "crates/auto_update",
     "crates/breadcrumbs",
@@ -63,12 +64,14 @@ members = [
     "crates/sqlez",
     "crates/sqlez_macros",
     "crates/feature_flags",
+    "crates/rich_text",
     "crates/storybook",
     "crates/sum_tree",
     "crates/terminal",
     "crates/text",
     "crates/theme",
     "crates/theme_selector",
+    "crates/ui",
     "crates/util",
     "crates/semantic_index",
     "crates/vim",
@@ -103,12 +106,14 @@ rand = { version = "0.8.5" }
 refineable = { path = "./crates/refineable" }
 regex = { version = "1.5" }
 rust-embed = { version = "8.0", features = ["include-exclude"] }
+rusqlite = { version = "0.29.0", features = ["blob", "array", "modern_sqlite"] }
 schemars = { version = "0.8" }
 serde = { version = "1.0", features = ["derive", "rc"] }
 serde_derive = { version = "1.0", features = ["deserialize_in_place"] }
 serde_json = { version = "1.0", features = ["preserve_order", "raw_value"] }
 smallvec = { version = "1.6", features = ["union"] }
 smol = { version = "1.2" }
+sysinfo = "0.29.10"
 tempdir = { version = "0.3.7" }
 thiserror = { version = "1.0.29" }
 time = { version = "0.3", features = ["serde", "serde-well-known"] }
@@ -117,6 +122,7 @@ tree-sitter = "0.20"
 unindent = { version = "0.1.7" }
 pretty_assertions = "1.3.0"
 git2 = { version = "0.15", default-features = false}
+uuid = { version = "1.1.2", features = ["v4"] }
 
 tree-sitter-bash = { git = "https://github.com/tree-sitter/tree-sitter-bash", rev = "1b0321ee85701d5036c334a6f04761cdc672e64c" }
 tree-sitter-c = "0.20.1"

Procfile

@@ -1,4 +1,4 @@
-web: cd ../zed.dev && PORT=3000 npx vercel dev
-collab: cd crates/collab && cargo run serve
+web: cd ../zed.dev && PORT=3000 npm run dev
+collab: cd crates/collab && RUST_LOG=${RUST_LOG:-collab=info} cargo run serve
 livekit: livekit-server --dev
 postgrest: postgrest crates/collab/admin_api.conf

README.md

@@ -13,7 +13,7 @@ Welcome to Zed, a lightning-fast, collaborative code editor that makes your drea
   sudo xcodebuild -license
   ```
 
-* Install homebrew, node and rustup-init (rutup, rust, cargo, etc.)
+* Install homebrew, node and rustup-init (rustup, rust, cargo, etc.)
   ```
   /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
   brew install node rustup-init
@@ -36,7 +36,7 @@ Welcome to Zed, a lightning-fast, collaborative code editor that makes your drea
     brew install foreman
     ```
 
-* Ensure the Zed.dev website is checked out in a sibling directory and install it's dependencies:
+* Ensure the Zed.dev website is checked out in a sibling directory and install its dependencies:
 
     ```
     cd ..

assets/keymaps/default.json

@@ -30,6 +30,7 @@
       "cmd-s": "workspace::Save",
       "cmd-shift-s": "workspace::SaveAs",
       "cmd-=": "zed::IncreaseBufferFontSize",
+      "cmd-+": "zed::IncreaseBufferFontSize",
       "cmd--": "zed::DecreaseBufferFontSize",
       "cmd-0": "zed::ResetBufferFontSize",
       "cmd-,": "zed::OpenSettings",
@@ -249,6 +250,7 @@
     "bindings": {
       "escape": "project_search::ToggleFocus",
       "alt-tab": "search::CycleMode",
+      "cmd-shift-h": "search::ToggleReplace",
       "alt-cmd-g": "search::ActivateRegexMode",
       "alt-cmd-s": "search::ActivateSemanticMode",
       "alt-cmd-x": "search::ActivateTextMode"
@@ -261,11 +263,19 @@
       "down": "search::NextHistoryQuery"
     }
   },
+  {
+    "context": "ProjectSearchBar && in_replace",
+    "bindings": {
+      "enter": "search::ReplaceNext",
+      "cmd-enter": "search::ReplaceAll"
+    }
+  },
   {
     "context": "ProjectSearchView",
     "bindings": {
       "escape": "project_search::ToggleFocus",
       "alt-tab": "search::CycleMode",
+      "cmd-shift-h": "search::ToggleReplace",
       "alt-cmd-g": "search::ActivateRegexMode",
       "alt-cmd-s": "search::ActivateSemanticMode",
       "alt-cmd-x": "search::ActivateTextMode"
@@ -277,6 +287,7 @@
       "cmd-f": "project_search::ToggleFocus",
       "cmd-g": "search::SelectNextMatch",
       "cmd-shift-g": "search::SelectPrevMatch",
+      "cmd-shift-h": "search::ToggleReplace",
       "alt-enter": "search::SelectAllMatches",
       "alt-cmd-c": "search::ToggleCaseSensitive",
       "alt-cmd-w": "search::ToggleWholeWord",
@@ -498,6 +509,22 @@
       "cmd-k cmd-down": [
         "workspace::ActivatePaneInDirection",
         "Down"
+      ],
+      "cmd-k shift-left": [
+        "workspace::SwapPaneInDirection",
+        "Left"
+      ],
+      "cmd-k shift-right": [
+        "workspace::SwapPaneInDirection",
+        "Right"
+      ],
+      "cmd-k shift-up": [
+        "workspace::SwapPaneInDirection",
+        "Up"
+      ],
+      "cmd-k shift-down": [
+        "workspace::SwapPaneInDirection",
+        "Down"
       ]
     }
   },
@@ -562,7 +589,7 @@
     }
   },
   {
-    "context": "ProjectSearchBar",
+    "context": "ProjectSearchBar && !in_replace",
     "bindings": {
       "cmd-enter": "project_search::SearchInNew"
     }
@@ -588,14 +615,20 @@
     }
   },
   {
-    "context": "CollabPanel",
+    "context": "CollabPanel && not_editing",
     "bindings": {
       "ctrl-backspace": "collab_panel::Remove",
       "space": "menu::Confirm"
     }
   },
   {
-    "context": "CollabPanel > Editor",
+    "context": "(CollabPanel && editing) > Editor",
+    "bindings": {
+      "space": "collab_panel::InsertSpace"
+    }
+  },
+  {
+    "context": "(CollabPanel && not_editing) > Editor",
     "bindings": {
       "cmd-c": "collab_panel::StartLinkChannel",
       "cmd-x": "collab_panel::StartMoveChannel",

assets/keymaps/vim.json

@@ -18,6 +18,7 @@
           }
         }
       ],
+      ":": "command_palette::Toggle",
       "h": "vim::Left",
       "left": "vim::Left",
       "backspace": "vim::Backspace",
@@ -94,6 +95,7 @@
         }
       ],
       "ctrl-o": "pane::GoBack",
+      "ctrl-i": "pane::GoForward",
       "ctrl-]": "editor::GoToDefinition",
       "escape": [
         "vim::SwitchMode",
@@ -125,10 +127,26 @@
       "g shift-t": "pane::ActivatePrevItem",
       "g d": "editor::GoToDefinition",
       "g shift-d": "editor::GoToTypeDefinition",
+      "g n": "vim::SelectNext",
+      "g shift-n": "vim::SelectPrevious",
+      "g >": [
+        "editor::SelectNext",
+        {
+          "replace_newest": true
+        }
+      ],
+      "g <": [
+        "editor::SelectPrevious",
+        {
+          "replace_newest": true
+        }
+      ],
+      "g a": "editor::SelectAllMatches",
       "g s": "outline::Toggle",
       "g shift-s": "project_symbols::Toggle",
       "g .": "editor::ToggleCodeActions", // zed specific
       "g shift-a": "editor::FindAllReferences", // zed specific
+      "g space": "editor::OpenExcerpts", // zed specific
       "g *": [
         "vim::MoveToNext",
         {
@@ -205,13 +223,13 @@
       "shift-z shift-q": [
         "pane::CloseActiveItem",
         {
-          "saveBehavior": "dontSave"
+          "saveIntent": "skip"
         }
       ],
       "shift-z shift-z": [
         "pane::CloseActiveItem",
         {
-          "saveBehavior": "promptOnConflict"
+          "saveIntent": "saveAll"
         }
       ],
       // Count support
@@ -300,6 +318,38 @@
         "workspace::ActivatePaneInDirection",
         "Down"
       ],
+      "ctrl-w shift-left": [
+        "workspace::SwapPaneInDirection",
+        "Left"
+      ],
+      "ctrl-w shift-right": [
+        "workspace::SwapPaneInDirection",
+        "Right"
+      ],
+      "ctrl-w shift-up": [
+        "workspace::SwapPaneInDirection",
+        "Up"
+      ],
+      "ctrl-w shift-down": [
+        "workspace::SwapPaneInDirection",
+        "Down"
+      ],
+      "ctrl-w shift-h": [
+        "workspace::SwapPaneInDirection",
+        "Left"
+      ],
+      "ctrl-w shift-l": [
+        "workspace::SwapPaneInDirection",
+        "Right"
+      ],
+      "ctrl-w shift-k": [
+        "workspace::SwapPaneInDirection",
+        "Up"
+      ],
+      "ctrl-w shift-j": [
+        "workspace::SwapPaneInDirection",
+        "Down"
+      ],
       "ctrl-w g t": "pane::ActivateNextItem",
       "ctrl-w ctrl-g t": "pane::ActivateNextItem",
       "ctrl-w g shift-t": "pane::ActivatePrevItem",
@@ -318,7 +368,17 @@
       "ctrl-w c": "pane::CloseAllItems",
       "ctrl-w ctrl-c": "pane::CloseAllItems",
       "ctrl-w q": "pane::CloseAllItems",
-      "ctrl-w ctrl-q": "pane::CloseAllItems"
+      "ctrl-w ctrl-q": "pane::CloseAllItems",
+      "ctrl-w o": "workspace::CloseInactiveTabsAndPanes",
+      "ctrl-w ctrl-o": "workspace::CloseInactiveTabsAndPanes",
+      "ctrl-w n": [
+        "workspace::NewFileInDirection",
+        "Up"
+      ],
+      "ctrl-w ctrl-n": [
+        "workspace::NewFileInDirection",
+        "Up"
+      ]
     }
   },
   {
@@ -357,6 +417,8 @@
       "o": "vim::InsertLineBelow",
       "shift-o": "vim::InsertLineAbove",
       "~": "vim::ChangeCase",
+      "ctrl-a": "vim::Increment",
+      "ctrl-x": "vim::Decrement",
       "p": "vim::Paste",
       "shift-p": [
         "vim::Paste",
@@ -468,6 +530,20 @@
       "shift-r": "vim::SubstituteLine",
       "c": "vim::Substitute",
       "~": "vim::ChangeCase",
+      "ctrl-a": "vim::Increment",
+      "ctrl-x": "vim::Decrement",
+      "g ctrl-a": [
+        "vim::Increment",
+        {
+          "step": true
+        }
+      ],
+      "g ctrl-x": [
+        "vim::Decrement",
+        {
+          "step": true
+        }
+      ],
       "shift-i": "vim::InsertBefore",
       "shift-a": "vim::InsertAfter",
       "shift-j": "vim::JoinLines",
@@ -508,11 +584,16 @@
     }
   },
   {
-    "context": "Editor && vim_mode == insert && !menu",
+    "context": "Editor && vim_mode == insert",
     "bindings": {
       "escape": "vim::NormalBefore",
       "ctrl-c": "vim::NormalBefore",
-      "ctrl-[": "vim::NormalBefore"
+      "ctrl-[": "vim::NormalBefore",
+      "ctrl-x ctrl-o": "editor::ShowCompletions",
+      "ctrl-x ctrl-a": "assistant::InlineAssist", // zed specific
+      "ctrl-x ctrl-c": "copilot::Suggest", // zed specific
+      "ctrl-x ctrl-l": "editor::ToggleCodeActions", // zed specific
+      "ctrl-x ctrl-z": "editor::Cancel"
     }
   },
   {
@@ -531,7 +612,7 @@
     }
   },
   {
-    "context": "BufferSearchBar > VimEnabled",
+    "context": "BufferSearchBar && !in_replace > VimEnabled",
     "bindings": {
       "enter": "vim::SearchSubmit",
       "escape": "buffer_search::Dismiss"

assets/settings/default.json

@@ -227,6 +227,11 @@
   },
   // Automatically update Zed
   "auto_update": true,
+  // Diagnostics configuration.
+  "diagnostics": {
+    // Whether to show warnings or not by default.
+    "include_warnings": true
+  },
   // Git gutter behavior configuration.
   "git": {
     // Control whether the git gutter is shown. May take 2 values:
@@ -356,7 +361,7 @@
           ".venv",
           "venv"
         ],
-        // Can also be 'csh' and 'fish'
+        // Can also be 'csh', 'fish', and `nushell`
         "activate_script": "default"
       }
     }
@@ -370,7 +375,28 @@
   },
   // Difference settings for semantic_index
   "semantic_index": {
-    "enabled": false
+    "enabled": true
+  },
+  // Settings specific to our elixir integration
+  "elixir": {
+    // Change the LSP zed uses for elixir.
+    // Note that changing this setting requires a restart of Zed
+    // to take effect.
+    //
+    // May take 3 values:
+    //  1. Use the standard ElixirLS, this is the default
+    //         "lsp": "elixir_ls"
+    //  2. Use the experimental NextLs
+    //         "lsp": "next_ls",
+    //  3. Use a language server installed locally on your machine:
+    //         "lsp": {
+    //           "local": {
+    //             "path": "~/next-ls/bin/start",
+    //             "arguments": ["--stdio"]
+    //            }
+    //          },
+    //
+    "lsp": "elixir_ls"
   },
   // Different settings for specific languages.
   "languages": {

crates/ai/Cargo.toml

@@ -9,39 +9,26 @@ path = "src/ai.rs"
 doctest = false
 
 [dependencies]
-client = { path = "../client" }
-collections = { path = "../collections"}
-editor = { path = "../editor" }
-fs = { path = "../fs" }
 gpui = { path = "../gpui" }
-language = { path = "../language" }
-menu = { path = "../menu" }
-search = { path = "../search" }
-settings = { path = "../settings" }
-theme = { path = "../theme" }
 util = { path = "../util" }
-uuid = { version = "1.1.2", features = ["v4"] }
-workspace = { path = "../workspace" }
-
+async-trait.workspace = true
 anyhow.workspace = true
-chrono = { version = "0.4", features = ["serde"] }
 futures.workspace = true
-indoc.workspace = true
-isahc.workspace = true
+lazy_static.workspace = true
 ordered-float.workspace = true
 parking_lot.workspace = true
+isahc.workspace = true
 regex.workspace = true
-schemars.workspace = true
 serde.workspace = true
 serde_json.workspace = true
-smol.workspace = true
-tiktoken-rs = "0.4"
+postage.workspace = true
+rand.workspace = true
+log.workspace = true
+parse_duration = "2.1.1"
+tiktoken-rs = "0.5.0"
+matrixmultiply = "0.3.7"
+rusqlite = { version = "0.29.0", features = ["blob", "array", "modern_sqlite"] }
+bincode = "1.3.3"
 
 [dev-dependencies]
-editor = { path = "../editor", features = ["test-support"] }
-project = { path = "../project", features = ["test-support"] }
-
-ctor.workspace = true
-env_logger.workspace = true
-log.workspace = true
-rand.workspace = true
+gpui = { path = "../gpui", features = ["test-support"] }

crates/ai/src/ai.rs

@@ -1,294 +1,2 @@
-pub mod assistant;
-mod assistant_settings;
-mod codegen;
-mod streaming_diff;
-
-use anyhow::{anyhow, Result};
-pub use assistant::AssistantPanel;
-use assistant_settings::OpenAIModel;
-use chrono::{DateTime, Local};
-use collections::HashMap;
-use fs::Fs;
-use futures::{io::BufReader, AsyncBufReadExt, AsyncReadExt, Stream, StreamExt};
-use gpui::{executor::Background, AppContext};
-use isahc::{http::StatusCode, Request, RequestExt};
-use regex::Regex;
-use serde::{Deserialize, Serialize};
-use std::{
-    cmp::Reverse,
-    ffi::OsStr,
-    fmt::{self, Display},
-    io,
-    path::PathBuf,
-    sync::Arc,
-};
-use util::paths::CONVERSATIONS_DIR;
-
-const OPENAI_API_URL: &'static str = "https://api.openai.com/v1";
-
-// Data types for chat completion requests
-#[derive(Debug, Default, Serialize)]
-pub struct OpenAIRequest {
-    model: String,
-    messages: Vec<RequestMessage>,
-    stream: bool,
-}
-
-#[derive(
-    Copy, Clone, Debug, Default, Eq, PartialEq, PartialOrd, Ord, Hash, Serialize, Deserialize,
-)]
-struct MessageId(usize);
-
-#[derive(Clone, Debug, Serialize, Deserialize)]
-struct MessageMetadata {
-    role: Role,
-    sent_at: DateTime<Local>,
-    status: MessageStatus,
-}
-
-#[derive(Clone, Debug, Serialize, Deserialize)]
-enum MessageStatus {
-    Pending,
-    Done,
-    Error(Arc<str>),
-}
-
-#[derive(Serialize, Deserialize)]
-struct SavedMessage {
-    id: MessageId,
-    start: usize,
-}
-
-#[derive(Serialize, Deserialize)]
-struct SavedConversation {
-    id: Option<String>,
-    zed: String,
-    version: String,
-    text: String,
-    messages: Vec<SavedMessage>,
-    message_metadata: HashMap<MessageId, MessageMetadata>,
-    summary: String,
-    model: OpenAIModel,
-}
-
-impl SavedConversation {
-    const VERSION: &'static str = "0.1.0";
-}
-
-struct SavedConversationMetadata {
-    title: String,
-    path: PathBuf,
-    mtime: chrono::DateTime<chrono::Local>,
-}
-
-impl SavedConversationMetadata {
-    pub async fn list(fs: Arc<dyn Fs>) -> Result<Vec<Self>> {
-        fs.create_dir(&CONVERSATIONS_DIR).await?;
-
-        let mut paths = fs.read_dir(&CONVERSATIONS_DIR).await?;
-        let mut conversations = Vec::<SavedConversationMetadata>::new();
-        while let Some(path) = paths.next().await {
-            let path = path?;
-            if path.extension() != Some(OsStr::new("json")) {
-                continue;
-            }
-
-            let pattern = r" - \d+.zed.json$";
-            let re = Regex::new(pattern).unwrap();
-
-            let metadata = fs.metadata(&path).await?;
-            if let Some((file_name, metadata)) = path
-                .file_name()
-                .and_then(|name| name.to_str())
-                .zip(metadata)
-            {
-                let title = re.replace(file_name, "");
-                conversations.push(Self {
-                    title: title.into_owned(),
-                    path,
-                    mtime: metadata.mtime.into(),
-                });
-            }
-        }
-        conversations.sort_unstable_by_key(|conversation| Reverse(conversation.mtime));
-
-        Ok(conversations)
-    }
-}
-
-#[derive(Serialize, Deserialize, Debug, Eq, PartialEq)]
-struct RequestMessage {
-    role: Role,
-    content: String,
-}
-
-#[derive(Serialize, Deserialize, Debug, Eq, PartialEq)]
-pub struct ResponseMessage {
-    role: Option<Role>,
-    content: Option<String>,
-}
-
-#[derive(Clone, Copy, Serialize, Deserialize, Debug, Eq, PartialEq)]
-#[serde(rename_all = "lowercase")]
-enum Role {
-    User,
-    Assistant,
-    System,
-}
-
-impl Role {
-    pub fn cycle(&mut self) {
-        *self = match self {
-            Role::User => Role::Assistant,
-            Role::Assistant => Role::System,
-            Role::System => Role::User,
-        }
-    }
-}
-
-impl Display for Role {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> std::fmt::Result {
-        match self {
-            Role::User => write!(f, "User"),
-            Role::Assistant => write!(f, "Assistant"),
-            Role::System => write!(f, "System"),
-        }
-    }
-}
-
-#[derive(Deserialize, Debug)]
-pub struct OpenAIResponseStreamEvent {
-    pub id: Option<String>,
-    pub object: String,
-    pub created: u32,
-    pub model: String,
-    pub choices: Vec<ChatChoiceDelta>,
-    pub usage: Option<Usage>,
-}
-
-#[derive(Deserialize, Debug)]
-pub struct Usage {
-    pub prompt_tokens: u32,
-    pub completion_tokens: u32,
-    pub total_tokens: u32,
-}
-
-#[derive(Deserialize, Debug)]
-pub struct ChatChoiceDelta {
-    pub index: u32,
-    pub delta: ResponseMessage,
-    pub finish_reason: Option<String>,
-}
-
-#[derive(Deserialize, Debug)]
-struct OpenAIUsage {
-    prompt_tokens: u64,
-    completion_tokens: u64,
-    total_tokens: u64,
-}
-
-#[derive(Deserialize, Debug)]
-struct OpenAIChoice {
-    text: String,
-    index: u32,
-    logprobs: Option<serde_json::Value>,
-    finish_reason: Option<String>,
-}
-
-pub fn init(cx: &mut AppContext) {
-    assistant::init(cx);
-}
-
-pub async fn stream_completion(
-    api_key: String,
-    executor: Arc<Background>,
-    mut request: OpenAIRequest,
-) -> Result<impl Stream<Item = Result<OpenAIResponseStreamEvent>>> {
-    request.stream = true;
-
-    let (tx, rx) = futures::channel::mpsc::unbounded::<Result<OpenAIResponseStreamEvent>>();
-
-    let json_data = serde_json::to_string(&request)?;
-    let mut response = Request::post(format!("{OPENAI_API_URL}/chat/completions"))
-        .header("Content-Type", "application/json")
-        .header("Authorization", format!("Bearer {}", api_key))
-        .body(json_data)?
-        .send_async()
-        .await?;
-
-    let status = response.status();
-    if status == StatusCode::OK {
-        executor
-            .spawn(async move {
-                let mut lines = BufReader::new(response.body_mut()).lines();
-
-                fn parse_line(
-                    line: Result<String, io::Error>,
-                ) -> Result<Option<OpenAIResponseStreamEvent>> {
-                    if let Some(data) = line?.strip_prefix("data: ") {
-                        let event = serde_json::from_str(&data)?;
-                        Ok(Some(event))
-                    } else {
-                        Ok(None)
-                    }
-                }
-
-                while let Some(line) = lines.next().await {
-                    if let Some(event) = parse_line(line).transpose() {
-                        let done = event.as_ref().map_or(false, |event| {
-                            event
-                                .choices
-                                .last()
-                                .map_or(false, |choice| choice.finish_reason.is_some())
-                        });
-                        if tx.unbounded_send(event).is_err() {
-                            break;
-                        }
-
-                        if done {
-                            break;
-                        }
-                    }
-                }
-
-                anyhow::Ok(())
-            })
-            .detach();
-
-        Ok(rx)
-    } else {
-        let mut body = String::new();
-        response.body_mut().read_to_string(&mut body).await?;
-
-        #[derive(Deserialize)]
-        struct OpenAIResponse {
-            error: OpenAIError,
-        }
-
-        #[derive(Deserialize)]
-        struct OpenAIError {
-            message: String,
-        }
-
-        match serde_json::from_str::<OpenAIResponse>(&body) {
-            Ok(response) if !response.error.message.is_empty() => Err(anyhow!(
-                "Failed to connect to OpenAI API: {}",
-                response.error.message,
-            )),
-
-            _ => Err(anyhow!(
-                "Failed to connect to OpenAI API: {} {}",
-                response.status(),
-                body,
-            )),
-        }
-    }
-}
-
-#[cfg(test)]
-#[ctor::ctor]
-fn init_logger() {
-    if std::env::var("RUST_LOG").is_ok() {
-        env_logger::init();
-    }
-}
+pub mod completion;
+pub mod embedding;

crates/ai/src/completion.rs

@@ -0,0 +1,212 @@
+use anyhow::{anyhow, Result};
+use futures::{
+    future::BoxFuture, io::BufReader, stream::BoxStream, AsyncBufReadExt, AsyncReadExt, FutureExt,
+    Stream, StreamExt,
+};
+use gpui::executor::Background;
+use isahc::{http::StatusCode, Request, RequestExt};
+use serde::{Deserialize, Serialize};
+use std::{
+    fmt::{self, Display},
+    io,
+    sync::Arc,
+};
+
+pub const OPENAI_API_URL: &'static str = "https://api.openai.com/v1";
+
+#[derive(Clone, Copy, Serialize, Deserialize, Debug, Eq, PartialEq)]
+#[serde(rename_all = "lowercase")]
+pub enum Role {
+    User,
+    Assistant,
+    System,
+}
+
+impl Role {
+    pub fn cycle(&mut self) {
+        *self = match self {
+            Role::User => Role::Assistant,
+            Role::Assistant => Role::System,
+            Role::System => Role::User,
+        }
+    }
+}
+
+impl Display for Role {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Role::User => write!(f, "User"),
+            Role::Assistant => write!(f, "Assistant"),
+            Role::System => write!(f, "System"),
+        }
+    }
+}
+
+#[derive(Serialize, Deserialize, Debug, Eq, PartialEq)]
+pub struct RequestMessage {
+    pub role: Role,
+    pub content: String,
+}
+
+#[derive(Debug, Default, Serialize)]
+pub struct OpenAIRequest {
+    pub model: String,
+    pub messages: Vec<RequestMessage>,
+    pub stream: bool,
+}
+
+#[derive(Serialize, Deserialize, Debug, Eq, PartialEq)]
+pub struct ResponseMessage {
+    pub role: Option<Role>,
+    pub content: Option<String>,
+}
+
+#[derive(Deserialize, Debug)]
+pub struct OpenAIUsage {
+    pub prompt_tokens: u32,
+    pub completion_tokens: u32,
+    pub total_tokens: u32,
+}
+
+#[derive(Deserialize, Debug)]
+pub struct ChatChoiceDelta {
+    pub index: u32,
+    pub delta: ResponseMessage,
+    pub finish_reason: Option<String>,
+}
+
+#[derive(Deserialize, Debug)]
+pub struct OpenAIResponseStreamEvent {
+    pub id: Option<String>,
+    pub object: String,
+    pub created: u32,
+    pub model: String,
+    pub choices: Vec<ChatChoiceDelta>,
+    pub usage: Option<OpenAIUsage>,
+}
+
+pub async fn stream_completion(
+    api_key: String,
+    executor: Arc<Background>,
+    mut request: OpenAIRequest,
+) -> Result<impl Stream<Item = Result<OpenAIResponseStreamEvent>>> {
+    request.stream = true;
+
+    let (tx, rx) = futures::channel::mpsc::unbounded::<Result<OpenAIResponseStreamEvent>>();
+
+    let json_data = serde_json::to_string(&request)?;
+    let mut response = Request::post(format!("{OPENAI_API_URL}/chat/completions"))
+        .header("Content-Type", "application/json")
+        .header("Authorization", format!("Bearer {}", api_key))
+        .body(json_data)?
+        .send_async()
+        .await?;
+
+    let status = response.status();
+    if status == StatusCode::OK {
+        executor
+            .spawn(async move {
+                let mut lines = BufReader::new(response.body_mut()).lines();
+
+                fn parse_line(
+                    line: Result<String, io::Error>,
+                ) -> Result<Option<OpenAIResponseStreamEvent>> {
+                    if let Some(data) = line?.strip_prefix("data: ") {
+                        let event = serde_json::from_str(&data)?;
+                        Ok(Some(event))
+                    } else {
+                        Ok(None)
+                    }
+                }
+
+                while let Some(line) = lines.next().await {
+                    if let Some(event) = parse_line(line).transpose() {
+                        let done = event.as_ref().map_or(false, |event| {
+                            event
+                                .choices
+                                .last()
+                                .map_or(false, |choice| choice.finish_reason.is_some())
+                        });
+                        if tx.unbounded_send(event).is_err() {
+                            break;
+                        }
+
+                        if done {
+                            break;
+                        }
+                    }
+                }
+
+                anyhow::Ok(())
+            })
+            .detach();
+
+        Ok(rx)
+    } else {
+        let mut body = String::new();
+        response.body_mut().read_to_string(&mut body).await?;
+
+        #[derive(Deserialize)]
+        struct OpenAIResponse {
+            error: OpenAIError,
+        }
+
+        #[derive(Deserialize)]
+        struct OpenAIError {
+            message: String,
+        }
+
+        match serde_json::from_str::<OpenAIResponse>(&body) {
+            Ok(response) if !response.error.message.is_empty() => Err(anyhow!(
+                "Failed to connect to OpenAI API: {}",
+                response.error.message,
+            )),
+
+            _ => Err(anyhow!(
+                "Failed to connect to OpenAI API: {} {}",
+                response.status(),
+                body,
+            )),
+        }
+    }
+}
+
+pub trait CompletionProvider {
+    fn complete(
+        &self,
+        prompt: OpenAIRequest,
+    ) -> BoxFuture<'static, Result<BoxStream<'static, Result<String>>>>;
+}
+
+pub struct OpenAICompletionProvider {
+    api_key: String,
+    executor: Arc<Background>,
+}
+
+impl OpenAICompletionProvider {
+    pub fn new(api_key: String, executor: Arc<Background>) -> Self {
+        Self { api_key, executor }
+    }
+}
+
+impl CompletionProvider for OpenAICompletionProvider {
+    fn complete(
+        &self,
+        prompt: OpenAIRequest,
+    ) -> BoxFuture<'static, Result<BoxStream<'static, Result<String>>>> {
+        let request = stream_completion(self.api_key.clone(), self.executor.clone(), prompt);
+        async move {
+            let response = request.await?;
+            let stream = response
+                .filter_map(|response| async move {
+                    match response {
+                        Ok(mut response) => Some(Ok(response.choices.pop()?.delta.content?)),
+                        Err(error) => Some(Err(error)),
+                    }
+                })
+                .boxed();
+            Ok(stream)
+        }
+        .boxed()
+    }
+}

crates/ai/src/embedding.rs

@@ -27,8 +27,30 @@ lazy_static! {
 }
 
 #[derive(Debug, PartialEq, Clone)]
-pub struct Embedding(Vec<f32>);
+pub struct Embedding(pub Vec<f32>);
 
+// This is needed for semantic index functionality
+// Unfortunately it has to live wherever the "Embedding" struct is created.
+// Keeping this in here though, introduces a 'rusqlite' dependency into AI
+// which is less than ideal
+impl FromSql for Embedding {
+    fn column_result(value: ValueRef) -> FromSqlResult<Self> {
+        let bytes = value.as_blob()?;
+        let embedding: Result<Vec<f32>, Box<bincode::ErrorKind>> = bincode::deserialize(bytes);
+        if embedding.is_err() {
+            return Err(rusqlite::types::FromSqlError::Other(embedding.unwrap_err()));
+        }
+        Ok(Embedding(embedding.unwrap()))
+    }
+}
+
+impl ToSql for Embedding {
+    fn to_sql(&self) -> rusqlite::Result<ToSqlOutput> {
+        let bytes = bincode::serialize(&self.0)
+            .map_err(|err| rusqlite::Error::ToSqlConversionFailure(Box::new(err)))?;
+        Ok(ToSqlOutput::Owned(rusqlite::types::Value::Blob(bytes)))
+    }
+}
 impl From<Vec<f32>> for Embedding {
     fn from(value: Vec<f32>) -> Self {
         Embedding(value)
@@ -63,24 +85,24 @@ impl Embedding {
     }
 }
 
-impl FromSql for Embedding {
-    fn column_result(value: ValueRef) -> FromSqlResult<Self> {
-        let bytes = value.as_blob()?;
-        let embedding: Result<Vec<f32>, Box<bincode::ErrorKind>> = bincode::deserialize(bytes);
-        if embedding.is_err() {
-            return Err(rusqlite::types::FromSqlError::Other(embedding.unwrap_err()));
-        }
-        Ok(Embedding(embedding.unwrap()))
-    }
-}
+// impl FromSql for Embedding {
+//     fn column_result(value: ValueRef) -> FromSqlResult<Self> {
+//         let bytes = value.as_blob()?;
+//         let embedding: Result<Vec<f32>, Box<bincode::ErrorKind>> = bincode::deserialize(bytes);
+//         if embedding.is_err() {
+//             return Err(rusqlite::types::FromSqlError::Other(embedding.unwrap_err()));
+//         }
+//         Ok(Embedding(embedding.unwrap()))
+//     }
+// }
 
-impl ToSql for Embedding {
-    fn to_sql(&self) -> rusqlite::Result<ToSqlOutput> {
-        let bytes = bincode::serialize(&self.0)
-            .map_err(|err| rusqlite::Error::ToSqlConversionFailure(Box::new(err)))?;
-        Ok(ToSqlOutput::Owned(rusqlite::types::Value::Blob(bytes)))
-    }
-}
+// impl ToSql for Embedding {
+//     fn to_sql(&self) -> rusqlite::Result<ToSqlOutput> {
+//         let bytes = bincode::serialize(&self.0)
+//             .map_err(|err| rusqlite::Error::ToSqlConversionFailure(Box::new(err)))?;
+//         Ok(ToSqlOutput::Owned(rusqlite::types::Value::Blob(bytes)))
+//     }
+// }
 
 #[derive(Clone)]
 pub struct OpenAIEmbeddings {

crates/assistant/Cargo.toml

@@ -0,0 +1,48 @@
+[package]
+name = "assistant"
+version = "0.1.0"
+edition = "2021"
+publish = false
+
+[lib]
+path = "src/assistant.rs"
+doctest = false
+
+[dependencies]
+ai = { path = "../ai" }
+client = { path = "../client" }
+collections = { path = "../collections"}
+editor = { path = "../editor" }
+fs = { path = "../fs" }
+gpui = { path = "../gpui" }
+language = { path = "../language" }
+menu = { path = "../menu" }
+search = { path = "../search" }
+settings = { path = "../settings" }
+theme = { path = "../theme" }
+util = { path = "../util" }
+workspace = { path = "../workspace" }
+uuid.workspace = true
+
+anyhow.workspace = true
+chrono = { version = "0.4", features = ["serde"] }
+futures.workspace = true
+indoc.workspace = true
+isahc.workspace = true
+ordered-float.workspace = true
+parking_lot.workspace = true
+regex.workspace = true
+schemars.workspace = true
+serde.workspace = true
+serde_json.workspace = true
+smol.workspace = true
+tiktoken-rs = "0.4"
+
+[dev-dependencies]
+editor = { path = "../editor", features = ["test-support"] }
+project = { path = "../project", features = ["test-support"] }
+
+ctor.workspace = true
+env_logger.workspace = true
+log.workspace = true
+rand.workspace = true

crates/assistant/src/assistant.rs

@@ -0,0 +1,113 @@
+pub mod assistant_panel;
+mod assistant_settings;
+mod codegen;
+mod prompts;
+mod streaming_diff;
+
+use ai::completion::Role;
+use anyhow::Result;
+pub use assistant_panel::AssistantPanel;
+use assistant_settings::OpenAIModel;
+use chrono::{DateTime, Local};
+use collections::HashMap;
+use fs::Fs;
+use futures::StreamExt;
+use gpui::AppContext;
+use regex::Regex;
+use serde::{Deserialize, Serialize};
+use std::{cmp::Reverse, ffi::OsStr, path::PathBuf, sync::Arc};
+use util::paths::CONVERSATIONS_DIR;
+
+#[derive(
+    Copy, Clone, Debug, Default, Eq, PartialEq, PartialOrd, Ord, Hash, Serialize, Deserialize,
+)]
+struct MessageId(usize);
+
+#[derive(Clone, Debug, Serialize, Deserialize)]
+struct MessageMetadata {
+    role: Role,
+    sent_at: DateTime<Local>,
+    status: MessageStatus,
+}
+
+#[derive(Clone, Debug, Serialize, Deserialize)]
+enum MessageStatus {
+    Pending,
+    Done,
+    Error(Arc<str>),
+}
+
+#[derive(Serialize, Deserialize)]
+struct SavedMessage {
+    id: MessageId,
+    start: usize,
+}
+
+#[derive(Serialize, Deserialize)]
+struct SavedConversation {
+    id: Option<String>,
+    zed: String,
+    version: String,
+    text: String,
+    messages: Vec<SavedMessage>,
+    message_metadata: HashMap<MessageId, MessageMetadata>,
+    summary: String,
+    model: OpenAIModel,
+}
+
+impl SavedConversation {
+    const VERSION: &'static str = "0.1.0";
+}
+
+struct SavedConversationMetadata {
+    title: String,
+    path: PathBuf,
+    mtime: chrono::DateTime<chrono::Local>,
+}
+
+impl SavedConversationMetadata {
+    pub async fn list(fs: Arc<dyn Fs>) -> Result<Vec<Self>> {
+        fs.create_dir(&CONVERSATIONS_DIR).await?;
+
+        let mut paths = fs.read_dir(&CONVERSATIONS_DIR).await?;
+        let mut conversations = Vec::<SavedConversationMetadata>::new();
+        while let Some(path) = paths.next().await {
+            let path = path?;
+            if path.extension() != Some(OsStr::new("json")) {
+                continue;
+            }
+
+            let pattern = r" - \d+.zed.json$";
+            let re = Regex::new(pattern).unwrap();
+
+            let metadata = fs.metadata(&path).await?;
+            if let Some((file_name, metadata)) = path
+                .file_name()
+                .and_then(|name| name.to_str())
+                .zip(metadata)
+            {
+                let title = re.replace(file_name, "");
+                conversations.push(Self {
+                    title: title.into_owned(),
+                    path,
+                    mtime: metadata.mtime.into(),
+                });
+            }
+        }
+        conversations.sort_unstable_by_key(|conversation| Reverse(conversation.mtime));
+
+        Ok(conversations)
+    }
+}
+
+pub fn init(cx: &mut AppContext) {
+    assistant_panel::init(cx);
+}
+
+#[cfg(test)]
+#[ctor::ctor]
+fn init_logger() {
+    if std::env::var("RUST_LOG").is_ok() {
+        env_logger::init();
+    }
+}

crates/assistant/src/assistant_panel.rs

@@ -1,8 +1,12 @@
 use crate::{
     assistant_settings::{AssistantDockPosition, AssistantSettings, OpenAIModel},
-    codegen::{self, Codegen, CodegenKind, OpenAICompletionProvider},
-    stream_completion, MessageId, MessageMetadata, MessageStatus, OpenAIRequest, RequestMessage,
-    Role, SavedConversation, SavedConversationMetadata, SavedMessage, OPENAI_API_URL,
+    codegen::{self, Codegen, CodegenKind},
+    prompts::generate_content_prompt,
+    MessageId, MessageMetadata, MessageStatus, Role, SavedConversation, SavedConversationMetadata,
+    SavedMessage,
+};
+use ai::completion::{
+    stream_completion, OpenAICompletionProvider, OpenAIRequest, RequestMessage, OPENAI_API_URL,
 };
 use anyhow::{anyhow, Result};
 use chrono::{DateTime, Local};
@@ -13,7 +17,7 @@ use editor::{
         BlockContext, BlockDisposition, BlockId, BlockProperties, BlockStyle, ToDisplayPoint,
     },
     scroll::autoscroll::{Autoscroll, AutoscrollStrategy},
-    Anchor, Editor, MoveDown, MoveUp, MultiBufferSnapshot, ToOffset,
+    Anchor, Editor, MoveDown, MoveUp, MultiBufferSnapshot, ToOffset, ToPoint,
 };
 use fs::Fs;
 use futures::StreamExt;
@@ -270,22 +274,40 @@ impl AssistantPanel {
             return;
         };
 
-        let inline_assist_id = post_inc(&mut self.next_inline_assist_id);
+        let selection = editor.read(cx).selections.newest_anchor().clone();
+        if selection.start.excerpt_id() != selection.end.excerpt_id() {
+            return;
+        }
         let snapshot = editor.read(cx).buffer().read(cx).snapshot(cx);
+
+        // Extend the selection to the start and the end of the line.
+        let mut point_selection = selection.map(|selection| selection.to_point(&snapshot));
+        if point_selection.end > point_selection.start {
+            point_selection.start.column = 0;
+            // If the selection ends at the start of the line, we don't want to include it.
+            if point_selection.end.column == 0 {
+                point_selection.end.row -= 1;
+            }
+            point_selection.end.column = snapshot.line_len(point_selection.end.row);
+        }
+
+        let codegen_kind = if point_selection.start == point_selection.end {
+            CodegenKind::Generate {
+                position: snapshot.anchor_after(point_selection.start),
+            }
+        } else {
+            CodegenKind::Transform {
+                range: snapshot.anchor_before(point_selection.start)
+                    ..snapshot.anchor_after(point_selection.end),
+            }
+        };
+
+        let inline_assist_id = post_inc(&mut self.next_inline_assist_id);
         let provider = Arc::new(OpenAICompletionProvider::new(
             api_key,
             cx.background().clone(),
         ));
-        let selection = editor.read(cx).selections.newest_anchor().clone();
-        let codegen_kind = if editor.read(cx).selections.newest::<usize>(cx).is_empty() {
-            CodegenKind::Generate {
-                position: selection.start,
-            }
-        } else {
-            CodegenKind::Transform {
-                range: selection.start..selection.end,
-            }
-        };
+
         let codegen = cx.add_model(|cx| {
             Codegen::new(editor.read(cx).buffer().clone(), codegen_kind, provider, cx)
         });
@@ -311,7 +333,7 @@ impl AssistantPanel {
             editor.insert_blocks(
                 [BlockProperties {
                     style: BlockStyle::Flex,
-                    position: selection.head().bias_left(&snapshot),
+                    position: snapshot.anchor_before(point_selection.head()),
                     height: 2,
                     render: Arc::new({
                         let inline_assistant = inline_assistant.clone();
@@ -538,11 +560,26 @@ impl AssistantPanel {
             self.inline_prompt_history.pop_front();
         }
 
+        let codegen = pending_assist.codegen.clone();
         let snapshot = editor.read(cx).buffer().read(cx).snapshot(cx);
-        let range = pending_assist.codegen.read(cx).range();
-        let selected_text = snapshot.text_for_range(range.clone()).collect::<String>();
+        let range = codegen.read(cx).range();
+        let start = snapshot.point_to_buffer_offset(range.start);
+        let end = snapshot.point_to_buffer_offset(range.end);
+        let (buffer, range) = if let Some((start, end)) = start.zip(end) {
+            let (start_buffer, start_buffer_offset) = start;
+            let (end_buffer, end_buffer_offset) = end;
+            if start_buffer.remote_id() == end_buffer.remote_id() {
+                (start_buffer.clone(), start_buffer_offset..end_buffer_offset)
+            } else {
+                self.finish_inline_assist(inline_assist_id, false, cx);
+                return;
+            }
+        } else {
+            self.finish_inline_assist(inline_assist_id, false, cx);
+            return;
+        };
 
-        let language = snapshot.language_at(range.start);
+        let language = buffer.language_at(range.start);
         let language_name = if let Some(language) = language.as_ref() {
             if Arc::ptr_eq(language, &language::PLAIN_TEXT) {
                 None
@@ -552,95 +589,9 @@ impl AssistantPanel {
         } else {
             None
         };
-        let language_name = language_name.as_deref();
 
-        let mut prompt = String::new();
-        if let Some(language_name) = language_name {
-            writeln!(prompt, "You're an expert {language_name} engineer.").unwrap();
-        }
-        match pending_assist.codegen.read(cx).kind() {
-            CodegenKind::Transform { .. } => {
-                writeln!(
-                    prompt,
-                    "You're currently working inside an editor on this file:"
-                )
-                .unwrap();
-                if let Some(language_name) = language_name {
-                    writeln!(prompt, "```{language_name}").unwrap();
-                } else {
-                    writeln!(prompt, "```").unwrap();
-                }
-                for chunk in snapshot.text_for_range(Anchor::min()..Anchor::max()) {
-                    write!(prompt, "{chunk}").unwrap();
-                }
-                writeln!(prompt, "```").unwrap();
-
-                writeln!(
-                    prompt,
-                    "In particular, the user has selected the following text:"
-                )
-                .unwrap();
-                if let Some(language_name) = language_name {
-                    writeln!(prompt, "```{language_name}").unwrap();
-                } else {
-                    writeln!(prompt, "```").unwrap();
-                }
-                writeln!(prompt, "{selected_text}").unwrap();
-                writeln!(prompt, "```").unwrap();
-                writeln!(prompt).unwrap();
-                writeln!(
-                    prompt,
-                    "Modify the selected text given the user prompt: {user_prompt}"
-                )
-                .unwrap();
-                writeln!(
-                    prompt,
-                    "You MUST reply only with the edited selected text, not the entire file."
-                )
-                .unwrap();
-            }
-            CodegenKind::Generate { .. } => {
-                writeln!(
-                    prompt,
-                    "You're currently working inside an editor on this file:"
-                )
-                .unwrap();
-                if let Some(language_name) = language_name {
-                    writeln!(prompt, "```{language_name}").unwrap();
-                } else {
-                    writeln!(prompt, "```").unwrap();
-                }
-                for chunk in snapshot.text_for_range(Anchor::min()..range.start) {
-                    write!(prompt, "{chunk}").unwrap();
-                }
-                write!(prompt, "<|>").unwrap();
-                for chunk in snapshot.text_for_range(range.start..Anchor::max()) {
-                    write!(prompt, "{chunk}").unwrap();
-                }
-                writeln!(prompt).unwrap();
-                writeln!(prompt, "```").unwrap();
-                writeln!(
-                    prompt,
-                    "Assume the cursor is located where the `<|>` marker is."
-                )
-                .unwrap();
-                writeln!(
-                    prompt,
-                    "Text can't be replaced, so assume your answer will be inserted at the cursor."
-                )
-                .unwrap();
-                writeln!(
-                    prompt,
-                    "Complete the text given the user prompt: {user_prompt}"
-                )
-                .unwrap();
-            }
-        }
-        if let Some(language_name) = language_name {
-            writeln!(prompt, "Your answer MUST always be valid {language_name}.").unwrap();
-        }
-        writeln!(prompt, "Always wrap your response in a Markdown codeblock.").unwrap();
-        writeln!(prompt, "Never make remarks about the output.").unwrap();
+        let codegen_kind = codegen.read(cx).kind().clone();
+        let user_prompt = user_prompt.to_string();
 
         let mut messages = Vec::new();
         let mut model = settings::get::<AssistantSettings>(cx)
@@ -657,18 +608,26 @@ impl AssistantPanel {
             model = conversation.model.clone();
         }
 
-        messages.push(RequestMessage {
-            role: Role::User,
-            content: prompt,
+        let prompt = cx.background().spawn(async move {
+            let language_name = language_name.as_deref();
+            generate_content_prompt(user_prompt, language_name, &buffer, range, codegen_kind)
         });
-        let request = OpenAIRequest {
-            model: model.full_name().into(),
-            messages,
-            stream: true,
-        };
-        pending_assist
-            .codegen
-            .update(cx, |codegen, cx| codegen.start(request, cx));
+
+        cx.spawn(|_, mut cx| async move {
+            let prompt = prompt.await;
+
+            messages.push(RequestMessage {
+                role: Role::User,
+                content: prompt,
+            });
+            let request = OpenAIRequest {
+                model: model.full_name().into(),
+                messages,
+                stream: true,
+            };
+            codegen.update(&mut cx, |codegen, cx| codegen.start(request, cx));
+        })
+        .detach();
     }
 
     fn update_highlights_for_editor(

crates/assistant/src/codegen.rs

@@ -1,59 +1,12 @@
-use crate::{
-    stream_completion,
-    streaming_diff::{Hunk, StreamingDiff},
-    OpenAIRequest,
-};
+use crate::streaming_diff::{Hunk, StreamingDiff};
+use ai::completion::{CompletionProvider, OpenAIRequest};
 use anyhow::Result;
-use editor::{
-    multi_buffer, Anchor, AnchorRangeExt, MultiBuffer, MultiBufferSnapshot, ToOffset, ToPoint,
-};
-use futures::{
-    channel::mpsc, future::BoxFuture, stream::BoxStream, FutureExt, SinkExt, Stream, StreamExt,
-};
-use gpui::{executor::Background, Entity, ModelContext, ModelHandle, Task};
+use editor::{multi_buffer, Anchor, MultiBuffer, MultiBufferSnapshot, ToOffset, ToPoint};
+use futures::{channel::mpsc, SinkExt, Stream, StreamExt};
+use gpui::{Entity, ModelContext, ModelHandle, Task};
 use language::{Rope, TransactionId};
 use std::{cmp, future, ops::Range, sync::Arc};
 
-pub trait CompletionProvider {
-    fn complete(
-        &self,
-        prompt: OpenAIRequest,
-    ) -> BoxFuture<'static, Result<BoxStream<'static, Result<String>>>>;
-}
-
-pub struct OpenAICompletionProvider {
-    api_key: String,
-    executor: Arc<Background>,
-}
-
-impl OpenAICompletionProvider {
-    pub fn new(api_key: String, executor: Arc<Background>) -> Self {
-        Self { api_key, executor }
-    }
-}
-
-impl CompletionProvider for OpenAICompletionProvider {
-    fn complete(
-        &self,
-        prompt: OpenAIRequest,
-    ) -> BoxFuture<'static, Result<BoxStream<'static, Result<String>>>> {
-        let request = stream_completion(self.api_key.clone(), self.executor.clone(), prompt);
-        async move {
-            let response = request.await?;
-            let stream = response
-                .filter_map(|response| async move {
-                    match response {
-                        Ok(mut response) => Some(Ok(response.choices.pop()?.delta.content?)),
-                        Err(error) => Some(Err(error)),
-                    }
-                })
-                .boxed();
-            Ok(stream)
-        }
-        .boxed()
-    }
-}
-
 pub enum Event {
     Finished,
     Undone,
@@ -85,26 +38,11 @@ impl Entity for Codegen {
 impl Codegen {
     pub fn new(
         buffer: ModelHandle<MultiBuffer>,
-        mut kind: CodegenKind,
+        kind: CodegenKind,
         provider: Arc<dyn CompletionProvider>,
         cx: &mut ModelContext<Self>,
     ) -> Self {
         let snapshot = buffer.read(cx).snapshot(cx);
-        match &mut kind {
-            CodegenKind::Transform { range } => {
-                let mut point_range = range.to_point(&snapshot);
-                point_range.start.column = 0;
-                if point_range.end.column > 0 || point_range.start.row == point_range.end.row {
-                    point_range.end.column = snapshot.line_len(point_range.end.row);
-                }
-                range.start = snapshot.anchor_before(point_range.start);
-                range.end = snapshot.anchor_after(point_range.end);
-            }
-            CodegenKind::Generate { position } => {
-                *position = position.bias_right(&snapshot);
-            }
-        }
-
         Self {
             provider,
             buffer: buffer.clone(),
@@ -397,13 +335,17 @@ fn strip_markdown_codeblock(
 #[cfg(test)]
 mod tests {
     use super::*;
-    use futures::stream;
+    use futures::{
+        future::BoxFuture,
+        stream::{self, BoxStream},
+    };
     use gpui::{executor::Deterministic, TestAppContext};
     use indoc::indoc;
     use language::{language_settings, tree_sitter_rust, Buffer, Language, LanguageConfig, Point};
     use parking_lot::Mutex;
     use rand::prelude::*;
     use settings::SettingsStore;
+    use smol::future::FutureExt;
 
     #[gpui::test(iterations = 10)]
     async fn test_transform_autoindent(
@@ -427,7 +369,7 @@ mod tests {
         let buffer = cx.add_model(|cx| MultiBuffer::singleton(buffer, cx));
         let range = buffer.read_with(cx, |buffer, cx| {
             let snapshot = buffer.snapshot(cx);
-            snapshot.anchor_before(Point::new(1, 4))..snapshot.anchor_after(Point::new(4, 4))
+            snapshot.anchor_before(Point::new(1, 0))..snapshot.anchor_after(Point::new(4, 5))
         });
         let provider = Arc::new(TestCompletionProvider::new());
         let codegen = cx.add_model(|cx| {

crates/assistant/src/prompts.rs

@@ -0,0 +1,418 @@
+use crate::codegen::CodegenKind;
+use language::{BufferSnapshot, OffsetRangeExt, ToOffset};
+use std::cmp::{self, Reverse};
+use std::fmt::Write;
+use std::ops::Range;
+
+#[allow(dead_code)]
+fn summarize(buffer: &BufferSnapshot, selected_range: Range<impl ToOffset>) -> String {
+    #[derive(Debug)]
+    struct Match {
+        collapse: Range<usize>,
+        keep: Vec<Range<usize>>,
+    }
+
+    let selected_range = selected_range.to_offset(buffer);
+    let mut ts_matches = buffer.matches(0..buffer.len(), |grammar| {
+        Some(&grammar.embedding_config.as_ref()?.query)
+    });
+    let configs = ts_matches
+        .grammars()
+        .iter()
+        .map(|g| g.embedding_config.as_ref().unwrap())
+        .collect::<Vec<_>>();
+    let mut matches = Vec::new();
+    while let Some(mat) = ts_matches.peek() {
+        let config = &configs[mat.grammar_index];
+        if let Some(collapse) = mat.captures.iter().find_map(|cap| {
+            if Some(cap.index) == config.collapse_capture_ix {
+                Some(cap.node.byte_range())
+            } else {
+                None
+            }
+        }) {
+            let mut keep = Vec::new();
+            for capture in mat.captures.iter() {
+                if Some(capture.index) == config.keep_capture_ix {
+                    keep.push(capture.node.byte_range());
+                } else {
+                    continue;
+                }
+            }
+            ts_matches.advance();
+            matches.push(Match { collapse, keep });
+        } else {
+            ts_matches.advance();
+        }
+    }
+    matches.sort_unstable_by_key(|mat| (mat.collapse.start, Reverse(mat.collapse.end)));
+    let mut matches = matches.into_iter().peekable();
+
+    let mut summary = String::new();
+    let mut offset = 0;
+    let mut flushed_selection = false;
+    while let Some(mat) = matches.next() {
+        // Keep extending the collapsed range if the next match surrounds
+        // the current one.
+        while let Some(next_mat) = matches.peek() {
+            if mat.collapse.start <= next_mat.collapse.start
+                && mat.collapse.end >= next_mat.collapse.end
+            {
+                matches.next().unwrap();
+            } else {
+                break;
+            }
+        }
+
+        if offset > mat.collapse.start {
+            // Skip collapsed nodes that have already been summarized.
+            offset = cmp::max(offset, mat.collapse.end);
+            continue;
+        }
+
+        if offset <= selected_range.start && selected_range.start <= mat.collapse.end {
+            if !flushed_selection {
+                // The collapsed node ends after the selection starts, so we'll flush the selection first.
+                summary.extend(buffer.text_for_range(offset..selected_range.start));
+                summary.push_str("<|START|");
+                if selected_range.end == selected_range.start {
+                    summary.push_str(">");
+                } else {
+                    summary.extend(buffer.text_for_range(selected_range.clone()));
+                    summary.push_str("|END|>");
+                }
+                offset = selected_range.end;
+                flushed_selection = true;
+            }
+
+            // If the selection intersects the collapsed node, we won't collapse it.
+            if selected_range.end >= mat.collapse.start {
+                continue;
+            }
+        }
+
+        summary.extend(buffer.text_for_range(offset..mat.collapse.start));
+        for keep in mat.keep {
+            summary.extend(buffer.text_for_range(keep));
+        }
+        offset = mat.collapse.end;
+    }
+
+    // Flush selection if we haven't already done so.
+    if !flushed_selection && offset <= selected_range.start {
+        summary.extend(buffer.text_for_range(offset..selected_range.start));
+        summary.push_str("<|START|");
+        if selected_range.end == selected_range.start {
+            summary.push_str(">");
+        } else {
+            summary.extend(buffer.text_for_range(selected_range.clone()));
+            summary.push_str("|END|>");
+        }
+        offset = selected_range.end;
+    }
+
+    summary.extend(buffer.text_for_range(offset..buffer.len()));
+    summary
+}
+
+pub fn generate_content_prompt(
+    user_prompt: String,
+    language_name: Option<&str>,
+    buffer: &BufferSnapshot,
+    range: Range<impl ToOffset>,
+    kind: CodegenKind,
+) -> String {
+    let range = range.to_offset(buffer);
+    let mut prompt = String::new();
+
+    // General Preamble
+    if let Some(language_name) = language_name {
+        writeln!(prompt, "You're an expert {language_name} engineer.\n").unwrap();
+    } else {
+        writeln!(prompt, "You're an expert engineer.\n").unwrap();
+    }
+
+    let mut content = String::new();
+    content.extend(buffer.text_for_range(0..range.start));
+    if range.start == range.end {
+        content.push_str("<|START|>");
+    } else {
+        content.push_str("<|START|");
+    }
+    content.extend(buffer.text_for_range(range.clone()));
+    if range.start != range.end {
+        content.push_str("|END|>");
+    }
+    content.extend(buffer.text_for_range(range.end..buffer.len()));
+
+    writeln!(
+        prompt,
+        "The file you are currently working on has the following content:"
+    )
+    .unwrap();
+    if let Some(language_name) = language_name {
+        let language_name = language_name.to_lowercase();
+        writeln!(prompt, "```{language_name}\n{content}\n```").unwrap();
+    } else {
+        writeln!(prompt, "```\n{content}\n```").unwrap();
+    }
+
+    match kind {
+        CodegenKind::Generate { position: _ } => {
+            writeln!(prompt, "In particular, the user's cursor is current on the '<|START|>' span in the above outline, with no text selected.").unwrap();
+            writeln!(
+                prompt,
+                "Assume the cursor is located where the `<|START|` marker is."
+            )
+            .unwrap();
+            writeln!(
+                prompt,
+                "Text can't be replaced, so assume your answer will be inserted at the cursor."
+            )
+            .unwrap();
+            writeln!(
+                prompt,
+                "Generate text based on the users prompt: {user_prompt}"
+            )
+            .unwrap();
+        }
+        CodegenKind::Transform { range: _ } => {
+            writeln!(prompt, "In particular, the user has selected a section of the text between the '<|START|' and '|END|>' spans.").unwrap();
+            writeln!(
+                prompt,
+                "Modify the users code selected text based upon the users prompt: {user_prompt}"
+            )
+            .unwrap();
+            writeln!(
+                prompt,
+                "You MUST reply with only the adjusted code (within the '<|START|' and '|END|>' spans), not the entire file."
+            )
+            .unwrap();
+        }
+    }
+
+    if let Some(language_name) = language_name {
+        writeln!(prompt, "Your answer MUST always be valid {language_name}").unwrap();
+    }
+    writeln!(prompt, "Always wrap your response in a Markdown codeblock").unwrap();
+    writeln!(prompt, "Never make remarks about the output.").unwrap();
+
+    prompt
+}
+
+#[cfg(test)]
+pub(crate) mod tests {
+
+    use super::*;
+    use std::sync::Arc;
+
+    use gpui::AppContext;
+    use indoc::indoc;
+    use language::{language_settings, tree_sitter_rust, Buffer, Language, LanguageConfig, Point};
+    use settings::SettingsStore;
+
+    pub(crate) fn rust_lang() -> Language {
+        Language::new(
+            LanguageConfig {
+                name: "Rust".into(),
+                path_suffixes: vec!["rs".to_string()],
+                ..Default::default()
+            },
+            Some(tree_sitter_rust::language()),
+        )
+        .with_embedding_query(
+            r#"
+            (
+                [(line_comment) (attribute_item)]* @context
+                .
+                [
+                    (struct_item
+                        name: (_) @name)
+
+                    (enum_item
+                        name: (_) @name)
+
+                    (impl_item
+                        trait: (_)? @name
+                        "for"? @name
+                        type: (_) @name)
+
+                    (trait_item
+                        name: (_) @name)
+
+                    (function_item
+                        name: (_) @name
+                        body: (block
+                            "{" @keep
+                            "}" @keep) @collapse)
+
+                    (macro_definition
+                        name: (_) @name)
+                    ] @item
+                )
+            "#,
+        )
+        .unwrap()
+    }
+
+    #[gpui::test]
+    fn test_outline_for_prompt(cx: &mut AppContext) {
+        cx.set_global(SettingsStore::test(cx));
+        language_settings::init(cx);
+        let text = indoc! {"
+            struct X {
+                a: usize,
+                b: usize,
+            }
+
+            impl X {
+
+                fn new() -> Self {
+                    let a = 1;
+                    let b = 2;
+                    Self { a, b }
+                }
+
+                pub fn a(&self, param: bool) -> usize {
+                    self.a
+                }
+
+                pub fn b(&self) -> usize {
+                    self.b
+                }
+            }
+        "};
+        let buffer =
+            cx.add_model(|cx| Buffer::new(0, 0, text).with_language(Arc::new(rust_lang()), cx));
+        let snapshot = buffer.read(cx).snapshot();
+
+        assert_eq!(
+            summarize(&snapshot, Point::new(1, 4)..Point::new(1, 4)),
+            indoc! {"
+                struct X {
+                    <|START|>a: usize,
+                    b: usize,
+                }
+
+                impl X {
+
+                    fn new() -> Self {}
+
+                    pub fn a(&self, param: bool) -> usize {}
+
+                    pub fn b(&self) -> usize {}
+                }
+            "}
+        );
+
+        assert_eq!(
+            summarize(&snapshot, Point::new(8, 12)..Point::new(8, 14)),
+            indoc! {"
+                struct X {
+                    a: usize,
+                    b: usize,
+                }
+
+                impl X {
+
+                    fn new() -> Self {
+                        let <|START|a |END|>= 1;
+                        let b = 2;
+                        Self { a, b }
+                    }
+
+                    pub fn a(&self, param: bool) -> usize {}
+
+                    pub fn b(&self) -> usize {}
+                }
+            "}
+        );
+
+        assert_eq!(
+            summarize(&snapshot, Point::new(6, 0)..Point::new(6, 0)),
+            indoc! {"
+                struct X {
+                    a: usize,
+                    b: usize,
+                }
+
+                impl X {
+                <|START|>
+                    fn new() -> Self {}
+
+                    pub fn a(&self, param: bool) -> usize {}
+
+                    pub fn b(&self) -> usize {}
+                }
+            "}
+        );
+
+        assert_eq!(
+            summarize(&snapshot, Point::new(21, 0)..Point::new(21, 0)),
+            indoc! {"
+                struct X {
+                    a: usize,
+                    b: usize,
+                }
+
+                impl X {
+
+                    fn new() -> Self {}
+
+                    pub fn a(&self, param: bool) -> usize {}
+
+                    pub fn b(&self) -> usize {}
+                }
+                <|START|>"}
+        );
+
+        // Ensure nested functions get collapsed properly.
+        let text = indoc! {"
+            struct X {
+                a: usize,
+                b: usize,
+            }
+
+            impl X {
+
+                fn new() -> Self {
+                    let a = 1;
+                    let b = 2;
+                    Self { a, b }
+                }
+
+                pub fn a(&self, param: bool) -> usize {
+                    let a = 30;
+                    fn nested() -> usize {
+                        3
+                    }
+                    self.a + nested()
+                }
+
+                pub fn b(&self) -> usize {
+                    self.b
+                }
+            }
+        "};
+        buffer.update(cx, |buffer, cx| buffer.set_text(text, cx));
+        let snapshot = buffer.read(cx).snapshot();
+        assert_eq!(
+            summarize(&snapshot, Point::new(0, 0)..Point::new(0, 0)),
+            indoc! {"
+                <|START|>struct X {
+                    a: usize,
+                    b: usize,
+                }
+
+                impl X {
+
+                    fn new() -> Self {}
+
+                    pub fn a(&self, param: bool) -> usize {}
+
+                    pub fn b(&self) -> usize {}
+                }
+            "}
+        );
+    }
+}

crates/auto_update/src/auto_update.rs

@@ -115,13 +115,15 @@ pub fn check(_: &Check, cx: &mut AppContext) {
 
 fn view_release_notes(_: &ViewReleaseNotes, cx: &mut AppContext) {
     if let Some(auto_updater) = AutoUpdater::get(cx) {
-        let server_url = &auto_updater.read(cx).server_url;
+        let auto_updater = auto_updater.read(cx);
+        let server_url = &auto_updater.server_url;
+        let current_version = auto_updater.current_version;
         let latest_release_url = if cx.has_global::<ReleaseChannel>()
             && *cx.global::<ReleaseChannel>() == ReleaseChannel::Preview
         {
-            format!("{server_url}/releases/preview/latest")
+            format!("{server_url}/releases/preview/{current_version}")
         } else {
-            format!("{server_url}/releases/stable/latest")
+            format!("{server_url}/releases/stable/{current_version}")
         };
         cx.platform().open_url(&latest_release_url);
     }

crates/call/src/call.rs

@@ -2,22 +2,23 @@ pub mod call_settings;
 pub mod participant;
 pub mod room;
 
-use std::sync::Arc;
-
 use anyhow::{anyhow, Result};
 use audio::Audio;
 use call_settings::CallSettings;
 use channel::ChannelId;
-use client::{proto, ClickhouseEvent, Client, TelemetrySettings, TypedEnvelope, User, UserStore};
+use client::{
+    proto, ClickhouseEvent, Client, TelemetrySettings, TypedEnvelope, User, UserStore,
+    ZED_ALWAYS_ACTIVE,
+};
 use collections::HashSet;
 use futures::{future::Shared, FutureExt};
-use postage::watch;
-
 use gpui::{
     AppContext, AsyncAppContext, Entity, ModelContext, ModelHandle, Subscription, Task,
     WeakModelHandle,
 };
+use postage::watch;
 use project::Project;
+use std::sync::Arc;
 
 pub use participant::ParticipantLocation;
 pub use room::Room;
@@ -68,6 +69,7 @@ impl ActiveCall {
             location: None,
             pending_invites: Default::default(),
             incoming_call: watch::channel(),
+
             _subscriptions: vec![
                 client.add_request_handler(cx.handle(), Self::handle_incoming_call),
                 client.add_message_handler(cx.handle(), Self::handle_call_canceled),
@@ -206,9 +208,14 @@ impl ActiveCall {
 
         cx.spawn(|this, mut cx| async move {
             let result = invite.await;
+            if result.is_ok() {
+                this.update(&mut cx, |this, cx| this.report_call_event("invite", cx));
+            } else {
+                // TODO: Resport collaboration error
+            }
+
             this.update(&mut cx, |this, cx| {
                 this.pending_invites.remove(&called_user_id);
-                this.report_call_event("invite", cx);
                 cx.notify();
             });
             result
@@ -273,13 +280,7 @@ impl ActiveCall {
             .borrow_mut()
             .take()
             .ok_or_else(|| anyhow!("no incoming call"))?;
-        Self::report_call_event_for_room(
-            "decline incoming",
-            Some(call.room_id),
-            None,
-            &self.client,
-            cx,
-        );
+        report_call_event_for_room("decline incoming", call.room_id, None, &self.client, cx);
         self.client.send(proto::DeclineCall {
             room_id: call.room_id,
         })?;
@@ -290,10 +291,10 @@ impl ActiveCall {
         &mut self,
         channel_id: u64,
         cx: &mut ModelContext<Self>,
-    ) -> Task<Result<()>> {
+    ) -> Task<Result<ModelHandle<Room>>> {
         if let Some(room) = self.room().cloned() {
             if room.read(cx).channel_id() == Some(channel_id) {
-                return Task::ready(Ok(()));
+                return Task::ready(Ok(room));
             } else {
                 room.update(cx, |room, cx| room.clear_state(cx));
             }
@@ -308,7 +309,7 @@ impl ActiveCall {
             this.update(&mut cx, |this, cx| {
                 this.report_call_event("join channel", cx)
             });
-            Ok(())
+            Ok(room)
         })
     }
 
@@ -349,17 +350,22 @@ impl ActiveCall {
         }
     }
 
+    pub fn location(&self) -> Option<&WeakModelHandle<Project>> {
+        self.location.as_ref()
+    }
+
     pub fn set_location(
         &mut self,
         project: Option<&ModelHandle<Project>>,
         cx: &mut ModelContext<Self>,
     ) -> Task<Result<()>> {
-        self.location = project.map(|project| project.downgrade());
-        if let Some((room, _)) = self.room.as_ref() {
-            room.update(cx, |room, cx| room.set_location(project, cx))
-        } else {
-            Task::ready(Ok(()))
+        if project.is_some() || !*ZED_ALWAYS_ACTIVE {
+            self.location = project.map(|project| project.downgrade());
+            if let Some((room, _)) = self.room.as_ref() {
+                return room.update(cx, |room, cx| room.set_location(project, cx));
+            }
         }
+        Task::ready(Ok(()))
     }
 
     fn set_room(
@@ -409,31 +415,46 @@ impl ActiveCall {
         &self.pending_invites
     }
 
-    fn report_call_event(&self, operation: &'static str, cx: &AppContext) {
-        let (room_id, channel_id) = match self.room() {
-            Some(room) => {
-                let room = room.read(cx);
-                (Some(room.id()), room.channel_id())
-            }
-            None => (None, None),
-        };
-        Self::report_call_event_for_room(operation, room_id, channel_id, &self.client, cx)
-    }
-
-    pub fn report_call_event_for_room(
-        operation: &'static str,
-        room_id: Option<u64>,
-        channel_id: Option<u64>,
-        client: &Arc<Client>,
-        cx: &AppContext,
-    ) {
-        let telemetry = client.telemetry();
-        let telemetry_settings = *settings::get::<TelemetrySettings>(cx);
-        let event = ClickhouseEvent::Call {
-            operation,
-            room_id,
-            channel_id,
-        };
-        telemetry.report_clickhouse_event(event, telemetry_settings);
+    pub fn report_call_event(&self, operation: &'static str, cx: &AppContext) {
+        if let Some(room) = self.room() {
+            let room = room.read(cx);
+            report_call_event_for_room(operation, room.id(), room.channel_id(), &self.client, cx);
+        }
     }
 }
+
+pub fn report_call_event_for_room(
+    operation: &'static str,
+    room_id: u64,
+    channel_id: Option<u64>,
+    client: &Arc<Client>,
+    cx: &AppContext,
+) {
+    let telemetry = client.telemetry();
+    let telemetry_settings = *settings::get::<TelemetrySettings>(cx);
+    let event = ClickhouseEvent::Call {
+        operation,
+        room_id: Some(room_id),
+        channel_id,
+    };
+    telemetry.report_clickhouse_event(event, telemetry_settings);
+}
+
+pub fn report_call_event_for_channel(
+    operation: &'static str,
+    channel_id: u64,
+    client: &Arc<Client>,
+    cx: &AppContext,
+) {
+    let room = ActiveCall::global(cx).read(cx).room();
+
+    let telemetry = client.telemetry();
+    let telemetry_settings = *settings::get::<TelemetrySettings>(cx);
+
+    let event = ClickhouseEvent::Call {
+        operation,
+        room_id: room.map(|r| r.read(cx).id()),
+        channel_id: Some(channel_id),
+    };
+    telemetry.report_clickhouse_event(event, telemetry_settings);
+}

crates/call/src/participant.rs

@@ -1,4 +1,5 @@
 use anyhow::{anyhow, Result};
+use client::ParticipantIndex;
 use client::{proto, User};
 use collections::HashMap;
 use gpui::WeakModelHandle;
@@ -43,6 +44,7 @@ pub struct RemoteParticipant {
     pub peer_id: proto::PeerId,
     pub projects: Vec<proto::ParticipantProject>,
     pub location: ParticipantLocation,
+    pub participant_index: ParticipantIndex,
     pub muted: bool,
     pub speaking: bool,
     pub video_tracks: HashMap<live_kit_client::Sid, Arc<RemoteVideoTrack>>,

crates/call/src/room.rs

@@ -7,7 +7,7 @@ use anyhow::{anyhow, Result};
 use audio::{Audio, Sound};
 use client::{
     proto::{self, PeerId},
-    Client, TypedEnvelope, User, UserStore,
+    Client, ParticipantIndex, TypedEnvelope, User, UserStore,
 };
 use collections::{BTreeMap, HashMap, HashSet};
 use fs::Fs;
@@ -44,6 +44,12 @@ pub enum Event {
     RemoteProjectUnshared {
         project_id: u64,
     },
+    RemoteProjectJoined {
+        project_id: u64,
+    },
+    RemoteProjectInvitationDiscarded {
+        project_id: u64,
+    },
     Left,
 }
 
@@ -98,6 +104,10 @@ impl Room {
         self.channel_id
     }
 
+    pub fn is_sharing_project(&self) -> bool {
+        !self.shared_projects.is_empty()
+    }
+
     #[cfg(any(test, feature = "test-support"))]
     pub fn is_connected(&self) -> bool {
         if let Some(live_kit) = self.live_kit.as_ref() {
@@ -588,6 +598,34 @@ impl Room {
             .map_or(&[], |v| v.as_slice())
     }
 
+    /// Returns the most 'active' projects, defined as most people in the project
+    pub fn most_active_project(&self) -> Option<(u64, u64)> {
+        let mut project_hosts_and_guest_counts = HashMap::<u64, (Option<u64>, u32)>::default();
+        for participant in self.remote_participants.values() {
+            match participant.location {
+                ParticipantLocation::SharedProject { project_id } => {
+                    project_hosts_and_guest_counts
+                        .entry(project_id)
+                        .or_default()
+                        .1 += 1;
+                }
+                ParticipantLocation::External | ParticipantLocation::UnsharedProject => {}
+            }
+            for project in &participant.projects {
+                project_hosts_and_guest_counts
+                    .entry(project.id)
+                    .or_default()
+                    .0 = Some(participant.user.id);
+            }
+        }
+
+        project_hosts_and_guest_counts
+            .into_iter()
+            .filter_map(|(id, (host, guest_count))| Some((id, host?, guest_count)))
+            .max_by_key(|(_, _, guest_count)| *guest_count)
+            .map(|(id, host, _)| (id, host))
+    }
+
     async fn handle_room_updated(
         this: ModelHandle<Self>,
         envelope: TypedEnvelope<proto::RoomUpdated>,
@@ -651,6 +689,7 @@ impl Room {
                         let Some(peer_id) = participant.peer_id else {
                             continue;
                         };
+                        let participant_index = ParticipantIndex(participant.participant_index);
                         this.participant_user_ids.insert(participant.user_id);
 
                         let old_projects = this
@@ -701,8 +740,9 @@ impl Room {
                         if let Some(remote_participant) =
                             this.remote_participants.get_mut(&participant.user_id)
                         {
-                            remote_participant.projects = participant.projects;
                             remote_participant.peer_id = peer_id;
+                            remote_participant.projects = participant.projects;
+                            remote_participant.participant_index = participant_index;
                             if location != remote_participant.location {
                                 remote_participant.location = location;
                                 cx.emit(Event::ParticipantLocationChanged {
@@ -714,6 +754,7 @@ impl Room {
                                 participant.user_id,
                                 RemoteParticipant {
                                     user: user.clone(),
+                                    participant_index,
                                     peer_id,
                                     projects: participant.projects,
                                     location,
@@ -807,6 +848,15 @@ impl Room {
                     let _ = this.leave(cx);
                 }
 
+                this.user_store.update(cx, |user_store, cx| {
+                    let participant_indices_by_user_id = this
+                        .remote_participants
+                        .iter()
+                        .map(|(user_id, participant)| (*user_id, participant.participant_index))
+                        .collect();
+                    user_store.set_participant_indices(participant_indices_by_user_id, cx);
+                });
+
                 this.check_invariants();
                 cx.notify();
             });
@@ -1003,6 +1053,7 @@ impl Room {
     ) -> Task<Result<ModelHandle<Project>>> {
         let client = self.client.clone();
         let user_store = self.user_store.clone();
+        cx.emit(Event::RemoteProjectJoined { project_id: id });
         cx.spawn(|this, mut cx| async move {
             let project =
                 Project::remote(id, client, user_store, language_registry, fs, cx.clone()).await?;

crates/channel/Cargo.toml

@@ -23,6 +23,7 @@ language = { path = "../language" }
 settings = { path = "../settings" }
 feature_flags = { path = "../feature_flags" }
 sum_tree = { path = "../sum_tree" }
+clock = { path = "../clock" }
 
 anyhow.workspace = true
 futures.workspace = true
@@ -38,7 +39,7 @@ smol.workspace = true
 thiserror.workspace = true
 time.workspace = true
 tiny_http = "0.8"
-uuid = { version = "1.1.2", features = ["v4"] }
+uuid.workspace = true
 url = "2.2"
 serde.workspace = true
 serde_derive.workspace = true

crates/channel/src/channel.rs

@@ -2,7 +2,7 @@ mod channel_buffer;
 mod channel_chat;
 mod channel_store;
 
-pub use channel_buffer::{ChannelBuffer, ChannelBufferEvent};
+pub use channel_buffer::{ChannelBuffer, ChannelBufferEvent, ACKNOWLEDGE_DEBOUNCE_INTERVAL};
 pub use channel_chat::{ChannelChat, ChannelChatEvent, ChannelMessage, ChannelMessageId};
 pub use channel_store::{
     Channel, ChannelData, ChannelEvent, ChannelId, ChannelMembership, ChannelPath, ChannelStore,

crates/channel/src/channel_buffer.rs

@@ -1,31 +1,39 @@
 use crate::Channel;
 use anyhow::Result;
-use client::Client;
-use gpui::{AppContext, AsyncAppContext, Entity, ModelContext, ModelHandle};
-use rpc::{proto, TypedEnvelope};
-use std::sync::Arc;
+use client::{Client, Collaborator, UserStore};
+use collections::HashMap;
+use gpui::{AppContext, AsyncAppContext, Entity, ModelContext, ModelHandle, Task};
+use language::proto::serialize_version;
+use rpc::{
+    proto::{self, PeerId},
+    TypedEnvelope,
+};
+use std::{sync::Arc, time::Duration};
 use util::ResultExt;
 
+pub const ACKNOWLEDGE_DEBOUNCE_INTERVAL: Duration = Duration::from_millis(250);
+
 pub(crate) fn init(client: &Arc<Client>) {
     client.add_model_message_handler(ChannelBuffer::handle_update_channel_buffer);
-    client.add_model_message_handler(ChannelBuffer::handle_add_channel_buffer_collaborator);
-    client.add_model_message_handler(ChannelBuffer::handle_remove_channel_buffer_collaborator);
-    client.add_model_message_handler(ChannelBuffer::handle_update_channel_buffer_collaborator);
+    client.add_model_message_handler(ChannelBuffer::handle_update_channel_buffer_collaborators);
 }
 
 pub struct ChannelBuffer {
     pub(crate) channel: Arc<Channel>,
     connected: bool,
-    collaborators: Vec<proto::Collaborator>,
+    collaborators: HashMap<PeerId, Collaborator>,
+    user_store: ModelHandle<UserStore>,
     buffer: ModelHandle<language::Buffer>,
     buffer_epoch: u64,
     client: Arc<Client>,
     subscription: Option<client::Subscription>,
+    acknowledge_task: Option<Task<Result<()>>>,
 }
 
 pub enum ChannelBufferEvent {
     CollaboratorsChanged,
     Disconnected,
+    BufferEdited,
 }
 
 impl Entity for ChannelBuffer {
@@ -33,6 +41,9 @@ impl Entity for ChannelBuffer {
 
     fn release(&mut self, _: &mut AppContext) {
         if self.connected {
+            if let Some(task) = self.acknowledge_task.take() {
+                task.detach();
+            }
             self.client
                 .send(proto::LeaveChannelBuffer {
                     channel_id: self.channel.id,
@@ -46,6 +57,7 @@ impl ChannelBuffer {
     pub(crate) async fn new(
         channel: Arc<Channel>,
         client: Arc<Client>,
+        user_store: ModelHandle<UserStore>,
         mut cx: AsyncAppContext,
     ) -> Result<ModelHandle<Self>> {
         let response = client
@@ -61,8 +73,6 @@ impl ChannelBuffer {
             .map(language::proto::deserialize_operation)
             .collect::<Result<Vec<_>, _>>()?;
 
-        let collaborators = response.collaborators;
-
         let buffer = cx.add_model(|_| {
             language::Buffer::remote(response.buffer_id, response.replica_id as u16, base_text)
         });
@@ -73,34 +83,46 @@ impl ChannelBuffer {
         anyhow::Ok(cx.add_model(|cx| {
             cx.subscribe(&buffer, Self::on_buffer_update).detach();
 
-            Self {
+            let mut this = Self {
                 buffer,
                 buffer_epoch: response.epoch,
                 client,
                 connected: true,
-                collaborators,
+                collaborators: Default::default(),
+                acknowledge_task: None,
                 channel,
                 subscription: Some(subscription.set_model(&cx.handle(), &mut cx.to_async())),
-            }
+                user_store,
+            };
+            this.replace_collaborators(response.collaborators, cx);
+            this
         }))
     }
 
+    pub fn user_store(&self) -> &ModelHandle<UserStore> {
+        &self.user_store
+    }
+
     pub(crate) fn replace_collaborators(
         &mut self,
         collaborators: Vec<proto::Collaborator>,
         cx: &mut ModelContext<Self>,
     ) {
-        for old_collaborator in &self.collaborators {
-            if collaborators
-                .iter()
-                .any(|c| c.replica_id == old_collaborator.replica_id)
-            {
+        let mut new_collaborators = HashMap::default();
+        for collaborator in collaborators {
+            if let Ok(collaborator) = Collaborator::from_proto(collaborator) {
+                new_collaborators.insert(collaborator.peer_id, collaborator);
+            }
+        }
+
+        for (_, old_collaborator) in &self.collaborators {
+            if !new_collaborators.contains_key(&old_collaborator.peer_id) {
                 self.buffer.update(cx, |buffer, cx| {
                     buffer.remove_peer(old_collaborator.replica_id as u16, cx)
                 });
             }
         }
-        self.collaborators = collaborators;
+        self.collaborators = new_collaborators;
         cx.emit(ChannelBufferEvent::CollaboratorsChanged);
         cx.notify();
     }
@@ -127,64 +149,14 @@ impl ChannelBuffer {
         Ok(())
     }
 
-    async fn handle_add_channel_buffer_collaborator(
+    async fn handle_update_channel_buffer_collaborators(
         this: ModelHandle<Self>,
-        envelope: TypedEnvelope<proto::AddChannelBufferCollaborator>,
-        _: Arc<Client>,
-        mut cx: AsyncAppContext,
-    ) -> Result<()> {
-        let collaborator = envelope.payload.collaborator.ok_or_else(|| {
-            anyhow::anyhow!(
-                "Should have gotten a collaborator in the AddChannelBufferCollaborator message"
-            )
-        })?;
-
-        this.update(&mut cx, |this, cx| {
-            this.collaborators.push(collaborator);
-            cx.emit(ChannelBufferEvent::CollaboratorsChanged);
-            cx.notify();
-        });
-
-        Ok(())
-    }
-
-    async fn handle_remove_channel_buffer_collaborator(
-        this: ModelHandle<Self>,
-        message: TypedEnvelope<proto::RemoveChannelBufferCollaborator>,
+        message: TypedEnvelope<proto::UpdateChannelBufferCollaborators>,
         _: Arc<Client>,
         mut cx: AsyncAppContext,
     ) -> Result<()> {
         this.update(&mut cx, |this, cx| {
-            this.collaborators.retain(|collaborator| {
-                if collaborator.peer_id == message.payload.peer_id {
-                    this.buffer.update(cx, |buffer, cx| {
-                        buffer.remove_peer(collaborator.replica_id as u16, cx)
-                    });
-                    false
-                } else {
-                    true
-                }
-            });
-            cx.emit(ChannelBufferEvent::CollaboratorsChanged);
-            cx.notify();
-        });
-
-        Ok(())
-    }
-
-    async fn handle_update_channel_buffer_collaborator(
-        this: ModelHandle<Self>,
-        message: TypedEnvelope<proto::UpdateChannelBufferCollaborator>,
-        _: Arc<Client>,
-        mut cx: AsyncAppContext,
-    ) -> Result<()> {
-        this.update(&mut cx, |this, cx| {
-            for collaborator in &mut this.collaborators {
-                if collaborator.peer_id == message.payload.old_peer_id {
-                    collaborator.peer_id = message.payload.new_peer_id;
-                    break;
-                }
-            }
+            this.replace_collaborators(message.payload.collaborators, cx);
             cx.emit(ChannelBufferEvent::CollaboratorsChanged);
             cx.notify();
         });
@@ -196,19 +168,45 @@ impl ChannelBuffer {
         &mut self,
         _: ModelHandle<language::Buffer>,
         event: &language::Event,
-        _: &mut ModelContext<Self>,
+        cx: &mut ModelContext<Self>,
     ) {
-        if let language::Event::Operation(operation) = event {
-            let operation = language::proto::serialize_operation(operation);
-            self.client
-                .send(proto::UpdateChannelBuffer {
-                    channel_id: self.channel.id,
-                    operations: vec![operation],
-                })
-                .log_err();
+        match event {
+            language::Event::Operation(operation) => {
+                let operation = language::proto::serialize_operation(operation);
+                self.client
+                    .send(proto::UpdateChannelBuffer {
+                        channel_id: self.channel.id,
+                        operations: vec![operation],
+                    })
+                    .log_err();
+            }
+            language::Event::Edited => {
+                cx.emit(ChannelBufferEvent::BufferEdited);
+            }
+            _ => {}
         }
     }
 
+    pub fn acknowledge_buffer_version(&mut self, cx: &mut ModelContext<'_, ChannelBuffer>) {
+        let buffer = self.buffer.read(cx);
+        let version = buffer.version();
+        let buffer_id = buffer.remote_id();
+        let client = self.client.clone();
+        let epoch = self.epoch();
+
+        self.acknowledge_task = Some(cx.spawn_weak(|_, cx| async move {
+            cx.background().timer(ACKNOWLEDGE_DEBOUNCE_INTERVAL).await;
+            client
+                .send(proto::AckBufferOperation {
+                    buffer_id,
+                    epoch,
+                    version: serialize_version(&version),
+                })
+                .ok();
+            Ok(())
+        }));
+    }
+
     pub fn epoch(&self) -> u64 {
         self.buffer_epoch
     }
@@ -217,7 +215,7 @@ impl ChannelBuffer {
         self.buffer.clone()
     }
 
-    pub fn collaborators(&self) -> &[proto::Collaborator] {
+    pub fn collaborators(&self) -> &HashMap<PeerId, Collaborator> {
         &self.collaborators
     }
 

crates/channel/src/channel_chat.rs

@@ -1,4 +1,4 @@
-use crate::Channel;
+use crate::{Channel, ChannelId, ChannelStore};
 use anyhow::{anyhow, Result};
 use client::{
     proto,
@@ -16,7 +16,9 @@ use util::{post_inc, ResultExt as _, TryFutureExt};
 pub struct ChannelChat {
     channel: Arc<Channel>,
     messages: SumTree<ChannelMessage>,
+    channel_store: ModelHandle<ChannelStore>,
     loaded_all_messages: bool,
+    last_acknowledged_id: Option<u64>,
     next_pending_message_id: usize,
     user_store: ModelHandle<UserStore>,
     rpc: Arc<Client>,
@@ -34,7 +36,7 @@ pub struct ChannelMessage {
     pub nonce: u128,
 }
 
-#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
+#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub enum ChannelMessageId {
     Saved(u64),
     Pending(usize),
@@ -55,6 +57,10 @@ pub enum ChannelChatEvent {
         old_range: Range<usize>,
         new_count: usize,
     },
+    NewMessage {
+        channel_id: ChannelId,
+        message_id: u64,
+    },
 }
 
 pub fn init(client: &Arc<Client>) {
@@ -77,6 +83,7 @@ impl Entity for ChannelChat {
 impl ChannelChat {
     pub async fn new(
         channel: Arc<Channel>,
+        channel_store: ModelHandle<ChannelStore>,
         user_store: ModelHandle<UserStore>,
         client: Arc<Client>,
         mut cx: AsyncAppContext,
@@ -94,11 +101,13 @@ impl ChannelChat {
             let mut this = Self {
                 channel,
                 user_store,
+                channel_store,
                 rpc: client,
                 outgoing_messages_lock: Default::default(),
                 messages: Default::default(),
                 loaded_all_messages,
                 next_pending_message_id: 0,
+                last_acknowledged_id: None,
                 rng: StdRng::from_entropy(),
                 _subscription: subscription.set_model(&cx.handle(), &mut cx.to_async()),
             };
@@ -219,6 +228,26 @@ impl ChannelChat {
         false
     }
 
+    pub fn acknowledge_last_message(&mut self, cx: &mut ModelContext<Self>) {
+        if let ChannelMessageId::Saved(latest_message_id) = self.messages.summary().max_id {
+            if self
+                .last_acknowledged_id
+                .map_or(true, |acknowledged_id| acknowledged_id < latest_message_id)
+            {
+                self.rpc
+                    .send(proto::AckChannelMessage {
+                        channel_id: self.channel.id,
+                        message_id: latest_message_id,
+                    })
+                    .ok();
+                self.last_acknowledged_id = Some(latest_message_id);
+                self.channel_store.update(cx, |store, cx| {
+                    store.acknowledge_message_id(self.channel.id, latest_message_id, cx);
+                });
+            }
+        }
+    }
+
     pub fn rejoin(&mut self, cx: &mut ModelContext<Self>) {
         let user_store = self.user_store.clone();
         let rpc = self.rpc.clone();
@@ -313,10 +342,15 @@ impl ChannelChat {
             .payload
             .message
             .ok_or_else(|| anyhow!("empty message"))?;
+        let message_id = message.id;
 
         let message = ChannelMessage::from_proto(message, &user_store, &mut cx).await?;
         this.update(&mut cx, |this, cx| {
-            this.insert_messages(SumTree::from_item(message, &()), cx)
+            this.insert_messages(SumTree::from_item(message, &()), cx);
+            cx.emit(ChannelChatEvent::NewMessage {
+                channel_id: this.channel.id,
+                message_id,
+            })
         });
 
         Ok(())
@@ -388,6 +422,7 @@ impl ChannelChat {
                 old_range: start_ix..end_ix,
                 new_count,
             });
+
             cx.notify();
         }
     }

crates/channel/src/channel_store.rs

@@ -43,6 +43,8 @@ pub type ChannelData = (Channel, ChannelPath);
 pub struct Channel {
     pub id: ChannelId,
     pub name: String,
+    pub unseen_note_version: Option<(u64, clock::Global)>,
+    pub unseen_message_id: Option<u64>,
 }
 
 #[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Clone, Serialize, Deserialize)]
@@ -198,14 +200,73 @@ impl ChannelStore {
         cx: &mut ModelContext<Self>,
     ) -> Task<Result<ModelHandle<ChannelBuffer>>> {
         let client = self.client.clone();
+        let user_store = self.user_store.clone();
         self.open_channel_resource(
             channel_id,
             |this| &mut this.opened_buffers,
-            |channel, cx| ChannelBuffer::new(channel, client, cx),
+            |channel, cx| ChannelBuffer::new(channel, client, user_store, cx),
             cx,
         )
     }
 
+    pub fn has_channel_buffer_changed(&self, channel_id: ChannelId) -> Option<bool> {
+        self.channel_index
+            .by_id()
+            .get(&channel_id)
+            .map(|channel| channel.unseen_note_version.is_some())
+    }
+
+    pub fn has_new_messages(&self, channel_id: ChannelId) -> Option<bool> {
+        self.channel_index
+            .by_id()
+            .get(&channel_id)
+            .map(|channel| channel.unseen_message_id.is_some())
+    }
+
+    pub fn notes_changed(
+        &mut self,
+        channel_id: ChannelId,
+        epoch: u64,
+        version: &clock::Global,
+        cx: &mut ModelContext<Self>,
+    ) {
+        self.channel_index.note_changed(channel_id, epoch, version);
+        cx.notify();
+    }
+
+    pub fn new_message(
+        &mut self,
+        channel_id: ChannelId,
+        message_id: u64,
+        cx: &mut ModelContext<Self>,
+    ) {
+        self.channel_index.new_message(channel_id, message_id);
+        cx.notify();
+    }
+
+    pub fn acknowledge_message_id(
+        &mut self,
+        channel_id: ChannelId,
+        message_id: u64,
+        cx: &mut ModelContext<Self>,
+    ) {
+        self.channel_index
+            .acknowledge_message_id(channel_id, message_id);
+        cx.notify();
+    }
+
+    pub fn acknowledge_notes_version(
+        &mut self,
+        channel_id: ChannelId,
+        epoch: u64,
+        version: &clock::Global,
+        cx: &mut ModelContext<Self>,
+    ) {
+        self.channel_index
+            .acknowledge_note_version(channel_id, epoch, version);
+        cx.notify();
+    }
+
     pub fn open_channel_chat(
         &mut self,
         channel_id: ChannelId,
@@ -213,10 +274,11 @@ impl ChannelStore {
     ) -> Task<Result<ModelHandle<ChannelChat>>> {
         let client = self.client.clone();
         let user_store = self.user_store.clone();
+        let this = cx.handle();
         self.open_channel_resource(
             channel_id,
             |this| &mut this.opened_chats,
-            |channel, cx| ChannelChat::new(channel, user_store, client, cx),
+            |channel, cx| ChannelChat::new(channel, this, user_store, client, cx),
             cx,
         )
     }
@@ -778,6 +840,8 @@ impl ChannelStore {
                     Arc::new(Channel {
                         id: channel.id,
                         name: channel.name,
+                        unseen_note_version: None,
+                        unseen_message_id: None,
                     }),
                 ),
             }
@@ -786,7 +850,9 @@ impl ChannelStore {
         let channels_changed = !payload.channels.is_empty()
             || !payload.delete_channels.is_empty()
             || !payload.insert_edge.is_empty()
-            || !payload.delete_edge.is_empty();
+            || !payload.delete_edge.is_empty()
+            || !payload.unseen_channel_messages.is_empty()
+            || !payload.unseen_channel_buffer_changes.is_empty();
 
         if channels_changed {
             if !payload.delete_channels.is_empty() {
@@ -813,6 +879,22 @@ impl ChannelStore {
                 index.insert(channel)
             }
 
+            for unseen_buffer_change in payload.unseen_channel_buffer_changes {
+                let version = language::proto::deserialize_version(&unseen_buffer_change.version);
+                index.note_changed(
+                    unseen_buffer_change.channel_id,
+                    unseen_buffer_change.epoch,
+                    &version,
+                );
+            }
+
+            for unseen_channel_message in payload.unseen_channel_messages {
+                index.new_messages(
+                    unseen_channel_message.channel_id,
+                    unseen_channel_message.message_id,
+                );
+            }
+
             for edge in payload.insert_edge {
                 index.insert_edge(edge.channel_id, edge.parent_id);
             }

crates/channel/src/channel_store/channel_index.rs

@@ -38,6 +38,43 @@ impl ChannelIndex {
             channels_by_id: &mut self.channels_by_id,
         }
     }
+
+    pub fn acknowledge_note_version(
+        &mut self,
+        channel_id: ChannelId,
+        epoch: u64,
+        version: &clock::Global,
+    ) {
+        if let Some(channel) = self.channels_by_id.get_mut(&channel_id) {
+            let channel = Arc::make_mut(channel);
+            if let Some((unseen_epoch, unseen_version)) = &channel.unseen_note_version {
+                if epoch > *unseen_epoch
+                    || epoch == *unseen_epoch && version.observed_all(unseen_version)
+                {
+                    channel.unseen_note_version = None;
+                }
+            }
+        }
+    }
+
+    pub fn acknowledge_message_id(&mut self, channel_id: ChannelId, message_id: u64) {
+        if let Some(channel) = self.channels_by_id.get_mut(&channel_id) {
+            let channel = Arc::make_mut(channel);
+            if let Some(unseen_message_id) = channel.unseen_message_id {
+                if message_id >= unseen_message_id {
+                    channel.unseen_message_id = None;
+                }
+            }
+        }
+    }
+
+    pub fn note_changed(&mut self, channel_id: ChannelId, epoch: u64, version: &clock::Global) {
+        insert_note_changed(&mut self.channels_by_id, channel_id, epoch, version);
+    }
+
+    pub fn new_message(&mut self, channel_id: ChannelId, message_id: u64) {
+        insert_new_message(&mut self.channels_by_id, channel_id, message_id)
+    }
 }
 
 impl Deref for ChannelIndex {
@@ -76,6 +113,14 @@ impl<'a> ChannelPathsInsertGuard<'a> {
         }
     }
 
+    pub fn note_changed(&mut self, channel_id: ChannelId, epoch: u64, version: &clock::Global) {
+        insert_note_changed(&mut self.channels_by_id, channel_id, epoch, &version);
+    }
+
+    pub fn new_messages(&mut self, channel_id: ChannelId, message_id: u64) {
+        insert_new_message(&mut self.channels_by_id, channel_id, message_id)
+    }
+
     pub fn insert(&mut self, channel_proto: proto::Channel) {
         if let Some(existing_channel) = self.channels_by_id.get_mut(&channel_proto.id) {
             Arc::make_mut(existing_channel).name = channel_proto.name;
@@ -85,6 +130,8 @@ impl<'a> ChannelPathsInsertGuard<'a> {
                 Arc::new(Channel {
                     id: channel_proto.id,
                     name: channel_proto.name,
+                    unseen_note_version: None,
+                    unseen_message_id: None,
                 }),
             );
             self.insert_root(channel_proto.id);
@@ -160,3 +207,32 @@ fn channel_path_sorting_key<'a>(
     path.iter()
         .map(|id| Some(channels_by_id.get(id)?.name.as_str()))
 }
+
+fn insert_note_changed(
+    channels_by_id: &mut BTreeMap<ChannelId, Arc<Channel>>,
+    channel_id: u64,
+    epoch: u64,
+    version: &clock::Global,
+) {
+    if let Some(channel) = channels_by_id.get_mut(&channel_id) {
+        let unseen_version = Arc::make_mut(channel)
+            .unseen_note_version
+            .get_or_insert((0, clock::Global::new()));
+        if epoch > unseen_version.0 {
+            *unseen_version = (epoch, version.clone());
+        } else {
+            unseen_version.1.join(&version);
+        }
+    }
+}
+
+fn insert_new_message(
+    channels_by_id: &mut BTreeMap<ChannelId, Arc<Channel>>,
+    channel_id: u64,
+    message_id: u64,
+) {
+    if let Some(channel) = channels_by_id.get_mut(&channel_id) {
+        let unseen_message_id = Arc::make_mut(channel).unseen_message_id.get_or_insert(0);
+        *unseen_message_id = message_id.max(*unseen_message_id);
+    }
+}

crates/client/Cargo.toml

@@ -33,15 +33,16 @@ parking_lot.workspace = true
 postage.workspace = true
 rand.workspace = true
 schemars.workspace = true
+serde.workspace = true
+serde_derive.workspace = true
 smol.workspace = true
+sysinfo.workspace = true
+tempfile = "3"
 thiserror.workspace = true
 time.workspace = true
 tiny_http = "0.8"
-uuid = { version = "1.1.2", features = ["v4"] }
+uuid.workspace = true
 url = "2.2"
-serde.workspace = true
-serde_derive.workspace = true
-tempfile = "3"
 
 [dev-dependencies]
 collections = { path = "../collections", features = ["test-support"] }

crates/client/src/client.rs

@@ -34,7 +34,7 @@ use std::{
     future::Future,
     marker::PhantomData,
     path::PathBuf,
-    sync::{Arc, Weak},
+    sync::{atomic::AtomicU64, Arc, Weak},
     time::{Duration, Instant},
 };
 use telemetry::Telemetry;
@@ -62,13 +62,15 @@ lazy_static! {
         .and_then(|v| v.parse().ok());
     pub static ref ZED_APP_PATH: Option<PathBuf> =
         std::env::var("ZED_APP_PATH").ok().map(PathBuf::from);
+    pub static ref ZED_ALWAYS_ACTIVE: bool =
+        std::env::var("ZED_ALWAYS_ACTIVE").map_or(false, |e| e.len() > 0);
 }
 
 pub const ZED_SECRET_CLIENT_TOKEN: &str = "618033988749894";
 pub const INITIAL_RECONNECTION_DELAY: Duration = Duration::from_millis(100);
 pub const CONNECTION_TIMEOUT: Duration = Duration::from_secs(5);
 
-actions!(client, [SignIn, SignOut]);
+actions!(client, [SignIn, SignOut, Reconnect]);
 
 pub fn init_settings(cx: &mut AppContext) {
     settings::register::<TelemetrySettings>(cx);
@@ -100,10 +102,21 @@ pub fn init(client: &Arc<Client>, cx: &mut AppContext) {
             }
         }
     });
+    cx.add_global_action({
+        let client = client.clone();
+        move |_: &Reconnect, cx| {
+            if let Some(client) = client.upgrade() {
+                cx.spawn(|cx| async move {
+                    client.reconnect(&cx);
+                })
+                .detach();
+            }
+        }
+    });
 }
 
 pub struct Client {
-    id: usize,
+    id: AtomicU64,
     peer: Arc<Peer>,
     http: Arc<dyn HttpClient>,
     telemetry: Arc<Telemetry>,
@@ -372,7 +385,7 @@ impl settings::Setting for TelemetrySettings {
 impl Client {
     pub fn new(http: Arc<dyn HttpClient>, cx: &AppContext) -> Arc<Self> {
         Arc::new(Self {
-            id: 0,
+            id: AtomicU64::new(0),
             peer: Peer::new(0),
             telemetry: Telemetry::new(http.clone(), cx),
             http,
@@ -385,17 +398,16 @@ impl Client {
         })
     }
 
-    pub fn id(&self) -> usize {
-        self.id
+    pub fn id(&self) -> u64 {
+        self.id.load(std::sync::atomic::Ordering::SeqCst)
     }
 
     pub fn http_client(&self) -> Arc<dyn HttpClient> {
         self.http.clone()
     }
 
-    #[cfg(any(test, feature = "test-support"))]
-    pub fn set_id(&mut self, id: usize) -> &Self {
-        self.id = id;
+    pub fn set_id(&self, id: u64) -> &Self {
+        self.id.store(id, std::sync::atomic::Ordering::SeqCst);
         self
     }
 
@@ -452,7 +464,7 @@ impl Client {
     }
 
     fn set_status(self: &Arc<Self>, status: Status, cx: &AsyncAppContext) {
-        log::info!("set status on client {}: {:?}", self.id, status);
+        log::info!("set status on client {}: {:?}", self.id(), status);
         let mut state = self.state.write();
         *state.status.0.borrow_mut() = status;
 
@@ -803,6 +815,7 @@ impl Client {
             }
         }
         let credentials = credentials.unwrap();
+        self.set_id(credentials.user_id);
 
         if was_disconnected {
             self.set_status(Status::Connecting, cx);
@@ -1210,6 +1223,11 @@ impl Client {
         self.set_status(Status::SignedOut, cx);
     }
 
+    pub fn reconnect(self: &Arc<Self>, cx: &AsyncAppContext) {
+        self.peer.teardown();
+        self.set_status(Status::ConnectionLost, cx);
+    }
+
     fn connection_id(&self) -> Result<ConnectionId> {
         if let Status::Connected { connection_id, .. } = *self.status().borrow() {
             Ok(connection_id)
@@ -1219,7 +1237,7 @@ impl Client {
     }
 
     pub fn send<T: EnvelopedMessage>(&self, message: T) -> Result<()> {
-        log::debug!("rpc send. client_id:{}, name:{}", self.id, T::NAME);
+        log::debug!("rpc send. client_id:{}, name:{}", self.id(), T::NAME);
         self.peer.send(self.connection_id()?, message)
     }
 
@@ -1235,7 +1253,7 @@ impl Client {
         &self,
         request: T,
     ) -> impl Future<Output = Result<TypedEnvelope<T::Response>>> {
-        let client_id = self.id;
+        let client_id = self.id();
         log::debug!(
             "rpc request start. client_id:{}. name:{}",
             client_id,
@@ -1256,7 +1274,7 @@ impl Client {
     }
 
     fn respond<T: RequestMessage>(&self, receipt: Receipt<T>, response: T::Response) -> Result<()> {
-        log::debug!("rpc respond. client_id:{}. name:{}", self.id, T::NAME);
+        log::debug!("rpc respond. client_id:{}. name:{}", self.id(), T::NAME);
         self.peer.respond(receipt, response)
     }
 
@@ -1265,7 +1283,7 @@ impl Client {
         receipt: Receipt<T>,
         error: proto::Error,
     ) -> Result<()> {
-        log::debug!("rpc respond. client_id:{}. name:{}", self.id, T::NAME);
+        log::debug!("rpc respond. client_id:{}. name:{}", self.id(), T::NAME);
         self.peer.respond_with_error(receipt, error)
     }
 
@@ -1334,7 +1352,7 @@ impl Client {
 
         if let Some(handler) = handler {
             let future = handler(subscriber, message, &self, cx.clone());
-            let client_id = self.id;
+            let client_id = self.id();
             log::debug!(
                 "rpc message received. client_id:{}, sender_id:{:?}, type:{}",
                 client_id,

crates/client/src/telemetry.rs

@@ -4,6 +4,7 @@ use lazy_static::lazy_static;
 use parking_lot::Mutex;
 use serde::Serialize;
 use std::{env, io::Write, mem, path::PathBuf, sync::Arc, time::Duration};
+use sysinfo::{Pid, PidExt, ProcessExt, System, SystemExt};
 use tempfile::NamedTempFile;
 use util::http::HttpClient;
 use util::{channel::ReleaseChannel, TryFutureExt};
@@ -17,7 +18,8 @@ pub struct Telemetry {
 #[derive(Default)]
 struct TelemetryState {
     metrics_id: Option<Arc<str>>,      // Per logged-in user
-    installation_id: Option<Arc<str>>, // Per app installation
+    installation_id: Option<Arc<str>>, // Per app installation (different for dev, preview, and stable)
+    session_id: Option<Arc<str>>,      // Per app launch
     app_version: Option<Arc<str>>,
     release_channel: Option<&'static str>,
     os_name: &'static str,
@@ -40,6 +42,7 @@ lazy_static! {
 struct ClickhouseEventRequestBody {
     token: &'static str,
     installation_id: Option<Arc<str>>,
+    session_id: Option<Arc<str>>,
     is_staff: Option<bool>,
     app_version: Option<Arc<str>>,
     os_name: &'static str,
@@ -88,6 +91,14 @@ pub enum ClickhouseEvent {
         kind: AssistantKind,
         model: &'static str,
     },
+    Cpu {
+        usage_as_percentage: f32,
+        core_count: u32,
+    },
+    Memory {
+        memory_in_bytes: u64,
+        virtual_memory_in_bytes: u64,
+    },
 }
 
 #[cfg(debug_assertions)]
@@ -122,6 +133,7 @@ impl Telemetry {
                 release_channel,
                 installation_id: None,
                 metrics_id: None,
+                session_id: None,
                 clickhouse_events_queue: Default::default(),
                 flush_clickhouse_events_task: Default::default(),
                 log_file: None,
@@ -136,15 +148,61 @@ impl Telemetry {
         Some(self.state.lock().log_file.as_ref()?.path().to_path_buf())
     }
 
-    pub fn start(self: &Arc<Self>, installation_id: Option<String>) {
+    pub fn start(
+        self: &Arc<Self>,
+        installation_id: Option<String>,
+        session_id: String,
+        cx: &mut AppContext,
+    ) {
         let mut state = self.state.lock();
         state.installation_id = installation_id.map(|id| id.into());
+        state.session_id = Some(session_id.into());
         let has_clickhouse_events = !state.clickhouse_events_queue.is_empty();
         drop(state);
 
         if has_clickhouse_events {
             self.flush_clickhouse_events();
         }
+
+        let this = self.clone();
+        cx.spawn(|mut cx| async move {
+            let mut system = System::new_all();
+            system.refresh_all();
+
+            loop {
+                // Waiting some amount of time before the first query is important to get a reasonable value
+                // https://docs.rs/sysinfo/0.29.10/sysinfo/trait.ProcessExt.html#tymethod.cpu_usage
+                const DURATION_BETWEEN_SYSTEM_EVENTS: Duration = Duration::from_secs(60);
+                smol::Timer::after(DURATION_BETWEEN_SYSTEM_EVENTS).await;
+
+                system.refresh_memory();
+                system.refresh_processes();
+
+                let current_process = Pid::from_u32(std::process::id());
+                let Some(process) = system.processes().get(&current_process) else {
+                    let process = current_process;
+                    log::error!("Failed to find own process {process:?} in system process table");
+                    // TODO: Fire an error telemetry event
+                    return;
+                };
+
+                let memory_event = ClickhouseEvent::Memory {
+                    memory_in_bytes: process.memory(),
+                    virtual_memory_in_bytes: process.virtual_memory(),
+                };
+
+                let cpu_event = ClickhouseEvent::Cpu {
+                    usage_as_percentage: process.cpu_usage(),
+                    core_count: system.cpus().len() as u32,
+                };
+
+                let telemetry_settings = cx.update(|cx| *settings::get::<TelemetrySettings>(cx));
+
+                this.report_clickhouse_event(memory_event, telemetry_settings);
+                this.report_clickhouse_event(cpu_event, telemetry_settings);
+            }
+        })
+        .detach();
     }
 
     pub fn set_authenticated_user_info(
@@ -230,22 +288,21 @@ impl Telemetry {
 
                     {
                         let state = this.state.lock();
-                        json_bytes.clear();
-                        serde_json::to_writer(
-                            &mut json_bytes,
-                            &ClickhouseEventRequestBody {
-                                token: ZED_SECRET_CLIENT_TOKEN,
-                                installation_id: state.installation_id.clone(),
-                                is_staff: state.is_staff.clone(),
-                                app_version: state.app_version.clone(),
-                                os_name: state.os_name,
-                                os_version: state.os_version.clone(),
-                                architecture: state.architecture,
+                        let request_body = ClickhouseEventRequestBody {
+                            token: ZED_SECRET_CLIENT_TOKEN,
+                            installation_id: state.installation_id.clone(),
+                            session_id: state.session_id.clone(),
+                            is_staff: state.is_staff.clone(),
+                            app_version: state.app_version.clone(),
+                            os_name: state.os_name,
+                            os_version: state.os_version.clone(),
+                            architecture: state.architecture,
 
-                                release_channel: state.release_channel,
-                                events,
-                            },
-                        )?;
+                            release_channel: state.release_channel,
+                            events,
+                        };
+                        json_bytes.clear();
+                        serde_json::to_writer(&mut json_bytes, &request_body)?;
                     }
 
                     this.http_client

crates/client/src/user.rs

@@ -7,11 +7,15 @@ use gpui::{AsyncAppContext, Entity, ImageData, ModelContext, ModelHandle, Task};
 use postage::{sink::Sink, watch};
 use rpc::proto::{RequestMessage, UsersResponse};
 use std::sync::{Arc, Weak};
+use text::ReplicaId;
 use util::http::HttpClient;
 use util::TryFutureExt as _;
 
 pub type UserId = u64;
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct ParticipantIndex(pub u32);
+
 #[derive(Default, Debug)]
 pub struct User {
     pub id: UserId,
@@ -19,6 +23,13 @@ pub struct User {
     pub avatar: Option<Arc<ImageData>>,
 }
 
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct Collaborator {
+    pub peer_id: proto::PeerId,
+    pub replica_id: ReplicaId,
+    pub user_id: UserId,
+}
+
 impl PartialOrd for User {
     fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
         Some(self.cmp(other))
@@ -56,6 +67,7 @@ pub enum ContactRequestStatus {
 
 pub struct UserStore {
     users: HashMap<u64, Arc<User>>,
+    participant_indices: HashMap<u64, ParticipantIndex>,
     update_contacts_tx: mpsc::UnboundedSender<UpdateContacts>,
     current_user: watch::Receiver<Option<Arc<User>>>,
     contacts: Vec<Arc<Contact>>,
@@ -81,6 +93,7 @@ pub enum Event {
         kind: ContactEventKind,
     },
     ShowContacts,
+    ParticipantIndicesChanged,
 }
 
 #[derive(Clone, Copy)]
@@ -118,6 +131,7 @@ impl UserStore {
             current_user: current_user_rx,
             contacts: Default::default(),
             incoming_contact_requests: Default::default(),
+            participant_indices: Default::default(),
             outgoing_contact_requests: Default::default(),
             invite_info: None,
             client: Arc::downgrade(&client),
@@ -581,6 +595,10 @@ impl UserStore {
         self.load_users(proto::FuzzySearchUsers { query }, cx)
     }
 
+    pub fn get_cached_user(&self, user_id: u64) -> Option<Arc<User>> {
+        self.users.get(&user_id).cloned()
+    }
+
     pub fn get_user(
         &mut self,
         user_id: u64,
@@ -641,6 +659,21 @@ impl UserStore {
             }
         })
     }
+
+    pub fn set_participant_indices(
+        &mut self,
+        participant_indices: HashMap<u64, ParticipantIndex>,
+        cx: &mut ModelContext<Self>,
+    ) {
+        if participant_indices != self.participant_indices {
+            self.participant_indices = participant_indices;
+            cx.emit(Event::ParticipantIndicesChanged);
+        }
+    }
+
+    pub fn participant_indices(&self) -> &HashMap<u64, ParticipantIndex> {
+        &self.participant_indices
+    }
 }
 
 impl User {
@@ -672,6 +705,16 @@ impl Contact {
     }
 }
 
+impl Collaborator {
+    pub fn from_proto(message: proto::Collaborator) -> Result<Self> {
+        Ok(Self {
+            peer_id: message.peer_id.ok_or_else(|| anyhow!("invalid peer id"))?,
+            replica_id: message.replica_id as ReplicaId,
+            user_id: message.user_id as UserId,
+        })
+    }
+}
+
 async fn fetch_avatar(http: &dyn HttpClient, url: &str) -> Result<Arc<ImageData>> {
     let mut response = http
         .get(url, Default::default(), true)

crates/collab/Cargo.toml

@@ -3,7 +3,7 @@ authors = ["Nathan Sobo <nathan@zed.dev>"]
 default-run = "collab"
 edition = "2021"
 name = "collab"
-version = "0.21.0"
+version = "0.22.2"
 publish = false
 
 [[bin]]
@@ -42,14 +42,12 @@ rand.workspace = true
 reqwest = { version = "0.11", features = ["json"], optional = true }
 scrypt = "0.7"
 smallvec.workspace = true
-# Remove fork dependency when a version with https://github.com/SeaQL/sea-orm/pull/1283 is released.
-sea-orm = { git = "https://github.com/zed-industries/sea-orm", rev = "18f4c691085712ad014a51792af75a9044bacee6", features = ["sqlx-postgres", "postgres-array", "runtime-tokio-rustls"] }
-sea-query = "0.27"
+sea-orm = { version = "0.12.x", features = ["sqlx-postgres", "postgres-array", "runtime-tokio-rustls", "with-uuid"] }
 serde.workspace = true
 serde_derive.workspace = true
 serde_json.workspace = true
 sha-1 = "0.9"
-sqlx = { version = "0.6", features = ["runtime-tokio-rustls", "postgres", "json", "time", "uuid", "any"] }
+sqlx = { version = "0.7", features = ["runtime-tokio-rustls", "postgres", "json", "time", "uuid", "any"] }
 time.workspace = true
 tokio = { version = "1", features = ["full"] }
 tokio-tungstenite = "0.17"
@@ -59,6 +57,7 @@ toml.workspace = true
 tracing = "0.1.34"
 tracing-log = "0.1.3"
 tracing-subscriber = { version = "0.3.11", features = ["env-filter", "json"] }
+uuid.workspace = true
 
 [dev-dependencies]
 audio = { path = "../audio" }
@@ -87,9 +86,9 @@ env_logger.workspace = true
 indoc.workspace = true
 util = { path = "../util" }
 lazy_static.workspace = true
-sea-orm = { git = "https://github.com/zed-industries/sea-orm", rev = "18f4c691085712ad014a51792af75a9044bacee6", features = ["sqlx-sqlite"] }
+sea-orm = { version = "0.12.x", features = ["sqlx-sqlite"] }
 serde_json.workspace = true
-sqlx = { version = "0.6", features = ["sqlite"] }
+sqlx = { version = "0.7", features = ["sqlite"] }
 unindent.workspace = true
 
 [features]

crates/collab/migrations.sqlite/20221109000000_test_schema.sql

@@ -158,7 +158,8 @@ CREATE TABLE "room_participants" (
     "initial_project_id" INTEGER,
     "calling_user_id" INTEGER NOT NULL REFERENCES users (id),
     "calling_connection_id" INTEGER NOT NULL,
-    "calling_connection_server_id" INTEGER REFERENCES servers (id) ON DELETE SET NULL
+    "calling_connection_server_id" INTEGER REFERENCES servers (id) ON DELETE SET NULL,
+    "participant_index" INTEGER
 );
 CREATE UNIQUE INDEX "index_room_participants_on_user_id" ON "room_participants" ("user_id");
 CREATE INDEX "index_room_participants_on_room_id" ON "room_participants" ("room_id");
@@ -288,3 +289,24 @@ CREATE TABLE "user_features" (
 CREATE UNIQUE INDEX "index_user_features_user_id_and_feature_id" ON "user_features" ("user_id", "feature_id");
 CREATE INDEX "index_user_features_on_user_id" ON "user_features" ("user_id");
 CREATE INDEX "index_user_features_on_feature_id" ON "user_features" ("feature_id");
+
+
+CREATE TABLE "observed_buffer_edits" (
+    "user_id" INTEGER NOT NULL REFERENCES users (id) ON DELETE CASCADE,
+    "buffer_id" INTEGER NOT NULL REFERENCES buffers (id) ON DELETE CASCADE,
+    "epoch" INTEGER NOT NULL,
+    "lamport_timestamp" INTEGER NOT NULL,
+    "replica_id" INTEGER NOT NULL,
+    PRIMARY KEY (user_id, buffer_id)
+);
+
+CREATE UNIQUE INDEX "index_observed_buffers_user_and_buffer_id" ON "observed_buffer_edits" ("user_id", "buffer_id");
+
+CREATE TABLE IF NOT EXISTS "observed_channel_messages" (
+    "user_id" INTEGER NOT NULL REFERENCES users (id) ON DELETE CASCADE,
+    "channel_id" INTEGER NOT NULL REFERENCES channels (id) ON DELETE CASCADE,
+    "channel_message_id" INTEGER NOT NULL,
+    PRIMARY KEY (user_id, channel_id)
+);
+
+CREATE UNIQUE INDEX "index_observed_channel_messages_user_and_channel_id" ON "observed_channel_messages" ("user_id", "channel_id");

crates/collab/migrations/20230925210437_add_channel_changes.sql

@@ -0,0 +1,19 @@
+CREATE TABLE IF NOT EXISTS "observed_buffer_edits" (
+    "user_id" INTEGER NOT NULL REFERENCES users (id) ON DELETE CASCADE,
+    "buffer_id" INTEGER NOT NULL REFERENCES buffers (id) ON DELETE CASCADE,
+    "epoch" INTEGER NOT NULL,
+    "lamport_timestamp" INTEGER NOT NULL,
+    "replica_id" INTEGER NOT NULL,
+    PRIMARY KEY (user_id, buffer_id)
+);
+
+CREATE UNIQUE INDEX "index_observed_buffer_user_and_buffer_id" ON "observed_buffer_edits" ("user_id", "buffer_id");
+
+CREATE TABLE IF NOT EXISTS "observed_channel_messages" (
+    "user_id" INTEGER NOT NULL REFERENCES users (id) ON DELETE CASCADE,
+    "channel_id" INTEGER NOT NULL REFERENCES channels (id) ON DELETE CASCADE,
+    "channel_message_id" INTEGER NOT NULL,
+    PRIMARY KEY (user_id, channel_id)
+);
+
+CREATE UNIQUE INDEX "index_observed_channel_messages_user_and_channel_id" ON "observed_channel_messages" ("user_id", "channel_id");

crates/collab/migrations/20230926102500_add_participant_index_to_room_participants.sql

@@ -0,0 +1 @@
+ALTER TABLE room_participants ADD COLUMN participant_index INTEGER;

crates/collab/src/db.rs

@@ -19,11 +19,12 @@ use rpc::{
     ConnectionId,
 };
 use sea_orm::{
-    entity::prelude::*, ActiveValue, Condition, ConnectionTrait, DatabaseConnection,
-    DatabaseTransaction, DbErr, FromQueryResult, IntoActiveModel, IsolationLevel, JoinType,
-    QueryOrder, QuerySelect, Statement, TransactionTrait,
+    entity::prelude::*,
+    sea_query::{Alias, Expr, OnConflict, Query},
+    ActiveValue, Condition, ConnectionTrait, DatabaseConnection, DatabaseTransaction, DbErr,
+    FromQueryResult, IntoActiveModel, IsolationLevel, JoinType, QueryOrder, QuerySelect, Statement,
+    TransactionTrait,
 };
-use sea_query::{Alias, Expr, OnConflict, Query};
 use serde::{Deserialize, Serialize};
 use sqlx::{
     migrate::{Migrate, Migration, MigrationSource},
@@ -62,6 +63,7 @@ pub struct Database {
 // separate files in the `queries` folder.
 impl Database {
     pub async fn new(options: ConnectOptions, executor: Executor) -> Result<Self> {
+        sqlx::any::install_default_drivers();
         Ok(Self {
             options: options.clone(),
             pool: sea_orm::Database::connect(options).await?,
@@ -119,7 +121,7 @@ impl Database {
         Ok(new_migrations)
     }
 
-    async fn transaction<F, Fut, T>(&self, f: F) -> Result<T>
+    pub async fn transaction<F, Fut, T>(&self, f: F) -> Result<T>
     where
         F: Send + Fn(TransactionHandle) -> Fut,
         Fut: Send + Future<Output = Result<T>>,
@@ -321,7 +323,7 @@ fn is_serialization_error(error: &Error) -> bool {
     }
 }
 
-struct TransactionHandle(Arc<Option<DatabaseTransaction>>);
+pub struct TransactionHandle(Arc<Option<DatabaseTransaction>>);
 
 impl Deref for TransactionHandle {
     type Target = DatabaseTransaction;
@@ -437,6 +439,8 @@ pub struct ChannelsForUser {
     pub channels: ChannelGraph,
     pub channel_participants: HashMap<ChannelId, Vec<UserId>>,
     pub channels_with_admin_privileges: HashSet<ChannelId>,
+    pub unseen_buffer_changes: Vec<proto::UnseenChannelBufferChange>,
+    pub channel_messages: Vec<proto::UnseenChannelMessage>,
 }
 
 #[derive(Debug)]
@@ -510,7 +514,7 @@ pub struct RefreshedRoom {
 
 pub struct RefreshedChannelBuffer {
     pub connection_ids: Vec<ConnectionId>,
-    pub removed_collaborators: Vec<proto::RemoveChannelBufferCollaborator>,
+    pub collaborators: Vec<proto::Collaborator>,
 }
 
 pub struct Project {

crates/collab/src/db/ids.rs

@@ -1,6 +1,5 @@
 use crate::Result;
-use sea_orm::DbErr;
-use sea_query::{Value, ValueTypeErr};
+use sea_orm::{entity::prelude::*, DbErr};
 use serde::{Deserialize, Serialize};
 
 macro_rules! id_type {
@@ -17,6 +16,7 @@ macro_rules! id_type {
             Hash,
             Serialize,
             Deserialize,
+            DeriveValueType,
         )]
         #[serde(transparent)]
         pub struct $name(pub i32);
@@ -42,40 +42,6 @@ macro_rules! id_type {
             }
         }
 
-        impl From<$name> for sea_query::Value {
-            fn from(value: $name) -> Self {
-                sea_query::Value::Int(Some(value.0))
-            }
-        }
-
-        impl sea_orm::TryGetable for $name {
-            fn try_get(
-                res: &sea_orm::QueryResult,
-                pre: &str,
-                col: &str,
-            ) -> Result<Self, sea_orm::TryGetError> {
-                Ok(Self(i32::try_get(res, pre, col)?))
-            }
-        }
-
-        impl sea_query::ValueType for $name {
-            fn try_from(v: Value) -> Result<Self, sea_query::ValueTypeErr> {
-                Ok(Self(value_to_integer(v)?))
-            }
-
-            fn type_name() -> String {
-                stringify!($name).into()
-            }
-
-            fn array_type() -> sea_query::ArrayType {
-                sea_query::ArrayType::Int
-            }
-
-            fn column_type() -> sea_query::ColumnType {
-                sea_query::ColumnType::Integer(None)
-            }
-        }
-
         impl sea_orm::TryFromU64 for $name {
             fn try_from_u64(n: u64) -> Result<Self, DbErr> {
                 Ok(Self(n.try_into().map_err(|_| {
@@ -88,7 +54,7 @@ macro_rules! id_type {
             }
         }
 
-        impl sea_query::Nullable for $name {
+        impl sea_orm::sea_query::Nullable for $name {
             fn null() -> Value {
                 Value::Int(None)
             }
@@ -96,20 +62,6 @@ macro_rules! id_type {
     };
 }
 
-fn value_to_integer(v: Value) -> Result<i32, ValueTypeErr> {
-    match v {
-        Value::TinyInt(Some(int)) => int.try_into().map_err(|_| ValueTypeErr),
-        Value::SmallInt(Some(int)) => int.try_into().map_err(|_| ValueTypeErr),
-        Value::Int(Some(int)) => int.try_into().map_err(|_| ValueTypeErr),
-        Value::BigInt(Some(int)) => int.try_into().map_err(|_| ValueTypeErr),
-        Value::TinyUnsigned(Some(int)) => int.try_into().map_err(|_| ValueTypeErr),
-        Value::SmallUnsigned(Some(int)) => int.try_into().map_err(|_| ValueTypeErr),
-        Value::Unsigned(Some(int)) => int.try_into().map_err(|_| ValueTypeErr),
-        Value::BigUnsigned(Some(int)) => int.try_into().map_err(|_| ValueTypeErr),
-        _ => Err(ValueTypeErr),
-    }
-}
-
 id_type!(BufferId);
 id_type!(AccessTokenId);
 id_type!(ChannelChatParticipantId);

crates/collab/src/db/queries/buffers.rs

@@ -2,6 +2,12 @@ use super::*;
 use prost::Message;
 use text::{EditOperation, UndoOperation};
 
+pub struct LeftChannelBuffer {
+    pub channel_id: ChannelId,
+    pub collaborators: Vec<proto::Collaborator>,
+    pub connections: Vec<ConnectionId>,
+}
+
 impl Database {
     pub async fn join_channel_buffer(
         &self,
@@ -68,7 +74,32 @@ impl Database {
             .await?;
             collaborators.push(collaborator);
 
-            let (base_text, operations) = self.get_buffer_state(&buffer, &tx).await?;
+            let (base_text, operations, max_operation) =
+                self.get_buffer_state(&buffer, &tx).await?;
+
+            // Save the last observed operation
+            if let Some(op) = max_operation {
+                observed_buffer_edits::Entity::insert(observed_buffer_edits::ActiveModel {
+                    user_id: ActiveValue::Set(user_id),
+                    buffer_id: ActiveValue::Set(buffer.id),
+                    epoch: ActiveValue::Set(op.epoch),
+                    lamport_timestamp: ActiveValue::Set(op.lamport_timestamp),
+                    replica_id: ActiveValue::Set(op.replica_id),
+                })
+                .on_conflict(
+                    OnConflict::columns([
+                        observed_buffer_edits::Column::UserId,
+                        observed_buffer_edits::Column::BufferId,
+                    ])
+                    .update_columns([
+                        observed_buffer_edits::Column::Epoch,
+                        observed_buffer_edits::Column::LamportTimestamp,
+                    ])
+                    .to_owned(),
+                )
+                .exec(&*tx)
+                .await?;
+            }
 
             Ok(proto::JoinChannelBufferResponse {
                 buffer_id: buffer.id.to_proto(),
@@ -204,23 +235,26 @@ impl Database {
         server_id: ServerId,
     ) -> Result<RefreshedChannelBuffer> {
         self.transaction(|tx| async move {
-            let collaborators = channel_buffer_collaborator::Entity::find()
+            let db_collaborators = channel_buffer_collaborator::Entity::find()
                 .filter(channel_buffer_collaborator::Column::ChannelId.eq(channel_id))
                 .all(&*tx)
                 .await?;
 
             let mut connection_ids = Vec::new();
-            let mut removed_collaborators = Vec::new();
+            let mut collaborators = Vec::new();
             let mut collaborator_ids_to_remove = Vec::new();
-            for collaborator in &collaborators {
-                if !collaborator.connection_lost && collaborator.connection_server_id == server_id {
-                    connection_ids.push(collaborator.connection());
+            for db_collaborator in &db_collaborators {
+                if !db_collaborator.connection_lost
+                    && db_collaborator.connection_server_id == server_id
+                {
+                    connection_ids.push(db_collaborator.connection());
+                    collaborators.push(proto::Collaborator {
+                        peer_id: Some(db_collaborator.connection().into()),
+                        replica_id: db_collaborator.replica_id.0 as u32,
+                        user_id: db_collaborator.user_id.to_proto(),
+                    })
                 } else {
-                    removed_collaborators.push(proto::RemoveChannelBufferCollaborator {
-                        channel_id: channel_id.to_proto(),
-                        peer_id: Some(collaborator.connection().into()),
-                    });
-                    collaborator_ids_to_remove.push(collaborator.id);
+                    collaborator_ids_to_remove.push(db_collaborator.id);
                 }
             }
 
@@ -231,7 +265,7 @@ impl Database {
 
             Ok(RefreshedChannelBuffer {
                 connection_ids,
-                removed_collaborators,
+                collaborators,
             })
         })
         .await
@@ -241,7 +275,7 @@ impl Database {
         &self,
         channel_id: ChannelId,
         connection: ConnectionId,
-    ) -> Result<Vec<ConnectionId>> {
+    ) -> Result<LeftChannelBuffer> {
         self.transaction(|tx| async move {
             self.leave_channel_buffer_internal(channel_id, connection, &*tx)
                 .await
@@ -275,7 +309,7 @@ impl Database {
     pub async fn leave_channel_buffers(
         &self,
         connection: ConnectionId,
-    ) -> Result<Vec<(ChannelId, Vec<ConnectionId>)>> {
+    ) -> Result<Vec<LeftChannelBuffer>> {
         self.transaction(|tx| async move {
             #[derive(Debug, Clone, Copy, EnumIter, DeriveColumn)]
             enum QueryChannelIds {
@@ -294,10 +328,10 @@ impl Database {
 
             let mut result = Vec::new();
             for channel_id in channel_ids {
-                let collaborators = self
+                let left_channel_buffer = self
                     .leave_channel_buffer_internal(channel_id, connection, &*tx)
                     .await?;
-                result.push((channel_id, collaborators));
+                result.push(left_channel_buffer);
             }
 
             Ok(result)
@@ -310,7 +344,7 @@ impl Database {
         channel_id: ChannelId,
         connection: ConnectionId,
         tx: &DatabaseTransaction,
-    ) -> Result<Vec<ConnectionId>> {
+    ) -> Result<LeftChannelBuffer> {
         let result = channel_buffer_collaborator::Entity::delete_many()
             .filter(
                 Condition::all()
@@ -327,6 +361,7 @@ impl Database {
             Err(anyhow!("not a collaborator on this project"))?;
         }
 
+        let mut collaborators = Vec::new();
         let mut connections = Vec::new();
         let mut rows = channel_buffer_collaborator::Entity::find()
             .filter(
@@ -336,19 +371,26 @@ impl Database {
             .await?;
         while let Some(row) = rows.next().await {
             let row = row?;
-            connections.push(ConnectionId {
-                id: row.connection_id as u32,
-                owner_id: row.connection_server_id.0 as u32,
+            let connection = row.connection();
+            connections.push(connection);
+            collaborators.push(proto::Collaborator {
+                peer_id: Some(connection.into()),
+                replica_id: row.replica_id.0 as u32,
+                user_id: row.user_id.to_proto(),
             });
         }
 
         drop(rows);
 
-        if connections.is_empty() {
+        if collaborators.is_empty() {
             self.snapshot_channel_buffer(channel_id, &tx).await?;
         }
 
-        Ok(connections)
+        Ok(LeftChannelBuffer {
+            channel_id,
+            collaborators,
+            connections,
+        })
     }
 
     pub async fn get_channel_buffer_collaborators(
@@ -356,33 +398,46 @@ impl Database {
         channel_id: ChannelId,
     ) -> Result<Vec<UserId>> {
         self.transaction(|tx| async move {
-            #[derive(Debug, Clone, Copy, EnumIter, DeriveColumn)]
-            enum QueryUserIds {
-                UserId,
-            }
-
-            let users: Vec<UserId> = channel_buffer_collaborator::Entity::find()
-                .select_only()
-                .column(channel_buffer_collaborator::Column::UserId)
-                .filter(
-                    Condition::all()
-                        .add(channel_buffer_collaborator::Column::ChannelId.eq(channel_id)),
-                )
-                .into_values::<_, QueryUserIds>()
-                .all(&*tx)
-                .await?;
-
-            Ok(users)
+            self.get_channel_buffer_collaborators_internal(channel_id, &*tx)
+                .await
         })
         .await
     }
 
+    async fn get_channel_buffer_collaborators_internal(
+        &self,
+        channel_id: ChannelId,
+        tx: &DatabaseTransaction,
+    ) -> Result<Vec<UserId>> {
+        #[derive(Debug, Clone, Copy, EnumIter, DeriveColumn)]
+        enum QueryUserIds {
+            UserId,
+        }
+
+        let users: Vec<UserId> = channel_buffer_collaborator::Entity::find()
+            .select_only()
+            .column(channel_buffer_collaborator::Column::UserId)
+            .filter(
+                Condition::all().add(channel_buffer_collaborator::Column::ChannelId.eq(channel_id)),
+            )
+            .into_values::<_, QueryUserIds>()
+            .all(&*tx)
+            .await?;
+
+        Ok(users)
+    }
+
     pub async fn update_channel_buffer(
         &self,
         channel_id: ChannelId,
         user: UserId,
         operations: &[proto::Operation],
-    ) -> Result<Vec<ConnectionId>> {
+    ) -> Result<(
+        Vec<ConnectionId>,
+        Vec<UserId>,
+        i32,
+        Vec<proto::VectorClockEntry>,
+    )> {
         self.transaction(move |tx| async move {
             self.check_user_is_channel_member(channel_id, user, &*tx)
                 .await?;
@@ -401,7 +456,38 @@ impl Database {
                 .iter()
                 .filter_map(|op| operation_to_storage(op, &buffer, serialization_version))
                 .collect::<Vec<_>>();
+
+            let mut channel_members;
+            let max_version;
+
             if !operations.is_empty() {
+                let max_operation = operations
+                    .iter()
+                    .max_by_key(|op| (op.lamport_timestamp.as_ref(), op.replica_id.as_ref()))
+                    .unwrap();
+
+                max_version = vec![proto::VectorClockEntry {
+                    replica_id: *max_operation.replica_id.as_ref() as u32,
+                    timestamp: *max_operation.lamport_timestamp.as_ref() as u32,
+                }];
+
+                // get current channel participants and save the max operation above
+                self.save_max_operation(
+                    user,
+                    buffer.id,
+                    buffer.epoch,
+                    *max_operation.replica_id.as_ref(),
+                    *max_operation.lamport_timestamp.as_ref(),
+                    &*tx,
+                )
+                .await?;
+
+                channel_members = self.get_channel_members_internal(channel_id, &*tx).await?;
+                let collaborators = self
+                    .get_channel_buffer_collaborators_internal(channel_id, &*tx)
+                    .await?;
+                channel_members.retain(|member| !collaborators.contains(member));
+
                 buffer_operation::Entity::insert_many(operations)
                     .on_conflict(
                         OnConflict::columns([
@@ -415,6 +501,9 @@ impl Database {
                     )
                     .exec(&*tx)
                     .await?;
+            } else {
+                channel_members = Vec::new();
+                max_version = Vec::new();
             }
 
             let mut connections = Vec::new();
@@ -433,11 +522,53 @@ impl Database {
                 });
             }
 
-            Ok(connections)
+            Ok((connections, channel_members, buffer.epoch, max_version))
         })
         .await
     }
 
+    async fn save_max_operation(
+        &self,
+        user_id: UserId,
+        buffer_id: BufferId,
+        epoch: i32,
+        replica_id: i32,
+        lamport_timestamp: i32,
+        tx: &DatabaseTransaction,
+    ) -> Result<()> {
+        use observed_buffer_edits::Column;
+
+        observed_buffer_edits::Entity::insert(observed_buffer_edits::ActiveModel {
+            user_id: ActiveValue::Set(user_id),
+            buffer_id: ActiveValue::Set(buffer_id),
+            epoch: ActiveValue::Set(epoch),
+            replica_id: ActiveValue::Set(replica_id),
+            lamport_timestamp: ActiveValue::Set(lamport_timestamp),
+        })
+        .on_conflict(
+            OnConflict::columns([Column::UserId, Column::BufferId])
+                .update_columns([Column::Epoch, Column::LamportTimestamp, Column::ReplicaId])
+                .action_cond_where(
+                    Condition::any().add(Column::Epoch.lt(epoch)).add(
+                        Condition::all().add(Column::Epoch.eq(epoch)).add(
+                            Condition::any()
+                                .add(Column::LamportTimestamp.lt(lamport_timestamp))
+                                .add(
+                                    Column::LamportTimestamp
+                                        .eq(lamport_timestamp)
+                                        .and(Column::ReplicaId.lt(replica_id)),
+                                ),
+                        ),
+                    ),
+                )
+                .to_owned(),
+        )
+        .exec_without_returning(tx)
+        .await?;
+
+        Ok(())
+    }
+
     async fn get_buffer_operation_serialization_version(
         &self,
         buffer_id: BufferId,
@@ -455,7 +586,7 @@ impl Database {
             .ok_or_else(|| anyhow!("missing buffer snapshot"))?)
     }
 
-    async fn get_channel_buffer(
+    pub async fn get_channel_buffer(
         &self,
         channel_id: ChannelId,
         tx: &DatabaseTransaction,
@@ -474,7 +605,11 @@ impl Database {
         &self,
         buffer: &buffer::Model,
         tx: &DatabaseTransaction,
-    ) -> Result<(String, Vec<proto::Operation>)> {
+    ) -> Result<(
+        String,
+        Vec<proto::Operation>,
+        Option<buffer_operation::Model>,
+    )> {
         let id = buffer.id;
         let (base_text, version) = if buffer.epoch > 0 {
             let snapshot = buffer_snapshot::Entity::find()
@@ -499,16 +634,28 @@ impl Database {
                     .eq(id)
                     .and(buffer_operation::Column::Epoch.eq(buffer.epoch)),
             )
+            .order_by_asc(buffer_operation::Column::LamportTimestamp)
+            .order_by_asc(buffer_operation::Column::ReplicaId)
             .stream(&*tx)
             .await?;
+
         let mut operations = Vec::new();
+        let mut last_row = None;
         while let Some(row) = rows.next().await {
+            let row = row?;
+            last_row = Some(buffer_operation::Model {
+                buffer_id: row.buffer_id,
+                epoch: row.epoch,
+                lamport_timestamp: row.lamport_timestamp,
+                replica_id: row.lamport_timestamp,
+                value: Default::default(),
+            });
             operations.push(proto::Operation {
-                variant: Some(operation_from_storage(row?, version)?),
-            })
+                variant: Some(operation_from_storage(row, version)?),
+            });
         }
 
-        Ok((base_text, operations))
+        Ok((base_text, operations, last_row))
     }
 
     async fn snapshot_channel_buffer(
@@ -517,7 +664,7 @@ impl Database {
         tx: &DatabaseTransaction,
     ) -> Result<()> {
         let buffer = self.get_channel_buffer(channel_id, tx).await?;
-        let (base_text, operations) = self.get_buffer_state(&buffer, tx).await?;
+        let (base_text, operations, _) = self.get_buffer_state(&buffer, tx).await?;
         if operations.is_empty() {
             return Ok(());
         }
@@ -550,6 +697,150 @@ impl Database {
 
         Ok(())
     }
+
+    pub async fn observe_buffer_version(
+        &self,
+        buffer_id: BufferId,
+        user_id: UserId,
+        epoch: i32,
+        version: &[proto::VectorClockEntry],
+    ) -> Result<()> {
+        self.transaction(|tx| async move {
+            // For now, combine concurrent operations.
+            let Some(component) = version.iter().max_by_key(|version| version.timestamp) else {
+                return Ok(());
+            };
+            self.save_max_operation(
+                user_id,
+                buffer_id,
+                epoch,
+                component.replica_id as i32,
+                component.timestamp as i32,
+                &*tx,
+            )
+            .await?;
+            Ok(())
+        })
+        .await
+    }
+
+    pub async fn unseen_channel_buffer_changes(
+        &self,
+        user_id: UserId,
+        channel_ids: &[ChannelId],
+        tx: &DatabaseTransaction,
+    ) -> Result<Vec<proto::UnseenChannelBufferChange>> {
+        #[derive(Debug, Clone, Copy, EnumIter, DeriveColumn)]
+        enum QueryIds {
+            ChannelId,
+            Id,
+        }
+
+        let mut channel_ids_by_buffer_id = HashMap::default();
+        let mut rows = buffer::Entity::find()
+            .filter(buffer::Column::ChannelId.is_in(channel_ids.iter().copied()))
+            .stream(&*tx)
+            .await?;
+        while let Some(row) = rows.next().await {
+            let row = row?;
+            channel_ids_by_buffer_id.insert(row.id, row.channel_id);
+        }
+        drop(rows);
+
+        let mut observed_edits_by_buffer_id = HashMap::default();
+        let mut rows = observed_buffer_edits::Entity::find()
+            .filter(observed_buffer_edits::Column::UserId.eq(user_id))
+            .filter(
+                observed_buffer_edits::Column::BufferId
+                    .is_in(channel_ids_by_buffer_id.keys().copied()),
+            )
+            .stream(&*tx)
+            .await?;
+        while let Some(row) = rows.next().await {
+            let row = row?;
+            observed_edits_by_buffer_id.insert(row.buffer_id, row);
+        }
+        drop(rows);
+
+        let latest_operations = self
+            .get_latest_operations_for_buffers(channel_ids_by_buffer_id.keys().copied(), &*tx)
+            .await?;
+
+        let mut changes = Vec::default();
+        for latest in latest_operations {
+            if let Some(observed) = observed_edits_by_buffer_id.get(&latest.buffer_id) {
+                if (
+                    observed.epoch,
+                    observed.lamport_timestamp,
+                    observed.replica_id,
+                ) >= (latest.epoch, latest.lamport_timestamp, latest.replica_id)
+                {
+                    continue;
+                }
+            }
+
+            if let Some(channel_id) = channel_ids_by_buffer_id.get(&latest.buffer_id) {
+                changes.push(proto::UnseenChannelBufferChange {
+                    channel_id: channel_id.to_proto(),
+                    epoch: latest.epoch as u64,
+                    version: vec![proto::VectorClockEntry {
+                        replica_id: latest.replica_id as u32,
+                        timestamp: latest.lamport_timestamp as u32,
+                    }],
+                });
+            }
+        }
+
+        Ok(changes)
+    }
+
+    pub async fn get_latest_operations_for_buffers(
+        &self,
+        buffer_ids: impl IntoIterator<Item = BufferId>,
+        tx: &DatabaseTransaction,
+    ) -> Result<Vec<buffer_operation::Model>> {
+        let mut values = String::new();
+        for id in buffer_ids {
+            if !values.is_empty() {
+                values.push_str(", ");
+            }
+            write!(&mut values, "({})", id).unwrap();
+        }
+
+        if values.is_empty() {
+            return Ok(Vec::default());
+        }
+
+        let sql = format!(
+            r#"
+            SELECT
+                *
+            FROM
+            (
+                SELECT
+                    *,
+                    row_number() OVER (
+                        PARTITION BY buffer_id
+                        ORDER BY
+                            epoch DESC,
+                            lamport_timestamp DESC,
+                            replica_id DESC
+                    ) as row_number
+                FROM buffer_operations
+                WHERE
+                    buffer_id in ({values})
+            ) AS last_operations
+            WHERE
+                row_number = 1
+            "#,
+        );
+
+        let stmt = Statement::from_string(self.pool.get_database_backend(), sql);
+        Ok(buffer_operation::Entity::find()
+            .from_raw_sql(stmt)
+            .all(&*tx)
+            .await?)
+    }
 }
 
 fn operation_to_storage(

crates/collab/src/db/queries/channels.rs

@@ -1,8 +1,7 @@
+use super::*;
 use rpc::proto::ChannelEdge;
 use smallvec::SmallVec;
 
-use super::*;
-
 type ChannelDescendants = HashMap<ChannelId, SmallSet<ChannelId>>;
 
 impl Database {
@@ -391,7 +390,8 @@ impl Database {
                 .all(&*tx)
                 .await?;
 
-            self.get_user_channels(channel_memberships, &tx).await
+            self.get_user_channels(user_id, channel_memberships, &tx)
+                .await
         })
         .await
     }
@@ -414,13 +414,15 @@ impl Database {
                 .all(&*tx)
                 .await?;
 
-            self.get_user_channels(channel_membership, &tx).await
+            self.get_user_channels(user_id, channel_membership, &tx)
+                .await
         })
         .await
     }
 
     pub async fn get_user_channels(
         &self,
+        user_id: UserId,
         channel_memberships: Vec<channel_member::Model>,
         tx: &DatabaseTransaction,
     ) -> Result<ChannelsForUser> {
@@ -460,10 +462,21 @@ impl Database {
             }
         }
 
+        let channel_ids = graph.channels.iter().map(|c| c.id).collect::<Vec<_>>();
+        let channel_buffer_changes = self
+            .unseen_channel_buffer_changes(user_id, &channel_ids, &*tx)
+            .await?;
+
+        let unseen_messages = self
+            .unseen_channel_messages(user_id, &channel_ids, &*tx)
+            .await?;
+
         Ok(ChannelsForUser {
             channels: graph,
             channel_participants,
             channels_with_admin_privileges,
+            unseen_buffer_changes: channel_buffer_changes,
+            channel_messages: unseen_messages,
         })
     }
 
@@ -645,7 +658,7 @@ impl Database {
     ) -> Result<Vec<ChannelId>> {
         let paths = channel_path::Entity::find()
             .filter(channel_path::Column::ChannelId.eq(channel_id))
-            .order_by(channel_path::Column::IdPath, sea_query::Order::Desc)
+            .order_by(channel_path::Column::IdPath, sea_orm::Order::Desc)
             .all(tx)
             .await?;
         let mut channel_ids = Vec::new();

crates/collab/src/db/queries/contacts.rs

@@ -18,12 +18,12 @@ impl Database {
             let user_b_participant = Alias::new("user_b_participant");
             let mut db_contacts = contact::Entity::find()
                 .column_as(
-                    Expr::tbl(user_a_participant.clone(), room_participant::Column::Id)
+                    Expr::col((user_a_participant.clone(), room_participant::Column::Id))
                         .is_not_null(),
                     "user_a_busy",
                 )
                 .column_as(
-                    Expr::tbl(user_b_participant.clone(), room_participant::Column::Id)
+                    Expr::col((user_b_participant.clone(), room_participant::Column::Id))
                         .is_not_null(),
                     "user_b_busy",
                 )

crates/collab/src/db/queries/messages.rs

@@ -89,6 +89,7 @@ impl Database {
 
             let mut rows = channel_message::Entity::find()
                 .filter(condition)
+                .order_by_asc(channel_message::Column::Id)
                 .limit(count as u64)
                 .stream(&*tx)
                 .await?;
@@ -108,7 +109,7 @@ impl Database {
                     }),
                 });
             }
-
+            drop(rows);
             Ok(messages)
         })
         .await
@@ -121,7 +122,7 @@ impl Database {
         body: &str,
         timestamp: OffsetDateTime,
         nonce: u128,
-    ) -> Result<(MessageId, Vec<ConnectionId>)> {
+    ) -> Result<(MessageId, Vec<ConnectionId>, Vec<UserId>)> {
         self.transaction(|tx| async move {
             let mut rows = channel_chat_participant::Entity::find()
                 .filter(channel_chat_participant::Column::ChannelId.eq(channel_id))
@@ -130,11 +131,13 @@ impl Database {
 
             let mut is_participant = false;
             let mut participant_connection_ids = Vec::new();
+            let mut participant_user_ids = Vec::new();
             while let Some(row) = rows.next().await {
                 let row = row?;
                 if row.user_id == user_id {
                     is_participant = true;
                 }
+                participant_user_ids.push(row.user_id);
                 participant_connection_ids.push(row.connection());
             }
             drop(rows);
@@ -167,11 +170,141 @@ impl Database {
                 ConnectionId,
             }
 
-            Ok((message.last_insert_id, participant_connection_ids))
+            // Observe this message for the sender
+            self.observe_channel_message_internal(
+                channel_id,
+                user_id,
+                message.last_insert_id,
+                &*tx,
+            )
+            .await?;
+
+            let mut channel_members = self.get_channel_members_internal(channel_id, &*tx).await?;
+            channel_members.retain(|member| !participant_user_ids.contains(member));
+
+            Ok((
+                message.last_insert_id,
+                participant_connection_ids,
+                channel_members,
+            ))
         })
         .await
     }
 
+    pub async fn observe_channel_message(
+        &self,
+        channel_id: ChannelId,
+        user_id: UserId,
+        message_id: MessageId,
+    ) -> Result<()> {
+        self.transaction(|tx| async move {
+            self.observe_channel_message_internal(channel_id, user_id, message_id, &*tx)
+                .await?;
+            Ok(())
+        })
+        .await
+    }
+
+    async fn observe_channel_message_internal(
+        &self,
+        channel_id: ChannelId,
+        user_id: UserId,
+        message_id: MessageId,
+        tx: &DatabaseTransaction,
+    ) -> Result<()> {
+        observed_channel_messages::Entity::insert(observed_channel_messages::ActiveModel {
+            user_id: ActiveValue::Set(user_id),
+            channel_id: ActiveValue::Set(channel_id),
+            channel_message_id: ActiveValue::Set(message_id),
+        })
+        .on_conflict(
+            OnConflict::columns([
+                observed_channel_messages::Column::ChannelId,
+                observed_channel_messages::Column::UserId,
+            ])
+            .update_column(observed_channel_messages::Column::ChannelMessageId)
+            .action_cond_where(observed_channel_messages::Column::ChannelMessageId.lt(message_id))
+            .to_owned(),
+        )
+        // TODO: Try to upgrade SeaORM so we don't have to do this hack around their bug
+        .exec_without_returning(&*tx)
+        .await?;
+        Ok(())
+    }
+
+    pub async fn unseen_channel_messages(
+        &self,
+        user_id: UserId,
+        channel_ids: &[ChannelId],
+        tx: &DatabaseTransaction,
+    ) -> Result<Vec<proto::UnseenChannelMessage>> {
+        let mut observed_messages_by_channel_id = HashMap::default();
+        let mut rows = observed_channel_messages::Entity::find()
+            .filter(observed_channel_messages::Column::UserId.eq(user_id))
+            .filter(observed_channel_messages::Column::ChannelId.is_in(channel_ids.iter().copied()))
+            .stream(&*tx)
+            .await?;
+
+        while let Some(row) = rows.next().await {
+            let row = row?;
+            observed_messages_by_channel_id.insert(row.channel_id, row);
+        }
+        drop(rows);
+        let mut values = String::new();
+        for id in channel_ids {
+            if !values.is_empty() {
+                values.push_str(", ");
+            }
+            write!(&mut values, "({})", id).unwrap();
+        }
+
+        if values.is_empty() {
+            return Ok(Default::default());
+        }
+
+        let sql = format!(
+            r#"
+            SELECT
+                *
+            FROM (
+                SELECT
+                    *,
+                    row_number() OVER (
+                        PARTITION BY channel_id
+                        ORDER BY id DESC
+                    ) as row_number
+                FROM channel_messages
+                WHERE
+                    channel_id in ({values})
+            ) AS messages
+            WHERE
+                row_number = 1
+            "#,
+        );
+
+        let stmt = Statement::from_string(self.pool.get_database_backend(), sql);
+        let last_messages = channel_message::Model::find_by_statement(stmt)
+            .all(&*tx)
+            .await?;
+
+        let mut changes = Vec::new();
+        for last_message in last_messages {
+            if let Some(observed_message) =
+                observed_messages_by_channel_id.get(&last_message.channel_id)
+            {
+                if observed_message.channel_message_id == last_message.id {
+                    continue;
+                }
+            }
+            changes.push(proto::UnseenChannelMessage {
+                channel_id: last_message.channel_id.to_proto(),
+                message_id: last_message.id.to_proto(),
+            });
+        }
+
+        Ok(changes)
+    }
+
     pub async fn remove_channel_message(
         &self,
         channel_id: ChannelId,

crates/collab/src/db/queries/projects.rs

@@ -738,7 +738,7 @@ impl Database {
                     Condition::any()
                         .add(
                             Condition::all()
-                                .add(follower::Column::ProjectId.eq(project_id))
+                                .add(follower::Column::ProjectId.eq(Some(project_id)))
                                 .add(
                                     follower::Column::LeaderConnectionServerId
                                         .eq(connection.owner_id),
@@ -747,7 +747,7 @@ impl Database {
                         )
                         .add(
                             Condition::all()
-                                .add(follower::Column::ProjectId.eq(project_id))
+                                .add(follower::Column::ProjectId.eq(Some(project_id)))
                                 .add(
                                     follower::Column::FollowerConnectionServerId
                                         .eq(connection.owner_id),
@@ -862,13 +862,46 @@ impl Database {
         .await
     }
 
+    pub async fn check_room_participants(
+        &self,
+        room_id: RoomId,
+        leader_id: ConnectionId,
+        follower_id: ConnectionId,
+    ) -> Result<()> {
+        self.transaction(|tx| async move {
+            use room_participant::Column;
+
+            let count = room_participant::Entity::find()
+                .filter(
+                    Condition::all().add(Column::RoomId.eq(room_id)).add(
+                        Condition::any()
+                            .add(Column::AnsweringConnectionId.eq(leader_id.id as i32).and(
+                                Column::AnsweringConnectionServerId.eq(leader_id.owner_id as i32),
+                            ))
+                            .add(Column::AnsweringConnectionId.eq(follower_id.id as i32).and(
+                                Column::AnsweringConnectionServerId.eq(follower_id.owner_id as i32),
+                            )),
+                    ),
+                )
+                .count(&*tx)
+                .await?;
+
+            if count < 2 {
+                Err(anyhow!("not room participants"))?;
+            }
+
+            Ok(())
+        })
+        .await
+    }
+
     pub async fn follow(
         &self,
+        room_id: RoomId,
         project_id: ProjectId,
         leader_connection: ConnectionId,
         follower_connection: ConnectionId,
     ) -> Result<RoomGuard<proto::Room>> {
-        let room_id = self.room_id_for_project(project_id).await?;
         self.room_transaction(room_id, |tx| async move {
             follower::ActiveModel {
                 room_id: ActiveValue::set(room_id),
@@ -894,15 +927,16 @@ impl Database {
 
     pub async fn unfollow(
         &self,
+        room_id: RoomId,
         project_id: ProjectId,
         leader_connection: ConnectionId,
         follower_connection: ConnectionId,
     ) -> Result<RoomGuard<proto::Room>> {
-        let room_id = self.room_id_for_project(project_id).await?;
         self.room_transaction(room_id, |tx| async move {
             follower::Entity::delete_many()
                 .filter(
                     Condition::all()
+                        .add(follower::Column::RoomId.eq(room_id))
                         .add(follower::Column::ProjectId.eq(project_id))
                         .add(
                             follower::Column::LeaderConnectionServerId

crates/collab/src/db/queries/rooms.rs

@@ -128,6 +128,7 @@ impl Database {
                 calling_connection_server_id: ActiveValue::set(Some(ServerId(
                     connection.owner_id as i32,
                 ))),
+                participant_index: ActiveValue::set(Some(0)),
                 ..Default::default()
             }
             .insert(&*tx)
@@ -152,6 +153,7 @@ impl Database {
                 room_id: ActiveValue::set(room_id),
                 user_id: ActiveValue::set(called_user_id),
                 answering_connection_lost: ActiveValue::set(false),
+                participant_index: ActiveValue::NotSet,
                 calling_user_id: ActiveValue::set(calling_user_id),
                 calling_connection_id: ActiveValue::set(calling_connection.id as i32),
                 calling_connection_server_id: ActiveValue::set(Some(ServerId(
@@ -283,6 +285,26 @@ impl Database {
                 .await?
                 .ok_or_else(|| anyhow!("no such room"))?;
 
+            #[derive(Copy, Clone, Debug, EnumIter, DeriveColumn)]
+            enum QueryParticipantIndices {
+                ParticipantIndex,
+            }
+            let existing_participant_indices: Vec<i32> = room_participant::Entity::find()
+                .filter(
+                    room_participant::Column::RoomId
+                        .eq(room_id)
+                        .and(room_participant::Column::ParticipantIndex.is_not_null()),
+                )
+                .select_only()
+                .column(room_participant::Column::ParticipantIndex)
+                .into_values::<_, QueryParticipantIndices>()
+                .all(&*tx)
+                .await?;
+            let mut participant_index = 0;
+            while existing_participant_indices.contains(&participant_index) {
+                participant_index += 1;
+            }
+
             if let Some(channel_id) = channel_id {
                 self.check_user_is_channel_member(channel_id, user_id, &*tx)
                     .await?;
@@ -300,6 +322,7 @@ impl Database {
                     calling_connection_server_id: ActiveValue::set(Some(ServerId(
                         connection.owner_id as i32,
                     ))),
+                    participant_index: ActiveValue::Set(Some(participant_index)),
                     ..Default::default()
                 }])
                 .on_conflict(
@@ -308,6 +331,7 @@ impl Database {
                             room_participant::Column::AnsweringConnectionId,
                             room_participant::Column::AnsweringConnectionServerId,
                             room_participant::Column::AnsweringConnectionLost,
+                            room_participant::Column::ParticipantIndex,
                         ])
                         .to_owned(),
                 )
@@ -322,6 +346,7 @@ impl Database {
                             .add(room_participant::Column::AnsweringConnectionId.is_null()),
                     )
                     .set(room_participant::ActiveModel {
+                        participant_index: ActiveValue::Set(Some(participant_index)),
                         answering_connection_id: ActiveValue::set(Some(connection.id as i32)),
                         answering_connection_server_id: ActiveValue::set(Some(ServerId(
                             connection.owner_id as i32,
@@ -960,6 +985,39 @@ impl Database {
         Ok(room)
     }
 
+    pub async fn room_connection_ids(
+        &self,
+        room_id: RoomId,
+        connection_id: ConnectionId,
+    ) -> Result<RoomGuard<HashSet<ConnectionId>>> {
+        self.room_transaction(room_id, |tx| async move {
+            let mut participants = room_participant::Entity::find()
+                .filter(room_participant::Column::RoomId.eq(room_id))
+                .stream(&*tx)
+                .await?;
+
+            let mut is_participant = false;
+            let mut connection_ids = HashSet::default();
+            while let Some(participant) = participants.next().await {
+                let participant = participant?;
+                if let Some(answering_connection) = participant.answering_connection() {
+                    if answering_connection == connection_id {
+                        is_participant = true;
+                    } else {
+                        connection_ids.insert(answering_connection);
+                    }
+                }
+            }
+
+            if !is_participant {
+                Err(anyhow!("not a room participant"))?;
+            }
+
+            Ok(connection_ids)
+        })
+        .await
+    }
+
     async fn get_channel_room(
         &self,
         room_id: RoomId,
@@ -978,10 +1036,15 @@ impl Database {
         let mut pending_participants = Vec::new();
         while let Some(db_participant) = db_participants.next().await {
             let db_participant = db_participant?;
-            if let Some((answering_connection_id, answering_connection_server_id)) = db_participant
-                .answering_connection_id
-                .zip(db_participant.answering_connection_server_id)
-            {
+            if let (
+                Some(answering_connection_id),
+                Some(answering_connection_server_id),
+                Some(participant_index),
+            ) = (
+                db_participant.answering_connection_id,
+                db_participant.answering_connection_server_id,
+                db_participant.participant_index,
+            ) {
                 let location = match (
                     db_participant.location_kind,
                     db_participant.location_project_id,
@@ -1012,6 +1075,7 @@ impl Database {
                         peer_id: Some(answering_connection.into()),
                         projects: Default::default(),
                         location: Some(proto::ParticipantLocation { variant: location }),
+                        participant_index: participant_index as u32,
                     },
                 );
             } else {

crates/collab/src/db/queries/users.rs

@@ -184,7 +184,7 @@ impl Database {
             Ok(user::Entity::find()
                 .from_raw_sql(Statement::from_sql_and_values(
                     self.pool.get_database_backend(),
-                    query.into(),
+                    query,
                     vec![like_string.into(), name_query.into(), limit.into()],
                 ))
                 .all(&*tx)

crates/collab/src/db/tables.rs

@@ -12,6 +12,8 @@ pub mod contact;
 pub mod feature_flag;
 pub mod follower;
 pub mod language_server;
+pub mod observed_buffer_edits;
+pub mod observed_channel_messages;
 pub mod project;
 pub mod project_collaborator;
 pub mod room;

crates/collab/src/db/tables/observed_buffer_edits.rs

@@ -0,0 +1,43 @@
+use crate::db::{BufferId, UserId};
+use sea_orm::entity::prelude::*;
+
+#[derive(Clone, Debug, PartialEq, Eq, DeriveEntityModel)]
+#[sea_orm(table_name = "observed_buffer_edits")]
+pub struct Model {
+    #[sea_orm(primary_key)]
+    pub user_id: UserId,
+    pub buffer_id: BufferId,
+    pub epoch: i32,
+    pub lamport_timestamp: i32,
+    pub replica_id: i32,
+}
+
+#[derive(Copy, Clone, Debug, EnumIter, DeriveRelation)]
+pub enum Relation {
+    #[sea_orm(
+        belongs_to = "super::buffer::Entity",
+        from = "Column::BufferId",
+        to = "super::buffer::Column::Id"
+    )]
+    Buffer,
+    #[sea_orm(
+        belongs_to = "super::user::Entity",
+        from = "Column::UserId",
+        to = "super::user::Column::Id"
+    )]
+    User,
+}
+
+impl Related<super::buffer::Entity> for Entity {
+    fn to() -> RelationDef {
+        Relation::Buffer.def()
+    }
+}
+
+impl Related<super::user::Entity> for Entity {
+    fn to() -> RelationDef {
+        Relation::User.def()
+    }
+}
+
+impl ActiveModelBehavior for ActiveModel {}

crates/collab/src/db/tables/observed_channel_messages.rs

@@ -0,0 +1,41 @@
+use crate::db::{ChannelId, MessageId, UserId};
+use sea_orm::entity::prelude::*;
+
+#[derive(Clone, Debug, PartialEq, Eq, DeriveEntityModel)]
+#[sea_orm(table_name = "observed_channel_messages")]
+pub struct Model {
+    #[sea_orm(primary_key)]
+    pub user_id: UserId,
+    pub channel_id: ChannelId,
+    pub channel_message_id: MessageId,
+}
+
+#[derive(Copy, Clone, Debug, EnumIter, DeriveRelation)]
+pub enum Relation {
+    #[sea_orm(
+        belongs_to = "super::channel::Entity",
+        from = "Column::ChannelId",
+        to = "super::channel::Column::Id"
+    )]
+    Channel,
+    #[sea_orm(
+        belongs_to = "super::user::Entity",
+        from = "Column::UserId",
+        to = "super::user::Column::Id"
+    )]
+    User,
+}
+
+impl Related<super::channel::Entity> for Entity {
+    fn to() -> RelationDef {
+        Relation::Channel.def()
+    }
+}
+
+impl Related<super::user::Entity> for Entity {
+    fn to() -> RelationDef {
+        Relation::User.def()
+    }
+}
+
+impl ActiveModelBehavior for ActiveModel {}

crates/collab/src/db/tables/room_participant.rs

@@ -1,4 +1,5 @@
 use crate::db::{ProjectId, RoomId, RoomParticipantId, ServerId, UserId};
+use rpc::ConnectionId;
 use sea_orm::entity::prelude::*;
 
 #[derive(Clone, Debug, PartialEq, Eq, DeriveEntityModel)]
@@ -17,6 +18,16 @@ pub struct Model {
     pub calling_user_id: UserId,
     pub calling_connection_id: i32,
     pub calling_connection_server_id: Option<ServerId>,
+    pub participant_index: Option<i32>,
+}
+
+impl Model {
+    pub fn answering_connection(&self) -> Option<ConnectionId> {
+        Some(ConnectionId {
+            owner_id: self.answering_connection_server_id?.0 as u32,
+            id: self.answering_connection_id? as u32,
+        })
+    }
 }
 
 #[derive(Copy, Clone, Debug, EnumIter, DeriveRelation)]

crates/collab/src/db/tests.rs

@@ -39,7 +39,7 @@ impl TestDb {
             db.pool
                 .execute(sea_orm::Statement::from_string(
                     db.pool.get_database_backend(),
-                    sql.into(),
+                    sql,
                 ))
                 .await
                 .unwrap();
@@ -134,7 +134,7 @@ impl Drop for TestDb {
                 db.pool
                     .execute(sea_orm::Statement::from_string(
                         db.pool.get_database_backend(),
-                        query.into(),
+                        query,
                     ))
                     .await
                     .log_err();

crates/collab/src/db/tests/buffer_tests.rs

@@ -1,6 +1,6 @@
 use super::*;
 use crate::test_both_dbs;
-use language::proto;
+use language::proto::{self, serialize_version};
 use text::Buffer;
 
 test_both_dbs!(
@@ -134,12 +134,12 @@ async fn test_channel_buffers(db: &Arc<Database>) {
     let zed_collaborats = db.get_channel_buffer_collaborators(zed_id).await.unwrap();
     assert_eq!(zed_collaborats, &[a_id, b_id]);
 
-    let collaborators = db
+    let left_buffer = db
         .leave_channel_buffer(zed_id, connection_id_b)
         .await
         .unwrap();
 
-    assert_eq!(collaborators, &[connection_id_a],);
+    assert_eq!(left_buffer.connections, &[connection_id_a],);
 
     let cargo_id = db.create_root_channel("cargo", "2", a_id).await.unwrap();
     let _ = db
@@ -163,3 +163,349 @@ async fn test_channel_buffers(db: &Arc<Database>) {
     assert_eq!(buffer_response_b.base_text, "hello, cruel world");
     assert_eq!(buffer_response_b.operations, &[]);
 }
+
+test_both_dbs!(
+    test_channel_buffers_last_operations,
+    test_channel_buffers_last_operations_postgres,
+    test_channel_buffers_last_operations_sqlite
+);
+
+async fn test_channel_buffers_last_operations(db: &Database) {
+    let user_id = db
+        .create_user(
+            "user_a@example.com",
+            false,
+            NewUserParams {
+                github_login: "user_a".into(),
+                github_user_id: 101,
+                invite_count: 0,
+            },
+        )
+        .await
+        .unwrap()
+        .user_id;
+    let observer_id = db
+        .create_user(
+            "user_b@example.com",
+            false,
+            NewUserParams {
+                github_login: "user_b".into(),
+                github_user_id: 102,
+                invite_count: 0,
+            },
+        )
+        .await
+        .unwrap()
+        .user_id;
+    let owner_id = db.create_server("production").await.unwrap().0 as u32;
+    let connection_id = ConnectionId {
+        owner_id,
+        id: user_id.0 as u32,
+    };
+
+    let mut buffers = Vec::new();
+    let mut text_buffers = Vec::new();
+    for i in 0..3 {
+        let channel = db
+            .create_root_channel(&format!("channel-{i}"), &format!("room-{i}"), user_id)
+            .await
+            .unwrap();
+
+        db.invite_channel_member(channel, observer_id, user_id, false)
+            .await
+            .unwrap();
+        db.respond_to_channel_invite(channel, observer_id, true)
+            .await
+            .unwrap();
+
+        db.join_channel_buffer(channel, user_id, connection_id)
+            .await
+            .unwrap();
+
+        buffers.push(
+            db.transaction(|tx| async move { db.get_channel_buffer(channel, &*tx).await })
+                .await
+                .unwrap(),
+        );
+
+        text_buffers.push(Buffer::new(0, 0, "".to_string()));
+    }
+
+    let operations = db
+        .transaction(|tx| {
+            let buffers = &buffers;
+            async move {
+                db.get_latest_operations_for_buffers([buffers[0].id, buffers[2].id], &*tx)
+                    .await
+            }
+        })
+        .await
+        .unwrap();
+
+    assert!(operations.is_empty());
+
+    update_buffer(
+        buffers[0].channel_id,
+        user_id,
+        db,
+        vec![
+            text_buffers[0].edit([(0..0, "a")]),
+            text_buffers[0].edit([(0..0, "b")]),
+            text_buffers[0].edit([(0..0, "c")]),
+        ],
+    )
+    .await;
+
+    update_buffer(
+        buffers[1].channel_id,
+        user_id,
+        db,
+        vec![
+            text_buffers[1].edit([(0..0, "d")]),
+            text_buffers[1].edit([(1..1, "e")]),
+            text_buffers[1].edit([(2..2, "f")]),
+        ],
+    )
+    .await;
+
+    // cause buffer 1's epoch to increment.
+    db.leave_channel_buffer(buffers[1].channel_id, connection_id)
+        .await
+        .unwrap();
+    db.join_channel_buffer(buffers[1].channel_id, user_id, connection_id)
+        .await
+        .unwrap();
+    text_buffers[1] = Buffer::new(1, 0, "def".to_string());
+    update_buffer(
+        buffers[1].channel_id,
+        user_id,
+        db,
+        vec![
+            text_buffers[1].edit([(0..0, "g")]),
+            text_buffers[1].edit([(0..0, "h")]),
+        ],
+    )
+    .await;
+
+    update_buffer(
+        buffers[2].channel_id,
+        user_id,
+        db,
+        vec![text_buffers[2].edit([(0..0, "i")])],
+    )
+    .await;
+
+    let operations = db
+        .transaction(|tx| {
+            let buffers = &buffers;
+            async move {
+                db.get_latest_operations_for_buffers([buffers[1].id, buffers[2].id], &*tx)
+                    .await
+            }
+        })
+        .await
+        .unwrap();
+    assert_operations(
+        &operations,
+        &[
+            (buffers[1].id, 1, &text_buffers[1]),
+            (buffers[2].id, 0, &text_buffers[2]),
+        ],
+    );
+
+    let operations = db
+        .transaction(|tx| {
+            let buffers = &buffers;
+            async move {
+                db.get_latest_operations_for_buffers([buffers[0].id, buffers[1].id], &*tx)
+                    .await
+            }
+        })
+        .await
+        .unwrap();
+    assert_operations(
+        &operations,
+        &[
+            (buffers[0].id, 0, &text_buffers[0]),
+            (buffers[1].id, 1, &text_buffers[1]),
+        ],
+    );
+
+    let buffer_changes = db
+        .transaction(|tx| {
+            let buffers = &buffers;
+            async move {
+                db.unseen_channel_buffer_changes(
+                    observer_id,
+                    &[
+                        buffers[0].channel_id,
+                        buffers[1].channel_id,
+                        buffers[2].channel_id,
+                    ],
+                    &*tx,
+                )
+                .await
+            }
+        })
+        .await
+        .unwrap();
+
+    pretty_assertions::assert_eq!(
+        buffer_changes,
+        [
+            rpc::proto::UnseenChannelBufferChange {
+                channel_id: buffers[0].channel_id.to_proto(),
+                epoch: 0,
+                version: serialize_version(&text_buffers[0].version()),
+            },
+            rpc::proto::UnseenChannelBufferChange {
+                channel_id: buffers[1].channel_id.to_proto(),
+                epoch: 1,
+                version: serialize_version(&text_buffers[1].version())
+                    .into_iter()
+                    .filter(|vector| vector.replica_id
+                        == buffer_changes[1].version.first().unwrap().replica_id)
+                    .collect::<Vec<_>>(),
+            },
+            rpc::proto::UnseenChannelBufferChange {
+                channel_id: buffers[2].channel_id.to_proto(),
+                epoch: 0,
+                version: serialize_version(&text_buffers[2].version()),
+            },
+        ]
+    );
+
+    db.observe_buffer_version(
+        buffers[1].id,
+        observer_id,
+        1,
+        serialize_version(&text_buffers[1].version()).as_slice(),
+    )
+    .await
+    .unwrap();
+
+    let buffer_changes = db
+        .transaction(|tx| {
+            let buffers = &buffers;
+            async move {
+                db.unseen_channel_buffer_changes(
+                    observer_id,
+                    &[
+                        buffers[0].channel_id,
+                        buffers[1].channel_id,
+                        buffers[2].channel_id,
+                    ],
+                    &*tx,
+                )
+                .await
+            }
+        })
+        .await
+        .unwrap();
+
+    assert_eq!(
+        buffer_changes,
+        [
+            rpc::proto::UnseenChannelBufferChange {
+                channel_id: buffers[0].channel_id.to_proto(),
+                epoch: 0,
+                version: serialize_version(&text_buffers[0].version()),
+            },
+            rpc::proto::UnseenChannelBufferChange {
+                channel_id: buffers[2].channel_id.to_proto(),
+                epoch: 0,
+                version: serialize_version(&text_buffers[2].version()),
+            },
+        ]
+    );
+
+    // Observe an earlier version of the buffer.
+    db.observe_buffer_version(
+        buffers[1].id,
+        observer_id,
+        1,
+        &[rpc::proto::VectorClockEntry {
+            replica_id: 0,
+            timestamp: 0,
+        }],
+    )
+    .await
+    .unwrap();
+
+    let buffer_changes = db
+        .transaction(|tx| {
+            let buffers = &buffers;
+            async move {
+                db.unseen_channel_buffer_changes(
+                    observer_id,
+                    &[
+                        buffers[0].channel_id,
+                        buffers[1].channel_id,
+                        buffers[2].channel_id,
+                    ],
+                    &*tx,
+                )
+                .await
+            }
+        })
+        .await
+        .unwrap();
+
+    assert_eq!(
+        buffer_changes,
+        [
+            rpc::proto::UnseenChannelBufferChange {
+                channel_id: buffers[0].channel_id.to_proto(),
+                epoch: 0,
+                version: serialize_version(&text_buffers[0].version()),
+            },
+            rpc::proto::UnseenChannelBufferChange {
+                channel_id: buffers[2].channel_id.to_proto(),
+                epoch: 0,
+                version: serialize_version(&text_buffers[2].version()),
+            },
+        ]
+    );
+}
+
+async fn update_buffer(
+    channel_id: ChannelId,
+    user_id: UserId,
+    db: &Database,
+    operations: Vec<text::Operation>,
+) {
+    let operations = operations
+        .into_iter()
+        .map(|op| proto::serialize_operation(&language::Operation::Buffer(op)))
+        .collect::<Vec<_>>();
+    db.update_channel_buffer(channel_id, user_id, &operations)
+        .await
+        .unwrap();
+}
+
+fn assert_operations(
+    operations: &[buffer_operation::Model],
+    expected: &[(BufferId, i32, &text::Buffer)],
+) {
+    let actual = operations
+        .iter()
+        .map(|op| buffer_operation::Model {
+            buffer_id: op.buffer_id,
+            epoch: op.epoch,
+            lamport_timestamp: op.lamport_timestamp,
+            replica_id: op.replica_id,
+            value: vec![],
+        })
+        .collect::<Vec<_>>();
+    let expected = expected
+        .iter()
+        .map(|(buffer_id, epoch, buffer)| buffer_operation::Model {
+            buffer_id: *buffer_id,
+            epoch: *epoch,
+            lamport_timestamp: buffer.lamport_clock.value as i32 - 1,
+            replica_id: buffer.replica_id() as i32,
+            value: vec![],
+        })
+        .collect::<Vec<_>>();
+    assert_eq!(actual, expected, "unexpected operations")
+}

crates/collab/src/db/tests/message_tests.rs

@@ -57,3 +57,188 @@ async fn test_channel_message_nonces(db: &Arc<Database>) {
     assert_eq!(msg1_id, msg3_id);
     assert_eq!(msg2_id, msg4_id);
 }
+
+test_both_dbs!(
+    test_channel_message_new_notification,
+    test_channel_message_new_notification_postgres,
+    test_channel_message_new_notification_sqlite
+);
+
+async fn test_channel_message_new_notification(db: &Arc<Database>) {
+    let user = db
+        .create_user(
+            "user_a@example.com",
+            false,
+            NewUserParams {
+                github_login: "user_a".into(),
+                github_user_id: 1,
+                invite_count: 0,
+            },
+        )
+        .await
+        .unwrap()
+        .user_id;
+    let observer = db
+        .create_user(
+            "user_b@example.com",
+            false,
+            NewUserParams {
+                github_login: "user_b".into(),
+                github_user_id: 1,
+                invite_count: 0,
+            },
+        )
+        .await
+        .unwrap()
+        .user_id;
+
+    let channel_1 = db
+        .create_channel("channel", None, "room", user)
+        .await
+        .unwrap();
+
+    let channel_2 = db
+        .create_channel("channel-2", None, "room", user)
+        .await
+        .unwrap();
+
+    db.invite_channel_member(channel_1, observer, user, false)
+        .await
+        .unwrap();
+
+    db.respond_to_channel_invite(channel_1, observer, true)
+        .await
+        .unwrap();
+
+    db.invite_channel_member(channel_2, observer, user, false)
+        .await
+        .unwrap();
+
+    db.respond_to_channel_invite(channel_2, observer, true)
+        .await
+        .unwrap();
+
+    let owner_id = db.create_server("test").await.unwrap().0 as u32;
+    let user_connection_id = rpc::ConnectionId { owner_id, id: 0 };
+
+    db.join_channel_chat(channel_1, user_connection_id, user)
+        .await
+        .unwrap();
+
+    let _ = db
+        .create_channel_message(channel_1, user, "1_1", OffsetDateTime::now_utc(), 1)
+        .await
+        .unwrap();
+
+    let (second_message, _, _) = db
+        .create_channel_message(channel_1, user, "1_2", OffsetDateTime::now_utc(), 2)
+        .await
+        .unwrap();
+
+    let (third_message, _, _) = db
+        .create_channel_message(channel_1, user, "1_3", OffsetDateTime::now_utc(), 3)
+        .await
+        .unwrap();
+
+    db.join_channel_chat(channel_2, user_connection_id, user)
+        .await
+        .unwrap();
+
+    let (fourth_message, _, _) = db
+        .create_channel_message(channel_2, user, "2_1", OffsetDateTime::now_utc(), 4)
+        .await
+        .unwrap();
+
+    // Check that observer has new messages
+    let unseen_messages = db
+        .transaction(|tx| async move {
+            db.unseen_channel_messages(observer, &[channel_1, channel_2], &*tx)
+                .await
+        })
+        .await
+        .unwrap();
+
+    assert_eq!(
+        unseen_messages,
+        [
+            rpc::proto::UnseenChannelMessage {
+                channel_id: channel_1.to_proto(),
+                message_id: third_message.to_proto(),
+            },
+            rpc::proto::UnseenChannelMessage {
+                channel_id: channel_2.to_proto(),
+                message_id: fourth_message.to_proto(),
+            },
+        ]
+    );
+
+    // Observe the second message
+    db.observe_channel_message(channel_1, observer, second_message)
+        .await
+        .unwrap();
+
+    // Make sure the observer still has a new message
+    let unseen_messages = db
+        .transaction(|tx| async move {
+            db.unseen_channel_messages(observer, &[channel_1, channel_2], &*tx)
+                .await
+        })
+        .await
+        .unwrap();
+    assert_eq!(
+        unseen_messages,
+        [
+            rpc::proto::UnseenChannelMessage {
+                channel_id: channel_1.to_proto(),
+                message_id: third_message.to_proto(),
+            },
+            rpc::proto::UnseenChannelMessage {
+                channel_id: channel_2.to_proto(),
+                message_id: fourth_message.to_proto(),
+            },
+        ]
+    );
+
+    // Observe the third message,
+    db.observe_channel_message(channel_1, observer, third_message)
+        .await
+        .unwrap();
+
+    // Make sure the observer does not have a new method
+    let unseen_messages = db
+        .transaction(|tx| async move {
+            db.unseen_channel_messages(observer, &[channel_1, channel_2], &*tx)
+                .await
+        })
+        .await
+        .unwrap();
+
+    assert_eq!(
+        unseen_messages,
+        [rpc::proto::UnseenChannelMessage {
+            channel_id: channel_2.to_proto(),
+            message_id: fourth_message.to_proto(),
+        }]
+    );
+
+    // Observe the second message again, should not regress our observed state
+    db.observe_channel_message(channel_1, observer, second_message)
+        .await
+        .unwrap();
+
+    // Make sure the observer does not have a new message
+    let unseen_messages = db
+        .transaction(|tx| async move {
+            db.unseen_channel_messages(observer, &[channel_1, channel_2], &*tx)
+                .await
+        })
+        .await
+        .unwrap();
+    assert_eq!(
+        unseen_messages,
+        [rpc::proto::UnseenChannelMessage {
+            channel_id: channel_2.to_proto(),
+            message_id: fourth_message.to_proto(),
+        }]
+    );
+}

crates/collab/src/rpc.rs

@@ -3,8 +3,8 @@ mod connection_pool;
 use crate::{
     auth,
     db::{
-        self, ChannelId, ChannelsForUser, Database, MessageId, ProjectId, RoomId, ServerId, User,
-        UserId,
+        self, BufferId, ChannelId, ChannelsForUser, Database, MessageId, ProjectId, RoomId,
+        ServerId, User, UserId,
     },
     executor::Executor,
     AppState, Result,
@@ -38,8 +38,8 @@ use lazy_static::lazy_static;
 use prometheus::{register_int_gauge, IntGauge};
 use rpc::{
     proto::{
-        self, Ack, AddChannelBufferCollaborator, AnyTypedEnvelope, ChannelEdge, EntityMessage,
-        EnvelopedMessage, LiveKitConnectionInfo, RequestMessage,
+        self, Ack, AnyTypedEnvelope, ChannelEdge, EntityMessage, EnvelopedMessage,
+        LiveKitConnectionInfo, RequestMessage, UpdateChannelBufferCollaborators,
     },
     Connection, ConnectionId, Peer, Receipt, TypedEnvelope,
 };
@@ -274,7 +274,9 @@ impl Server {
             .add_message_handler(unfollow)
             .add_message_handler(update_followers)
             .add_message_handler(update_diff_base)
-            .add_request_handler(get_private_user_info);
+            .add_request_handler(get_private_user_info)
+            .add_message_handler(acknowledge_channel_message)
+            .add_message_handler(acknowledge_buffer_version);
 
         Arc::new(server)
     }
@@ -313,9 +315,16 @@ impl Server {
                             .trace_err()
                         {
                             for connection_id in refreshed_channel_buffer.connection_ids {
-                                for message in &refreshed_channel_buffer.removed_collaborators {
-                                    peer.send(connection_id, message.clone()).trace_err();
-                                }
+                                peer.send(
+                                    connection_id,
+                                    proto::UpdateChannelBufferCollaborators {
+                                        channel_id: channel_id.to_proto(),
+                                        collaborators: refreshed_channel_buffer
+                                            .collaborators
+                                            .clone(),
+                                    },
+                                )
+                                .trace_err();
                             }
                         }
                     }
@@ -1883,94 +1892,94 @@ async fn follow(
     response: Response<proto::Follow>,
     session: Session,
 ) -> Result<()> {
-    let project_id = ProjectId::from_proto(request.project_id);
+    let room_id = RoomId::from_proto(request.room_id);
+    let project_id = request.project_id.map(ProjectId::from_proto);
     let leader_id = request
         .leader_id
         .ok_or_else(|| anyhow!("invalid leader id"))?
         .into();
     let follower_id = session.connection_id;
 
-    {
-        let project_connection_ids = session
-            .db()
-            .await
-            .project_connection_ids(project_id, session.connection_id)
-            .await?;
+    session
+        .db()
+        .await
+        .check_room_participants(room_id, leader_id, session.connection_id)
+        .await?;
 
-        if !project_connection_ids.contains(&leader_id) {
-            Err(anyhow!("no such peer"))?;
-        }
-    }
-
-    let mut response_payload = session
+    let response_payload = session
         .peer
         .forward_request(session.connection_id, leader_id, request)
         .await?;
-    response_payload
-        .views
-        .retain(|view| view.leader_id != Some(follower_id.into()));
     response.send(response_payload)?;
 
-    let room = session
-        .db()
-        .await
-        .follow(project_id, leader_id, follower_id)
-        .await?;
-    room_updated(&room, &session.peer);
+    if let Some(project_id) = project_id {
+        let room = session
+            .db()
+            .await
+            .follow(room_id, project_id, leader_id, follower_id)
+            .await?;
+        room_updated(&room, &session.peer);
+    }
 
     Ok(())
 }
 
 async fn unfollow(request: proto::Unfollow, session: Session) -> Result<()> {
-    let project_id = ProjectId::from_proto(request.project_id);
+    let room_id = RoomId::from_proto(request.room_id);
+    let project_id = request.project_id.map(ProjectId::from_proto);
     let leader_id = request
         .leader_id
         .ok_or_else(|| anyhow!("invalid leader id"))?
         .into();
     let follower_id = session.connection_id;
 
-    if !session
+    session
         .db()
         .await
-        .project_connection_ids(project_id, session.connection_id)
-        .await?
-        .contains(&leader_id)
-    {
-        Err(anyhow!("no such peer"))?;
-    }
+        .check_room_participants(room_id, leader_id, session.connection_id)
+        .await?;
 
     session
         .peer
         .forward_send(session.connection_id, leader_id, request)?;
 
-    let room = session
-        .db()
-        .await
-        .unfollow(project_id, leader_id, follower_id)
-        .await?;
-    room_updated(&room, &session.peer);
+    if let Some(project_id) = project_id {
+        let room = session
+            .db()
+            .await
+            .unfollow(room_id, project_id, leader_id, follower_id)
+            .await?;
+        room_updated(&room, &session.peer);
+    }
 
     Ok(())
 }
 
 async fn update_followers(request: proto::UpdateFollowers, session: Session) -> Result<()> {
-    let project_id = ProjectId::from_proto(request.project_id);
-    let project_connection_ids = session
-        .db
-        .lock()
-        .await
-        .project_connection_ids(project_id, session.connection_id)
-        .await?;
+    let room_id = RoomId::from_proto(request.room_id);
+    let database = session.db.lock().await;
 
-    let leader_id = request.variant.as_ref().and_then(|variant| match variant {
-        proto::update_followers::Variant::CreateView(payload) => payload.leader_id,
+    let connection_ids = if let Some(project_id) = request.project_id {
+        let project_id = ProjectId::from_proto(project_id);
+        database
+            .project_connection_ids(project_id, session.connection_id)
+            .await?
+    } else {
+        database
+            .room_connection_ids(room_id, session.connection_id)
+            .await?
+    };
+
+    // For now, don't send view update messages back to that view's current leader.
+    let connection_id_to_omit = request.variant.as_ref().and_then(|variant| match variant {
         proto::update_followers::Variant::UpdateView(payload) => payload.leader_id,
-        proto::update_followers::Variant::UpdateActiveView(payload) => payload.leader_id,
+        _ => None,
     });
+
     for follower_peer_id in request.follower_ids.iter().copied() {
         let follower_connection_id = follower_peer_id.into();
-        if project_connection_ids.contains(&follower_connection_id)
-            && Some(follower_peer_id) != leader_id
+        if Some(follower_peer_id) != connection_id_to_omit
+            && connection_ids.contains(&follower_connection_id)
         {
             session.peer.forward_send(
                 session.connection_id,
@@ -2561,6 +2570,8 @@ async fn respond_to_channel_invite(
                         name: channel.name,
                     }),
             );
+        update.unseen_channel_messages = result.channel_messages;
+        update.unseen_channel_buffer_changes = result.unseen_buffer_changes;
         update.insert_edge = result.channels.edges;
         update
             .channel_participants
@@ -2658,18 +2669,12 @@ async fn join_channel_buffer(
         .join_channel_buffer(channel_id, session.user_id, session.connection_id)
         .await?;
 
-    let replica_id = open_response.replica_id;
     let collaborators = open_response.collaborators.clone();
-
     response.send(open_response)?;
 
-    let update = AddChannelBufferCollaborator {
+    let update = UpdateChannelBufferCollaborators {
         channel_id: channel_id.to_proto(),
-        collaborator: Some(proto::Collaborator {
-            user_id: session.user_id.to_proto(),
-            peer_id: Some(session.connection_id.into()),
-            replica_id,
-        }),
+        collaborators: collaborators.clone(),
     };
     channel_buffer_updated(
         session.connection_id,
@@ -2690,7 +2695,7 @@ async fn update_channel_buffer(
     let db = session.db().await;
     let channel_id = ChannelId::from_proto(request.channel_id);
 
-    let collaborators = db
+    let (collaborators, non_collaborators, epoch, version) = db
         .update_channel_buffer(channel_id, session.user_id, &request.operations)
         .await?;
 
@@ -2703,6 +2708,29 @@ async fn update_channel_buffer(
         },
         &session.peer,
     );
+
+    let pool = &*session.connection_pool().await;
+
+    broadcast(
+        None,
+        non_collaborators
+            .iter()
+            .flat_map(|user_id| pool.user_connection_ids(*user_id)),
+        |peer_id| {
+            session.peer.send(
+                peer_id.into(),
+                proto::UpdateChannels {
+                    unseen_channel_buffer_changes: vec![proto::UnseenChannelBufferChange {
+                        channel_id: channel_id.to_proto(),
+                        epoch: epoch as u64,
+                        version: version.clone(),
+                    }],
+                    ..Default::default()
+                },
+            )
+        },
+    );
+
     Ok(())
 }
 
@@ -2716,8 +2744,8 @@ async fn rejoin_channel_buffers(
         .rejoin_channel_buffers(&request.buffers, session.user_id, session.connection_id)
         .await?;
 
-    for buffer in &buffers {
-        let collaborators_to_notify = buffer
+    for rejoined_buffer in &buffers {
+        let collaborators_to_notify = rejoined_buffer
             .buffer
             .collaborators
             .iter()
@@ -2725,10 +2753,9 @@ async fn rejoin_channel_buffers(
         channel_buffer_updated(
             session.connection_id,
             collaborators_to_notify,
-            &proto::UpdateChannelBufferCollaborator {
-                channel_id: buffer.buffer.channel_id,
-                old_peer_id: Some(buffer.old_connection_id.into()),
-                new_peer_id: Some(session.connection_id.into()),
+            &proto::UpdateChannelBufferCollaborators {
+                channel_id: rejoined_buffer.buffer.channel_id,
+                collaborators: rejoined_buffer.buffer.collaborators.clone(),
             },
             &session.peer,
         );
@@ -2749,7 +2776,7 @@ async fn leave_channel_buffer(
     let db = session.db().await;
     let channel_id = ChannelId::from_proto(request.channel_id);
 
-    let collaborators_to_notify = db
+    let left_buffer = db
         .leave_channel_buffer(channel_id, session.connection_id)
         .await?;
 
@@ -2757,10 +2784,10 @@ async fn leave_channel_buffer(
 
     channel_buffer_updated(
         session.connection_id,
-        collaborators_to_notify,
-        &proto::RemoveChannelBufferCollaborator {
+        left_buffer.connections,
+        &proto::UpdateChannelBufferCollaborators {
             channel_id: channel_id.to_proto(),
-            peer_id: Some(session.connection_id.into()),
+            collaborators: left_buffer.collaborators,
         },
         &session.peer,
     );
@@ -2799,7 +2826,7 @@ async fn send_channel_message(
         .ok_or_else(|| anyhow!("nonce can't be blank"))?;
 
     let channel_id = ChannelId::from_proto(request.channel_id);
-    let (message_id, connection_ids) = session
+    let (message_id, connection_ids, non_participants) = session
         .db()
         .await
         .create_channel_message(
@@ -2829,6 +2856,27 @@ async fn send_channel_message(
     response.send(proto::SendChannelMessageResponse {
         message: Some(message),
     })?;
+
+    let pool = &*session.connection_pool().await;
+    broadcast(
+        None,
+        non_participants
+            .iter()
+            .flat_map(|user_id| pool.user_connection_ids(*user_id)),
+        |peer_id| {
+            session.peer.send(
+                peer_id.into(),
+                proto::UpdateChannels {
+                    unseen_channel_messages: vec![proto::UnseenChannelMessage {
+                        channel_id: channel_id.to_proto(),
+                        message_id: message_id.to_proto(),
+                    }],
+                    ..Default::default()
+                },
+            )
+        },
+    );
+
     Ok(())
 }
 
@@ -2851,6 +2899,38 @@ async fn remove_channel_message(
     Ok(())
 }
 
+async fn acknowledge_channel_message(
+    request: proto::AckChannelMessage,
+    session: Session,
+) -> Result<()> {
+    let channel_id = ChannelId::from_proto(request.channel_id);
+    let message_id = MessageId::from_proto(request.message_id);
+    session
+        .db()
+        .await
+        .observe_channel_message(channel_id, session.user_id, message_id)
+        .await?;
+    Ok(())
+}
+
+async fn acknowledge_buffer_version(
+    request: proto::AckBufferOperation,
+    session: Session,
+) -> Result<()> {
+    let buffer_id = BufferId::from_proto(request.buffer_id);
+    session
+        .db()
+        .await
+        .observe_buffer_version(
+            buffer_id,
+            session.user_id,
+            request.epoch as i32,
+            &request.version,
+        )
+        .await?;
+    Ok(())
+}
+
 async fn join_channel_chat(
     request: proto::JoinChannelChat,
     response: Response<proto::JoinChannelChat>,
@@ -2986,6 +3066,8 @@ fn build_initial_channels_update(
         });
     }
 
+    update.unseen_channel_buffer_changes = channels.unseen_buffer_changes;
+    update.unseen_channel_messages = channels.channel_messages;
     update.insert_edge = channels.channels.edges;
 
     for (channel_id, participants) in channels.channel_participants {
@@ -3235,13 +3317,13 @@ async fn leave_channel_buffers_for_session(session: &Session) -> Result<()> {
         .leave_channel_buffers(session.connection_id)
         .await?;
 
-    for (channel_id, connections) in left_channel_buffers {
+    for left_buffer in left_channel_buffers {
         channel_buffer_updated(
             session.connection_id,
-            connections,
-            &proto::RemoveChannelBufferCollaborator {
-                channel_id: channel_id.to_proto(),
-                peer_id: Some(session.connection_id.into()),
+            left_buffer.connections,
+            &proto::UpdateChannelBufferCollaborators {
+                channel_id: left_buffer.channel_id.to_proto(),
+                collaborators: left_buffer.collaborators,
             },
             &session.peer,
         );

crates/collab/src/tests.rs

@@ -4,6 +4,7 @@ use gpui::{ModelHandle, TestAppContext};
 mod channel_buffer_tests;
 mod channel_message_tests;
 mod channel_tests;
+mod following_tests;
 mod integration_tests;
 mod random_channel_buffer_tests;
 mod random_project_collaboration_tests;

crates/collab/src/tests/channel_buffer_tests.rs

@@ -3,15 +3,17 @@ use crate::{
     tests::TestServer,
 };
 use call::ActiveCall;
-use channel::Channel;
-use client::UserId;
+use channel::{Channel, ACKNOWLEDGE_DEBOUNCE_INTERVAL};
+use client::ParticipantIndex;
+use client::{Collaborator, UserId};
 use collab_ui::channel_view::ChannelView;
 use collections::HashMap;
+use editor::{Anchor, Editor, ToOffset};
 use futures::future;
-use gpui::{executor::Deterministic, ModelHandle, TestAppContext};
-use rpc::{proto, RECEIVE_TIMEOUT};
+use gpui::{executor::Deterministic, ModelHandle, TestAppContext, ViewContext};
+use rpc::{proto::PeerId, RECEIVE_TIMEOUT};
 use serde_json::json;
-use std::sync::Arc;
+use std::{ops::Range, sync::Arc};
 
 #[gpui::test]
 async fn test_core_channel_buffers(
@@ -100,7 +102,7 @@ async fn test_core_channel_buffers(
     channel_buffer_b.read_with(cx_b, |buffer, _| {
         assert_collaborators(
             &buffer.collaborators(),
-            &[client_b.user_id(), client_a.user_id()],
+            &[client_a.user_id(), client_b.user_id()],
         );
     });
 
@@ -120,10 +122,10 @@ async fn test_core_channel_buffers(
 }
 
 #[gpui::test]
-async fn test_channel_buffer_replica_ids(
+async fn test_channel_notes_participant_indices(
     deterministic: Arc<Deterministic>,
-    cx_a: &mut TestAppContext,
-    cx_b: &mut TestAppContext,
+    mut cx_a: &mut TestAppContext,
+    mut cx_b: &mut TestAppContext,
     cx_c: &mut TestAppContext,
 ) {
     deterministic.forbid_parking();
@@ -132,6 +134,13 @@ async fn test_channel_buffer_replica_ids(
     let client_b = server.create_client(cx_b, "user_b").await;
     let client_c = server.create_client(cx_c, "user_c").await;
 
+    let active_call_a = cx_a.read(ActiveCall::global);
+    let active_call_b = cx_b.read(ActiveCall::global);
+
+    cx_a.update(editor::init);
+    cx_b.update(editor::init);
+    cx_c.update(editor::init);
+
     let channel_id = server
         .make_channel(
             "the-channel",
@@ -141,140 +150,173 @@ async fn test_channel_buffer_replica_ids(
         )
         .await;
 
-    let active_call_a = cx_a.read(ActiveCall::global);
-    let active_call_b = cx_b.read(ActiveCall::global);
-    let active_call_c = cx_c.read(ActiveCall::global);
-
-    // Clients A and B join a channel.
-    active_call_a
-        .update(cx_a, |call, cx| call.join_channel(channel_id, cx))
-        .await
-        .unwrap();
-    active_call_b
-        .update(cx_b, |call, cx| call.join_channel(channel_id, cx))
-        .await
-        .unwrap();
-
-    // Clients A, B, and C join a channel buffer
-    // C first so that the replica IDs in the project and the channel buffer are different
-    let channel_buffer_c = client_c
-        .channel_store()
-        .update(cx_c, |store, cx| store.open_channel_buffer(channel_id, cx))
-        .await
-        .unwrap();
-    let channel_buffer_b = client_b
-        .channel_store()
-        .update(cx_b, |store, cx| store.open_channel_buffer(channel_id, cx))
-        .await
-        .unwrap();
-    let channel_buffer_a = client_a
-        .channel_store()
-        .update(cx_a, |store, cx| store.open_channel_buffer(channel_id, cx))
-        .await
-        .unwrap();
-
-    // Client B shares a project
-    client_b
+    client_a
         .fs()
-        .insert_tree("/dir", json!({ "file.txt": "contents" }))
+        .insert_tree("/root", json!({"file.txt": "123"}))
         .await;
-    let (project_b, _) = client_b.build_local_project("/dir", cx_b).await;
-    let shared_project_id = active_call_b
-        .update(cx_b, |call, cx| call.share_project(project_b.clone(), cx))
+    let (project_a, worktree_id_a) = client_a.build_local_project("/root", cx_a).await;
+    let project_b = client_b.build_empty_local_project(cx_b);
+    let project_c = client_c.build_empty_local_project(cx_c);
+    let workspace_a = client_a.build_workspace(&project_a, cx_a).root(cx_a);
+    let workspace_b = client_b.build_workspace(&project_b, cx_b).root(cx_b);
+    let workspace_c = client_c.build_workspace(&project_c, cx_c).root(cx_c);
+
+    // Clients A, B, and C open the channel notes
+    let channel_view_a = cx_a
+        .update(|cx| ChannelView::open(channel_id, workspace_a.clone(), cx))
+        .await
+        .unwrap();
+    let channel_view_b = cx_b
+        .update(|cx| ChannelView::open(channel_id, workspace_b.clone(), cx))
+        .await
+        .unwrap();
+    let channel_view_c = cx_c
+        .update(|cx| ChannelView::open(channel_id, workspace_c.clone(), cx))
         .await
         .unwrap();
 
-    // Client A joins the project
-    let project_a = client_a.build_remote_project(shared_project_id, cx_a).await;
+    // Clients A, B, and C all insert and select some text
+    channel_view_a.update(cx_a, |notes, cx| {
+        notes.editor.update(cx, |editor, cx| {
+            editor.insert("a", cx);
+            editor.change_selections(None, cx, |selections| {
+                selections.select_ranges(vec![0..1]);
+            });
+        });
+    });
     deterministic.run_until_parked();
-
-    // Client C is in a separate project.
-    client_c.fs().insert_tree("/dir", json!({})).await;
-    let (separate_project_c, _) = client_c.build_local_project("/dir", cx_c).await;
-
-    // Note that each user has a different replica id in the projects vs the
-    // channel buffer.
-    channel_buffer_a.read_with(cx_a, |channel_buffer, cx| {
-        assert_eq!(project_a.read(cx).replica_id(), 1);
-        assert_eq!(channel_buffer.buffer().read(cx).replica_id(), 2);
+    channel_view_b.update(cx_b, |notes, cx| {
+        notes.editor.update(cx, |editor, cx| {
+            editor.move_down(&Default::default(), cx);
+            editor.insert("b", cx);
+            editor.change_selections(None, cx, |selections| {
+                selections.select_ranges(vec![1..2]);
+            });
+        });
     });
-    channel_buffer_b.read_with(cx_b, |channel_buffer, cx| {
-        assert_eq!(project_b.read(cx).replica_id(), 0);
-        assert_eq!(channel_buffer.buffer().read(cx).replica_id(), 1);
-    });
-    channel_buffer_c.read_with(cx_c, |channel_buffer, cx| {
-        // C is not in the project
-        assert_eq!(channel_buffer.buffer().read(cx).replica_id(), 0);
+    deterministic.run_until_parked();
+    channel_view_c.update(cx_c, |notes, cx| {
+        notes.editor.update(cx, |editor, cx| {
+            editor.move_down(&Default::default(), cx);
+            editor.insert("c", cx);
+            editor.change_selections(None, cx, |selections| {
+                selections.select_ranges(vec![2..3]);
+            });
+        });
     });
 
-    let channel_window_a =
-        cx_a.add_window(|cx| ChannelView::new(project_a.clone(), channel_buffer_a.clone(), cx));
-    let channel_window_b =
-        cx_b.add_window(|cx| ChannelView::new(project_b.clone(), channel_buffer_b.clone(), cx));
-    let channel_window_c = cx_c.add_window(|cx| {
-        ChannelView::new(separate_project_c.clone(), channel_buffer_c.clone(), cx)
+    // Client A sees clients B and C without assigned colors, because they aren't
+    // in a call together.
+    deterministic.run_until_parked();
+    channel_view_a.update(cx_a, |notes, cx| {
+        notes.editor.update(cx, |editor, cx| {
+            assert_remote_selections(editor, &[(None, 1..2), (None, 2..3)], cx);
+        });
     });
 
-    let channel_view_a = channel_window_a.root(cx_a);
-    let channel_view_b = channel_window_b.root(cx_b);
-    let channel_view_c = channel_window_c.root(cx_c);
+    // Clients A and B join the same call.
+    for (call, cx) in [(&active_call_a, &mut cx_a), (&active_call_b, &mut cx_b)] {
+        call.update(*cx, |call, cx| call.join_channel(channel_id, cx))
+            .await
+            .unwrap();
+    }
 
-    // For clients A and B, the replica ids in the channel buffer are mapped
-    // so that they match the same users' replica ids in their shared project.
-    channel_view_a.read_with(cx_a, |view, cx| {
-        assert_eq!(
-            view.editor.read(cx).replica_id_map().unwrap(),
-            &[(1, 0), (2, 1)].into_iter().collect::<HashMap<_, _>>()
-        );
+    // Clients A and B see each other with two different assigned colors. Client C
+    // still doesn't have a color.
+    deterministic.run_until_parked();
+    channel_view_a.update(cx_a, |notes, cx| {
+        notes.editor.update(cx, |editor, cx| {
+            assert_remote_selections(
+                editor,
+                &[(Some(ParticipantIndex(1)), 1..2), (None, 2..3)],
+                cx,
+            );
+        });
     });
-    channel_view_b.read_with(cx_b, |view, cx| {
-        assert_eq!(
-            view.editor.read(cx).replica_id_map().unwrap(),
-            &[(1, 0), (2, 1)].into_iter().collect::<HashMap<u16, u16>>(),
-        )
+    channel_view_b.update(cx_b, |notes, cx| {
+        notes.editor.update(cx, |editor, cx| {
+            assert_remote_selections(
+                editor,
+                &[(Some(ParticipantIndex(0)), 0..1), (None, 2..3)],
+                cx,
+            );
+        });
     });
 
-    // Client C only sees themself, as they're not part of any shared project
-    channel_view_c.read_with(cx_c, |view, cx| {
-        assert_eq!(
-            view.editor.read(cx).replica_id_map().unwrap(),
-            &[(0, 0)].into_iter().collect::<HashMap<u16, u16>>(),
-        );
-    });
-
-    // Client C joins the project that clients A and B are in.
-    active_call_c
-        .update(cx_c, |call, cx| call.join_channel(channel_id, cx))
+    // Client A shares a project, and client B joins.
+    let project_id = active_call_a
+        .update(cx_a, |call, cx| call.share_project(project_a.clone(), cx))
         .await
         .unwrap();
-    let project_c = client_c.build_remote_project(shared_project_id, cx_c).await;
-    deterministic.run_until_parked();
-    project_c.read_with(cx_c, |project, _| {
-        assert_eq!(project.replica_id(), 2);
-    });
+    let project_b = client_b.build_remote_project(project_id, cx_b).await;
+    let workspace_b = client_b.build_workspace(&project_b, cx_b).root(cx_b);
 
-    // For clients A and B, client C's replica id in the channel buffer is
-    // now mapped to their replica id in the shared project.
-    channel_view_a.read_with(cx_a, |view, cx| {
-        assert_eq!(
-            view.editor.read(cx).replica_id_map().unwrap(),
-            &[(1, 0), (2, 1), (0, 2)]
-                .into_iter()
-                .collect::<HashMap<_, _>>()
-        );
+    // Clients A and B open the same file.
+    let editor_a = workspace_a
+        .update(cx_a, |workspace, cx| {
+            workspace.open_path((worktree_id_a, "file.txt"), None, true, cx)
+        })
+        .await
+        .unwrap()
+        .downcast::<Editor>()
+        .unwrap();
+    let editor_b = workspace_b
+        .update(cx_b, |workspace, cx| {
+            workspace.open_path((worktree_id_a, "file.txt"), None, true, cx)
+        })
+        .await
+        .unwrap()
+        .downcast::<Editor>()
+        .unwrap();
+
+    editor_a.update(cx_a, |editor, cx| {
+        editor.change_selections(None, cx, |selections| {
+            selections.select_ranges(vec![0..1]);
+        });
     });
-    channel_view_b.read_with(cx_b, |view, cx| {
-        assert_eq!(
-            view.editor.read(cx).replica_id_map().unwrap(),
-            &[(1, 0), (2, 1), (0, 2)]
-                .into_iter()
-                .collect::<HashMap<_, _>>(),
-        )
+    editor_b.update(cx_b, |editor, cx| {
+        editor.change_selections(None, cx, |selections| {
+            selections.select_ranges(vec![2..3]);
+        });
+    });
+    deterministic.run_until_parked();
+
+    // Clients A and B see each other with the same colors as in the channel notes.
+    editor_a.update(cx_a, |editor, cx| {
+        assert_remote_selections(editor, &[(Some(ParticipantIndex(1)), 2..3)], cx);
+    });
+    editor_b.update(cx_b, |editor, cx| {
+        assert_remote_selections(editor, &[(Some(ParticipantIndex(0)), 0..1)], cx);
     });
 }
 
+#[track_caller]
+fn assert_remote_selections(
+    editor: &mut Editor,
+    expected_selections: &[(Option<ParticipantIndex>, Range<usize>)],
+    cx: &mut ViewContext<Editor>,
+) {
+    let snapshot = editor.snapshot(cx);
+    let range = Anchor::min()..Anchor::max();
+    let remote_selections = snapshot
+        .remote_selections_in_range(&range, editor.collaboration_hub().unwrap(), cx)
+        .map(|s| {
+            let start = s.selection.start.to_offset(&snapshot.buffer_snapshot);
+            let end = s.selection.end.to_offset(&snapshot.buffer_snapshot);
+            (s.participant_index, start..end)
+        })
+        .collect::<Vec<_>>();
+    assert_eq!(
+        remote_selections, expected_selections,
+        "incorrect remote selections"
+    );
+}
+
 #[gpui::test]
-async fn test_reopen_channel_buffer(deterministic: Arc<Deterministic>, cx_a: &mut TestAppContext) {
+async fn test_multiple_handles_to_channel_buffer(
+    deterministic: Arc<Deterministic>,
+    cx_a: &mut TestAppContext,
+) {
     deterministic.forbid_parking();
     let mut server = TestServer::start(&deterministic).await;
     let client_a = server.create_client(cx_a, "user_a").await;
@@ -368,10 +410,7 @@ async fn test_channel_buffer_disconnect(
     channel_buffer_a.update(cx_a, |buffer, _| {
         assert_eq!(
             buffer.channel().as_ref(),
-            &Channel {
-                id: channel_id,
-                name: "the-channel".to_string()
-            }
+            &channel(channel_id, "the-channel")
         );
         assert!(!buffer.is_connected());
     });
@@ -396,15 +435,21 @@ async fn test_channel_buffer_disconnect(
     channel_buffer_b.update(cx_b, |buffer, _| {
         assert_eq!(
             buffer.channel().as_ref(),
-            &Channel {
-                id: channel_id,
-                name: "the-channel".to_string()
-            }
+            &channel(channel_id, "the-channel")
         );
         assert!(!buffer.is_connected());
     });
 }
 
+fn channel(id: u64, name: &'static str) -> Channel {
+    Channel {
+        id,
+        name: name.to_string(),
+        unseen_note_version: None,
+        unseen_message_id: None,
+    }
+}
+
 #[gpui::test]
 async fn test_rejoin_channel_buffer(
     deterministic: Arc<Deterministic>,
@@ -565,26 +610,284 @@ async fn test_channel_buffers_and_server_restarts(
 
     channel_buffer_a.read_with(cx_a, |buffer_a, _| {
         channel_buffer_b.read_with(cx_b, |buffer_b, _| {
-            assert_eq!(
-                buffer_a
-                    .collaborators()
-                    .iter()
-                    .map(|c| c.user_id)
-                    .collect::<Vec<_>>(),
-                vec![client_a.user_id().unwrap(), client_b.user_id().unwrap()]
+            assert_collaborators(
+                buffer_a.collaborators(),
+                &[client_a.user_id(), client_b.user_id()],
             );
             assert_eq!(buffer_a.collaborators(), buffer_b.collaborators());
         });
     });
 }
 
+#[gpui::test(iterations = 10)]
+async fn test_following_to_channel_notes_without_a_shared_project(
+    deterministic: Arc<Deterministic>,
+    mut cx_a: &mut TestAppContext,
+    mut cx_b: &mut TestAppContext,
+    mut cx_c: &mut TestAppContext,
+) {
+    deterministic.forbid_parking();
+    let mut server = TestServer::start(&deterministic).await;
+    let client_a = server.create_client(cx_a, "user_a").await;
+    let client_b = server.create_client(cx_b, "user_b").await;
+
+    let client_c = server.create_client(cx_c, "user_c").await;
+
+    cx_a.update(editor::init);
+    cx_b.update(editor::init);
+    cx_c.update(editor::init);
+    cx_a.update(collab_ui::channel_view::init);
+    cx_b.update(collab_ui::channel_view::init);
+    cx_c.update(collab_ui::channel_view::init);
+
+    let channel_1_id = server
+        .make_channel(
+            "channel-1",
+            None,
+            (&client_a, cx_a),
+            &mut [(&client_b, cx_b), (&client_c, cx_c)],
+        )
+        .await;
+    let channel_2_id = server
+        .make_channel(
+            "channel-2",
+            None,
+            (&client_a, cx_a),
+            &mut [(&client_b, cx_b), (&client_c, cx_c)],
+        )
+        .await;
+
+    // Clients A, B, and C join a channel.
+    let active_call_a = cx_a.read(ActiveCall::global);
+    let active_call_b = cx_b.read(ActiveCall::global);
+    let active_call_c = cx_c.read(ActiveCall::global);
+    for (call, cx) in [
+        (&active_call_a, &mut cx_a),
+        (&active_call_b, &mut cx_b),
+        (&active_call_c, &mut cx_c),
+    ] {
+        call.update(*cx, |call, cx| call.join_channel(channel_1_id, cx))
+            .await
+            .unwrap();
+    }
+    deterministic.run_until_parked();
+
+    // Clients A, B, and C all open their own unshared projects.
+    client_a.fs().insert_tree("/a", json!({})).await;
+    client_b.fs().insert_tree("/b", json!({})).await;
+    client_c.fs().insert_tree("/c", json!({})).await;
+    let (project_a, _) = client_a.build_local_project("/a", cx_a).await;
+    let (project_b, _) = client_b.build_local_project("/b", cx_b).await;
+    let (project_c, _) = client_b.build_local_project("/c", cx_c).await;
+    let workspace_a = client_a.build_workspace(&project_a, cx_a).root(cx_a);
+    let workspace_b = client_b.build_workspace(&project_b, cx_b).root(cx_b);
+    let _workspace_c = client_c.build_workspace(&project_c, cx_c).root(cx_c);
+
+    active_call_a
+        .update(cx_a, |call, cx| call.set_location(Some(&project_a), cx))
+        .await
+        .unwrap();
+
+    // Client A opens the notes for channel 1.
+    let channel_view_1_a = cx_a
+        .update(|cx| ChannelView::open(channel_1_id, workspace_a.clone(), cx))
+        .await
+        .unwrap();
+    channel_view_1_a.update(cx_a, |notes, cx| {
+        assert_eq!(notes.channel(cx).name, "channel-1");
+        notes.editor.update(cx, |editor, cx| {
+            editor.insert("Hello from A.", cx);
+            editor.change_selections(None, cx, |selections| {
+                selections.select_ranges(vec![3..4]);
+            });
+        });
+    });
+
+    // Client B follows client A.
+    workspace_b
+        .update(cx_b, |workspace, cx| {
+            workspace.follow(client_a.peer_id().unwrap(), cx).unwrap()
+        })
+        .await
+        .unwrap();
+
+    // Client B is taken to the notes for channel 1, with the same
+    // text selected as client A.
+    deterministic.run_until_parked();
+    let channel_view_1_b = workspace_b.read_with(cx_b, |workspace, cx| {
+        assert_eq!(
+            workspace.leader_for_pane(workspace.active_pane()),
+            Some(client_a.peer_id().unwrap())
+        );
+        workspace
+            .active_item(cx)
+            .expect("no active item")
+            .downcast::<ChannelView>()
+            .expect("active item is not a channel view")
+    });
+    channel_view_1_b.read_with(cx_b, |notes, cx| {
+        assert_eq!(notes.channel(cx).name, "channel-1");
+        let editor = notes.editor.read(cx);
+        assert_eq!(editor.text(cx), "Hello from A.");
+        assert_eq!(editor.selections.ranges::<usize>(cx), &[3..4]);
+    });
+
+    // Client A opens the notes for channel 2.
+    let channel_view_2_a = cx_a
+        .update(|cx| ChannelView::open(channel_2_id, workspace_a.clone(), cx))
+        .await
+        .unwrap();
+    channel_view_2_a.read_with(cx_a, |notes, cx| {
+        assert_eq!(notes.channel(cx).name, "channel-2");
+    });
+
+    // Client B is taken to the notes for channel 2.
+    deterministic.run_until_parked();
+    let channel_view_2_b = workspace_b.read_with(cx_b, |workspace, cx| {
+        assert_eq!(
+            workspace.leader_for_pane(workspace.active_pane()),
+            Some(client_a.peer_id().unwrap())
+        );
+        workspace
+            .active_item(cx)
+            .expect("no active item")
+            .downcast::<ChannelView>()
+            .expect("active item is not a channel view")
+    });
+    channel_view_2_b.read_with(cx_b, |notes, cx| {
+        assert_eq!(notes.channel(cx).name, "channel-2");
+    });
+}
+
+#[gpui::test]
+async fn test_channel_buffer_changes(
+    deterministic: Arc<Deterministic>,
+    cx_a: &mut TestAppContext,
+    cx_b: &mut TestAppContext,
+) {
+    deterministic.forbid_parking();
+    let mut server = TestServer::start(&deterministic).await;
+    let client_a = server.create_client(cx_a, "user_a").await;
+    let client_b = server.create_client(cx_b, "user_b").await;
+
+    let channel_id = server
+        .make_channel(
+            "the-channel",
+            None,
+            (&client_a, cx_a),
+            &mut [(&client_b, cx_b)],
+        )
+        .await;
+
+    let channel_buffer_a = client_a
+        .channel_store()
+        .update(cx_a, |store, cx| store.open_channel_buffer(channel_id, cx))
+        .await
+        .unwrap();
+
+    // Client A makes an edit, and client B should see that the note has changed.
+    channel_buffer_a.update(cx_a, |buffer, cx| {
+        buffer.buffer().update(cx, |buffer, cx| {
+            buffer.edit([(0..0, "1")], None, cx);
+        })
+    });
+    deterministic.run_until_parked();
+
+    let has_buffer_changed = cx_b.read(|cx| {
+        client_b
+            .channel_store()
+            .read(cx)
+            .has_channel_buffer_changed(channel_id)
+            .unwrap()
+    });
+    assert!(has_buffer_changed);
+
+    // Opening the buffer should clear the changed flag.
+    let project_b = client_b.build_empty_local_project(cx_b);
+    let workspace_b = client_b.build_workspace(&project_b, cx_b).root(cx_b);
+    let channel_view_b = cx_b
+        .update(|cx| ChannelView::open(channel_id, workspace_b.clone(), cx))
+        .await
+        .unwrap();
+    deterministic.run_until_parked();
+
+    let has_buffer_changed = cx_b.read(|cx| {
+        client_b
+            .channel_store()
+            .read(cx)
+            .has_channel_buffer_changed(channel_id)
+            .unwrap()
+    });
+    assert!(!has_buffer_changed);
+
+    // Editing the channel while the buffer is open should not show that the buffer has changed.
+    channel_buffer_a.update(cx_a, |buffer, cx| {
+        buffer.buffer().update(cx, |buffer, cx| {
+            buffer.edit([(0..0, "2")], None, cx);
+        })
+    });
+    deterministic.run_until_parked();
+
+    let has_buffer_changed = cx_b.read(|cx| {
+        client_b
+            .channel_store()
+            .read(cx)
+            .has_channel_buffer_changed(channel_id)
+            .unwrap()
+    });
+    assert!(!has_buffer_changed);
+
+    deterministic.advance_clock(ACKNOWLEDGE_DEBOUNCE_INTERVAL);
+
+    // Test that the server is tracking things correctly, and we retain our 'not changed'
+    // state across a disconnect
+    server.simulate_long_connection_interruption(client_b.peer_id().unwrap(), &deterministic);
+    let has_buffer_changed = cx_b.read(|cx| {
+        client_b
+            .channel_store()
+            .read(cx)
+            .has_channel_buffer_changed(channel_id)
+            .unwrap()
+    });
+    assert!(!has_buffer_changed);
+
+    // Closing the buffer should re-enable change tracking
+    cx_b.update(|cx| {
+        workspace_b.update(cx, |workspace, cx| {
+            workspace.close_all_items_and_panes(&Default::default(), cx)
+        });
+
+        drop(channel_view_b)
+    });
+
+    deterministic.run_until_parked();
+
+    channel_buffer_a.update(cx_a, |buffer, cx| {
+        buffer.buffer().update(cx, |buffer, cx| {
+            buffer.edit([(0..0, "3")], None, cx);
+        })
+    });
+    deterministic.run_until_parked();
+
+    let has_buffer_changed = cx_b.read(|cx| {
+        client_b
+            .channel_store()
+            .read(cx)
+            .has_channel_buffer_changed(channel_id)
+            .unwrap()
+    });
+    assert!(has_buffer_changed);
+}
+
 #[track_caller]
-fn assert_collaborators(collaborators: &[proto::Collaborator], ids: &[Option<UserId>]) {
+fn assert_collaborators(collaborators: &HashMap<PeerId, Collaborator>, ids: &[Option<UserId>]) {
+    let mut user_ids = collaborators
+        .values()
+        .map(|collaborator| collaborator.user_id)
+        .collect::<Vec<_>>();
+    user_ids.sort();
     assert_eq!(
-        collaborators
-            .into_iter()
-            .map(|collaborator| collaborator.user_id)
-            .collect::<Vec<_>>(),
+        user_ids,
         ids.into_iter().map(|id| id.unwrap()).collect::<Vec<_>>()
     );
 }

crates/collab/src/tests/channel_message_tests.rs

@@ -1,7 +1,9 @@
 use crate::{rpc::RECONNECT_TIMEOUT, tests::TestServer};
 use channel::{ChannelChat, ChannelMessageId};
-use gpui::{executor::Deterministic, ModelHandle, TestAppContext};
+use collab_ui::chat_panel::ChatPanel;
+use gpui::{executor::Deterministic, BorrowAppContext, ModelHandle, TestAppContext};
 use std::sync::Arc;
+use workspace::dock::Panel;
 
 #[gpui::test]
 async fn test_basic_channel_messages(
@@ -223,3 +225,136 @@ fn assert_messages(chat: &ModelHandle<ChannelChat>, messages: &[&str], cx: &mut
         messages
     );
 }
+
+#[gpui::test]
+async fn test_channel_message_changes(
+    deterministic: Arc<Deterministic>,
+    cx_a: &mut TestAppContext,
+    cx_b: &mut TestAppContext,
+) {
+    deterministic.forbid_parking();
+    let mut server = TestServer::start(&deterministic).await;
+    let client_a = server.create_client(cx_a, "user_a").await;
+    let client_b = server.create_client(cx_b, "user_b").await;
+
+    let channel_id = server
+        .make_channel(
+            "the-channel",
+            None,
+            (&client_a, cx_a),
+            &mut [(&client_b, cx_b)],
+        )
+        .await;
+
+    // Client A sends a message, client B should see that there is a new message.
+    let channel_chat_a = client_a
+        .channel_store()
+        .update(cx_a, |store, cx| store.open_channel_chat(channel_id, cx))
+        .await
+        .unwrap();
+
+    channel_chat_a
+        .update(cx_a, |c, cx| c.send_message("one".into(), cx).unwrap())
+        .await
+        .unwrap();
+
+    deterministic.run_until_parked();
+
+    let b_has_messages = cx_b.read_with(|cx| {
+        client_b
+            .channel_store()
+            .read(cx)
+            .has_new_messages(channel_id)
+            .unwrap()
+    });
+
+    assert!(b_has_messages);
+
+    // Opening the chat should clear the changed flag.
+    cx_b.update(|cx| {
+        collab_ui::init(&client_b.app_state, cx);
+    });
+    let project_b = client_b.build_empty_local_project(cx_b);
+    let workspace_b = client_b.build_workspace(&project_b, cx_b).root(cx_b);
+    let chat_panel_b = workspace_b.update(cx_b, |workspace, cx| ChatPanel::new(workspace, cx));
+    chat_panel_b
+        .update(cx_b, |chat_panel, cx| {
+            chat_panel.set_active(true, cx);
+            chat_panel.select_channel(channel_id, cx)
+        })
+        .await
+        .unwrap();
+
+    deterministic.run_until_parked();
+
+    let b_has_messages = cx_b.read_with(|cx| {
+        client_b
+            .channel_store()
+            .read(cx)
+            .has_new_messages(channel_id)
+            .unwrap()
+    });
+
+    assert!(!b_has_messages);
+
+    // Sending a message while the chat is open should not change the flag.
+    channel_chat_a
+        .update(cx_a, |c, cx| c.send_message("two".into(), cx).unwrap())
+        .await
+        .unwrap();
+
+    deterministic.run_until_parked();
+
+    let b_has_messages = cx_b.read_with(|cx| {
+        client_b
+            .channel_store()
+            .read(cx)
+            .has_new_messages(channel_id)
+            .unwrap()
+    });
+
+    assert!(!b_has_messages);
+
+    // Sending a message while the chat is closed should change the flag.
+    chat_panel_b.update(cx_b, |chat_panel, cx| {
+        chat_panel.set_active(false, cx);
+    });
+
+    // Sending a message while the chat is open should not change the flag.
+    channel_chat_a
+        .update(cx_a, |c, cx| c.send_message("three".into(), cx).unwrap())
+        .await
+        .unwrap();
+
+    deterministic.run_until_parked();
+
+    let b_has_messages = cx_b.read_with(|cx| {
+        client_b
+            .channel_store()
+            .read(cx)
+            .has_new_messages(channel_id)
+            .unwrap()
+    });
+
+    assert!(b_has_messages);
+
+    // Closing the chat should re-enable change tracking
+    cx_b.update(|_| drop(chat_panel_b));
+
+    channel_chat_a
+        .update(cx_a, |c, cx| c.send_message("four".into(), cx).unwrap())
+        .await
+        .unwrap();
+
+    deterministic.run_until_parked();
+
+    let b_has_messages = cx_b.read_with(|cx| {
+        client_b
+            .channel_store()
+            .read(cx)
+            .has_new_messages(channel_id)
+            .unwrap()
+    });
+
+    assert!(b_has_messages);
+}

crates/collab/src/tests/random_channel_buffer_tests.rs

@@ -273,7 +273,7 @@ impl RandomizedTest for RandomChannelBufferTest {
                         // channel buffer.
                         let collaborators = channel_buffer.collaborators();
                         let mut user_ids =
-                            collaborators.iter().map(|c| c.user_id).collect::<Vec<_>>();
+                            collaborators.values().map(|c| c.user_id).collect::<Vec<_>>();
                         user_ids.sort();
                         assert_eq!(
                             user_ids,

crates/collab/src/tests/test_server.rs

@@ -1,7 +1,7 @@
 use crate::{
     db::{tests::TestDb, NewUserParams, UserId},
     executor::Executor,
-    rpc::{Server, CLEANUP_TIMEOUT},
+    rpc::{Server, CLEANUP_TIMEOUT, RECONNECT_TIMEOUT},
     AppState,
 };
 use anyhow::anyhow;
@@ -17,6 +17,7 @@ use gpui::{executor::Deterministic, ModelHandle, Task, TestAppContext, WindowHan
 use language::LanguageRegistry;
 use parking_lot::Mutex;
 use project::{Project, WorktreeId};
+use rpc::RECEIVE_TIMEOUT;
 use settings::SettingsStore;
 use std::{
     cell::{Ref, RefCell, RefMut},
@@ -29,7 +30,7 @@ use std::{
     },
 };
 use util::http::FakeHttpClient;
-use workspace::Workspace;
+use workspace::{Workspace, WorkspaceStore};
 
 pub struct TestServer {
     pub app_state: Arc<AppState>,
@@ -151,12 +152,12 @@ impl TestServer {
 
         Arc::get_mut(&mut client)
             .unwrap()
-            .set_id(user_id.0 as usize)
+            .set_id(user_id.to_proto())
             .override_authenticate(move |cx| {
                 cx.spawn(|_| async move {
                     let access_token = "the-token".to_string();
                     Ok(Credentials {
-                        user_id: user_id.0 as u64,
+                        user_id: user_id.to_proto(),
                         access_token,
                     })
                 })
@@ -204,13 +205,17 @@ impl TestServer {
 
         let fs = FakeFs::new(cx.background());
         let user_store = cx.add_model(|cx| UserStore::new(client.clone(), http, cx));
+        let workspace_store = cx.add_model(|cx| WorkspaceStore::new(client.clone(), cx));
         let channel_store =
             cx.add_model(|cx| ChannelStore::new(client.clone(), user_store.clone(), cx));
+        let mut language_registry = LanguageRegistry::test();
+        language_registry.set_executor(cx.background());
         let app_state = Arc::new(workspace::AppState {
             client: client.clone(),
             user_store: user_store.clone(),
+            workspace_store,
             channel_store: channel_store.clone(),
-            languages: Arc::new(LanguageRegistry::test()),
+            languages: Arc::new(language_registry),
             fs: fs.clone(),
             build_window_options: |_, _, _| Default::default(),
             initialize_workspace: |_, _, _, _| Task::ready(Ok(())),
@@ -251,6 +256,19 @@ impl TestServer {
             .store(true, SeqCst);
     }
 
+    pub fn simulate_long_connection_interruption(
+        &self,
+        peer_id: PeerId,
+        deterministic: &Arc<Deterministic>,
+    ) {
+        self.forbid_connections();
+        self.disconnect_client(peer_id);
+        deterministic.advance_clock(RECEIVE_TIMEOUT + RECONNECT_TIMEOUT);
+        self.allow_connections();
+        deterministic.advance_clock(RECEIVE_TIMEOUT + RECONNECT_TIMEOUT);
+        deterministic.run_until_parked();
+    }
+
     pub fn forbid_connections(&self) {
         self.forbid_connections.store(true, SeqCst);
     }
@@ -536,15 +554,7 @@ impl TestClient {
         root_path: impl AsRef<Path>,
         cx: &mut TestAppContext,
     ) -> (ModelHandle<Project>, WorktreeId) {
-        let project = cx.update(|cx| {
-            Project::local(
-                self.client().clone(),
-                self.app_state.user_store.clone(),
-                self.app_state.languages.clone(),
-                self.app_state.fs.clone(),
-                cx,
-            )
-        });
+        let project = self.build_empty_local_project(cx);
         let (worktree, _) = project
             .update(cx, |p, cx| {
                 p.find_or_create_local_worktree(root_path, true, cx)
@@ -557,6 +567,18 @@ impl TestClient {
         (project, worktree.read_with(cx, |tree, _| tree.id()))
     }
 
+    pub fn build_empty_local_project(&self, cx: &mut TestAppContext) -> ModelHandle<Project> {
+        cx.update(|cx| {
+            Project::local(
+                self.client().clone(),
+                self.app_state.user_store.clone(),
+                self.app_state.languages.clone(),
+                self.app_state.fs.clone(),
+                cx,
+            )
+        })
+    }
+
     pub async fn build_remote_project(
         &self,
         host_project_id: u64,

crates/collab_ui/Cargo.toml

@@ -37,6 +37,7 @@ fuzzy = { path = "../fuzzy" }
 gpui = { path = "../gpui" }
 language = { path = "../language" }
 menu = { path = "../menu" }
+rich_text = { path = "../rich_text" }
 picker = { path = "../picker" }
 project = { path = "../project" }
 recent_projects = {path = "../recent_projects"}

crates/collab_ui/src/channel_view.rs

@@ -1,10 +1,12 @@
 use anyhow::{anyhow, Result};
-use call::ActiveCall;
-use channel::{ChannelBuffer, ChannelBufferEvent, ChannelId};
-use client::proto;
-use clock::ReplicaId;
+use call::report_call_event_for_channel;
+use channel::{Channel, ChannelBuffer, ChannelBufferEvent, ChannelId, ChannelStore};
+use client::{
+    proto::{self, PeerId},
+    Collaborator, ParticipantIndex,
+};
 use collections::HashMap;
-use editor::Editor;
+use editor::{CollaborationHub, Editor};
 use gpui::{
     actions,
     elements::{ChildView, Label},
@@ -13,7 +15,11 @@ use gpui::{
     ViewContext, ViewHandle,
 };
 use project::Project;
-use std::any::{Any, TypeId};
+use std::{
+    any::{Any, TypeId},
+    sync::Arc,
+};
+use util::ResultExt;
 use workspace::{
     item::{FollowableItem, Item, ItemHandle},
     register_followable_item,
@@ -23,44 +29,43 @@ use workspace::{
 
 actions!(channel_view, [Deploy]);
 
-pub(crate) fn init(cx: &mut AppContext) {
+pub fn init(cx: &mut AppContext) {
     register_followable_item::<ChannelView>(cx)
 }
 
 pub struct ChannelView {
     pub editor: ViewHandle<Editor>,
     project: ModelHandle<Project>,
+    channel_store: ModelHandle<ChannelStore>,
     channel_buffer: ModelHandle<ChannelBuffer>,
     remote_id: Option<ViewId>,
     _editor_event_subscription: Subscription,
 }
 
 impl ChannelView {
-    pub fn deploy(channel_id: ChannelId, workspace: ViewHandle<Workspace>, cx: &mut AppContext) {
+    pub fn open(
+        channel_id: ChannelId,
+        workspace: ViewHandle<Workspace>,
+        cx: &mut AppContext,
+    ) -> Task<Result<ViewHandle<Self>>> {
         let pane = workspace.read(cx).active_pane().clone();
-        let channel_view = Self::open(channel_id, pane.clone(), workspace.clone(), cx);
+        let channel_view = Self::open_in_pane(channel_id, pane.clone(), workspace.clone(), cx);
         cx.spawn(|mut cx| async move {
             let channel_view = channel_view.await?;
             pane.update(&mut cx, |pane, cx| {
-                let room_id = ActiveCall::global(cx)
-                    .read(cx)
-                    .room()
-                    .map(|room| room.read(cx).id());
-                ActiveCall::report_call_event_for_room(
+                report_call_event_for_channel(
                     "open channel notes",
-                    room_id,
-                    Some(channel_id),
+                    channel_id,
                     &workspace.read(cx).app_state().client,
                     cx,
                 );
-                pane.add_item(Box::new(channel_view), true, true, None, cx);
+                pane.add_item(Box::new(channel_view.clone()), true, true, None, cx);
             });
-            anyhow::Ok(())
+            anyhow::Ok(channel_view)
         })
-        .detach();
     }
 
-    pub fn open(
+    pub fn open_in_pane(
         channel_id: ChannelId,
         pane: ViewHandle<Pane>,
         workspace: ViewHandle<Workspace>,
@@ -79,17 +84,24 @@ impl ChannelView {
         cx.spawn(|mut cx| async move {
             let channel_buffer = channel_buffer.await?;
 
-            let markdown = markdown.await?;
-            channel_buffer.update(&mut cx, |buffer, cx| {
-                buffer.buffer().update(cx, |buffer, cx| {
-                    buffer.set_language(Some(markdown), cx);
-                })
-            });
+            if let Some(markdown) = markdown.await.log_err() {
+                channel_buffer.update(&mut cx, |buffer, cx| {
+                    buffer.buffer().update(cx, |buffer, cx| {
+                        buffer.set_language(Some(markdown), cx);
+                    })
+                });
+            }
 
             pane.update(&mut cx, |pane, cx| {
                 pane.items_of_type::<Self>()
                     .find(|channel_view| channel_view.read(cx).channel_buffer == channel_buffer)
-                    .unwrap_or_else(|| cx.add_view(|cx| Self::new(project, channel_buffer, cx)))
+                    .unwrap_or_else(|| {
+                        cx.add_view(|cx| {
+                            let mut this = Self::new(project, channel_store, channel_buffer, cx);
+                            this.acknowledge_buffer_version(cx);
+                            this
+                        })
+                    })
             })
             .ok_or_else(|| anyhow!("pane was dropped"))
         })
@@ -97,44 +109,35 @@ impl ChannelView {
 
     pub fn new(
         project: ModelHandle<Project>,
+        channel_store: ModelHandle<ChannelStore>,
         channel_buffer: ModelHandle<ChannelBuffer>,
         cx: &mut ViewContext<Self>,
     ) -> Self {
         let buffer = channel_buffer.read(cx).buffer();
-        let editor = cx.add_view(|cx| Editor::for_buffer(buffer, None, cx));
+        let editor = cx.add_view(|cx| {
+            let mut editor = Editor::for_buffer(buffer, None, cx);
+            editor.set_collaboration_hub(Box::new(ChannelBufferCollaborationHub(
+                channel_buffer.clone(),
+            )));
+            editor
+        });
         let _editor_event_subscription = cx.subscribe(&editor, |_, _, e, cx| cx.emit(e.clone()));
 
-        cx.subscribe(&project, Self::handle_project_event).detach();
         cx.subscribe(&channel_buffer, Self::handle_channel_buffer_event)
             .detach();
 
-        let this = Self {
+        Self {
             editor,
             project,
+            channel_store,
             channel_buffer,
             remote_id: None,
             _editor_event_subscription,
-        };
-        this.refresh_replica_id_map(cx);
-        this
+        }
     }
 
-    fn handle_project_event(
-        &mut self,
-        _: ModelHandle<Project>,
-        event: &project::Event,
-        cx: &mut ViewContext<Self>,
-    ) {
-        match event {
-            project::Event::RemoteIdChanged(_) => {}
-            project::Event::DisconnectedFromHost => {}
-            project::Event::Closed => {}
-            project::Event::CollaboratorUpdated { .. } => {}
-            project::Event::CollaboratorLeft(_) => {}
-            project::Event::CollaboratorJoined(_) => {}
-            _ => return,
-        }
-        self.refresh_replica_id_map(cx);
+    pub fn channel(&self, cx: &AppContext) -> Arc<Channel> {
+        self.channel_buffer.read(cx).channel()
     }
 
     fn handle_channel_buffer_event(
@@ -144,48 +147,41 @@ impl ChannelView {
         cx: &mut ViewContext<Self>,
     ) {
         match event {
-            ChannelBufferEvent::CollaboratorsChanged => {
-                self.refresh_replica_id_map(cx);
-            }
             ChannelBufferEvent::Disconnected => self.editor.update(cx, |editor, cx| {
                 editor.set_read_only(true);
                 cx.notify();
             }),
+            ChannelBufferEvent::BufferEdited => {
+                if cx.is_self_focused() || self.editor.is_focused(cx) {
+                    self.acknowledge_buffer_version(cx);
+                } else {
+                    self.channel_store.update(cx, |store, cx| {
+                        let channel_buffer = self.channel_buffer.read(cx);
+                        store.notes_changed(
+                            channel_buffer.channel().id,
+                            channel_buffer.epoch(),
+                            &channel_buffer.buffer().read(cx).version(),
+                            cx,
+                        )
+                    });
+                }
+            }
+            _ => {}
         }
     }
 
-    /// Build a mapping of channel buffer replica ids to the corresponding
-    /// replica ids in the current project.
-    ///
-    /// Using this mapping, a given user can be displayed with the same color
-    /// in the channel buffer as in other files in the project. Users who are
-    /// in the channel buffer but not the project will not have a color.
-    fn refresh_replica_id_map(&self, cx: &mut ViewContext<Self>) {
-        let mut project_replica_ids_by_channel_buffer_replica_id = HashMap::default();
-        let project = self.project.read(cx);
-        let channel_buffer = self.channel_buffer.read(cx);
-        project_replica_ids_by_channel_buffer_replica_id
-            .insert(channel_buffer.replica_id(cx), project.replica_id());
-        project_replica_ids_by_channel_buffer_replica_id.extend(
-            channel_buffer
-                .collaborators()
-                .iter()
-                .filter_map(|channel_buffer_collaborator| {
-                    project
-                        .collaborators()
-                        .values()
-                        .find_map(|project_collaborator| {
-                            (project_collaborator.user_id == channel_buffer_collaborator.user_id)
-                                .then_some((
-                                    channel_buffer_collaborator.replica_id as ReplicaId,
-                                    project_collaborator.replica_id,
-                                ))
-                        })
-                }),
-        );
-
-        self.editor.update(cx, |editor, cx| {
-            editor.set_replica_id_map(Some(project_replica_ids_by_channel_buffer_replica_id), cx)
+    fn acknowledge_buffer_version(&mut self, cx: &mut ViewContext<'_, '_, ChannelView>) {
+        self.channel_store.update(cx, |store, cx| {
+            let channel_buffer = self.channel_buffer.read(cx);
+            store.acknowledge_notes_version(
+                channel_buffer.channel().id,
+                channel_buffer.epoch(),
+                &channel_buffer.buffer().read(cx).version(),
+                cx,
+            )
+        });
+        self.channel_buffer.update(cx, |buffer, cx| {
+            buffer.acknowledge_buffer_version(cx);
         });
     }
 }
@@ -205,6 +201,7 @@ impl View for ChannelView {
 
     fn focus_in(&mut self, _: AnyViewHandle, cx: &mut ViewContext<Self>) {
         if cx.is_self_focused() {
+            self.acknowledge_buffer_version(cx);
             cx.focus(self.editor.as_any())
         }
     }
@@ -244,6 +241,7 @@ impl Item for ChannelView {
     fn clone_on_split(&self, _: WorkspaceId, cx: &mut ViewContext<Self>) -> Option<Self> {
         Some(Self::new(
             self.project.clone(),
+            self.channel_store.clone(),
             self.channel_buffer.clone(),
             cx,
         ))
@@ -316,7 +314,7 @@ impl FollowableItem for ChannelView {
             unreachable!()
         };
 
-        let open = ChannelView::open(state.channel_id, pane, workspace, cx);
+        let open = ChannelView::open_in_pane(state.channel_id, pane, workspace, cx);
 
         Some(cx.spawn(|mut cx| async move {
             let this = open.await?;
@@ -376,17 +374,32 @@ impl FollowableItem for ChannelView {
         })
     }
 
-    fn set_leader_replica_id(
-        &mut self,
-        leader_replica_id: Option<u16>,
-        cx: &mut ViewContext<Self>,
-    ) {
+    fn set_leader_peer_id(&mut self, leader_peer_id: Option<PeerId>, cx: &mut ViewContext<Self>) {
         self.editor.update(cx, |editor, cx| {
-            editor.set_leader_replica_id(leader_replica_id, cx)
+            editor.set_leader_peer_id(leader_peer_id, cx)
         })
     }
 
     fn should_unfollow_on_event(event: &Self::Event, cx: &AppContext) -> bool {
         Editor::should_unfollow_on_event(event, cx)
     }
+
+    fn is_project_item(&self, _cx: &AppContext) -> bool {
+        false
+    }
+}
+
+struct ChannelBufferCollaborationHub(ModelHandle<ChannelBuffer>);
+
+impl CollaborationHub for ChannelBufferCollaborationHub {
+    fn collaborators<'a>(&self, cx: &'a AppContext) -> &'a HashMap<PeerId, Collaborator> {
+        self.0.read(cx).collaborators()
+    }
+
+    fn user_participant_indices<'a>(
+        &self,
+        cx: &'a AppContext,
+    ) -> &'a HashMap<u64, ParticipantIndex> {
+        self.0.read(cx).user_store().read(cx).participant_indices()
+    }
 }

crates/collab_ui/src/chat_panel.rs

@@ -3,6 +3,7 @@ use anyhow::Result;
 use call::ActiveCall;
 use channel::{ChannelChat, ChannelChatEvent, ChannelMessageId, ChannelStore};
 use client::Client;
+use collections::HashMap;
 use db::kvp::KEY_VALUE_STORE;
 use editor::Editor;
 use feature_flags::{ChannelsAlpha, FeatureFlagAppExt};
@@ -12,12 +13,13 @@ use gpui::{
     platform::{CursorStyle, MouseButton},
     serde_json,
     views::{ItemType, Select, SelectStyle},
-    AnyViewHandle, AppContext, AsyncAppContext, Entity, ModelHandle, Subscription, Task, View,
-    ViewContext, ViewHandle, WeakViewHandle,
+    AnyViewHandle, AppContext, AsyncAppContext, Entity, ImageData, ModelHandle, Subscription, Task,
+    View, ViewContext, ViewHandle, WeakViewHandle,
 };
-use language::language_settings::SoftWrap;
+use language::{language_settings::SoftWrap, LanguageRegistry};
 use menu::Confirm;
 use project::Fs;
+use rich_text::RichText;
 use serde::{Deserialize, Serialize};
 use settings::SettingsStore;
 use std::sync::Arc;
@@ -35,6 +37,7 @@ const CHAT_PANEL_KEY: &'static str = "ChatPanel";
 pub struct ChatPanel {
     client: Arc<Client>,
     channel_store: ModelHandle<ChannelStore>,
+    languages: Arc<LanguageRegistry>,
     active_chat: Option<(ModelHandle<ChannelChat>, Subscription)>,
     message_list: ListState<ChatPanel>,
     input_editor: ViewHandle<Editor>,
@@ -42,10 +45,12 @@ pub struct ChatPanel {
     local_timezone: UtcOffset,
     fs: Arc<dyn Fs>,
     width: Option<f32>,
+    active: bool,
     pending_serialization: Task<Option<()>>,
     subscriptions: Vec<gpui::Subscription>,
     workspace: WeakViewHandle<Workspace>,
     has_focus: bool,
+    markdown_data: HashMap<ChannelMessageId, RichText>,
 }
 
 #[derive(Serialize, Deserialize)]
@@ -77,6 +82,7 @@ impl ChatPanel {
         let fs = workspace.app_state().fs.clone();
         let client = workspace.app_state().client.clone();
         let channel_store = workspace.app_state().channel_store.clone();
+        let languages = workspace.app_state().languages.clone();
 
         let input_editor = cx.add_view(|cx| {
             let mut editor = Editor::auto_height(
@@ -129,6 +135,8 @@ impl ChatPanel {
                 fs,
                 client,
                 channel_store,
+                languages,
+
                 active_chat: Default::default(),
                 pending_serialization: Task::ready(None),
                 message_list,
@@ -138,7 +146,9 @@ impl ChatPanel {
                 has_focus: false,
                 subscriptions: Vec::new(),
                 workspace: workspace_handle,
+                active: false,
                 width: None,
+                markdown_data: Default::default(),
             };
 
             let mut old_dock_position = this.position(cx);
@@ -154,9 +164,9 @@ impl ChatPanel {
                     }),
                 );
 
-            this.init_active_channel(cx);
+            this.update_channel_count(cx);
             cx.observe(&this.channel_store, |this, _, cx| {
-                this.init_active_channel(cx);
+                this.update_channel_count(cx)
             })
             .detach();
 
@@ -175,10 +185,33 @@ impl ChatPanel {
             })
             .detach();
 
+            let markdown = this.languages.language_for_name("Markdown");
+            cx.spawn(|this, mut cx| async move {
+                let markdown = markdown.await?;
+
+                this.update(&mut cx, |this, cx| {
+                    this.input_editor.update(cx, |editor, cx| {
+                        editor.buffer().update(cx, |multi_buffer, cx| {
+                            multi_buffer
+                                .as_singleton()
+                                .unwrap()
+                                .update(cx, |buffer, cx| buffer.set_language(Some(markdown), cx))
+                        })
+                    })
+                })?;
+
+                anyhow::Ok(())
+            })
+            .detach_and_log_err(cx);
+
             this
         })
     }
 
+    pub fn active_chat(&self) -> Option<ModelHandle<ChannelChat>> {
+        self.active_chat.as_ref().map(|(chat, _)| chat.clone())
+    }
+
     pub fn load(
         workspace: WeakViewHandle<Workspace>,
         cx: AsyncAppContext,
@@ -225,10 +258,8 @@ impl ChatPanel {
         );
     }
 
-    fn init_active_channel(&mut self, cx: &mut ViewContext<Self>) {
+    fn update_channel_count(&mut self, cx: &mut ViewContext<Self>) {
         let channel_count = self.channel_store.read(cx).channel_count();
-        self.message_list.reset(0);
-        self.active_chat = None;
         self.channel_select.update(cx, |select, cx| {
             select.set_item_count(channel_count, cx);
         });
@@ -247,6 +278,7 @@ impl ChatPanel {
             }
             let subscription = cx.subscribe(&chat, Self::channel_did_change);
             self.active_chat = Some((chat, subscription));
+            self.acknowledge_last_message(cx);
             self.channel_select.update(cx, |select, cx| {
                 if let Some(ix) = self.channel_store.read(cx).index_of_channel(id) {
                     select.set_selected_index(ix, cx);
@@ -268,11 +300,34 @@ impl ChatPanel {
                 new_count,
             } => {
                 self.message_list.splice(old_range.clone(), *new_count);
+                if self.active {
+                    self.acknowledge_last_message(cx);
+                }
+            }
+            ChannelChatEvent::NewMessage {
+                channel_id,
+                message_id,
+            } => {
+                if !self.active {
+                    self.channel_store.update(cx, |store, cx| {
+                        store.new_message(*channel_id, *message_id, cx)
+                    })
+                }
             }
         }
         cx.notify();
     }
 
+    fn acknowledge_last_message(&mut self, cx: &mut ViewContext<'_, '_, ChatPanel>) {
+        if self.active {
+            if let Some((chat, _)) = &self.active_chat {
+                chat.update(cx, |chat, cx| {
+                    chat.acknowledge_last_message(cx);
+                });
+            }
+        }
+    }
+
     fn render_channel(&self, cx: &mut ViewContext<Self>) -> AnyElement<Self> {
         let theme = theme::current(cx);
         Flex::column()
@@ -299,13 +354,33 @@ impl ChatPanel {
         messages.flex(1., true).into_any()
     }
 
-    fn render_message(&self, ix: usize, cx: &mut ViewContext<Self>) -> AnyElement<Self> {
-        let message = self.active_chat.as_ref().unwrap().0.read(cx).message(ix);
+    fn render_message(&mut self, ix: usize, cx: &mut ViewContext<Self>) -> AnyElement<Self> {
+        let (message, is_continuation, is_last) = {
+            let active_chat = self.active_chat.as_ref().unwrap().0.read(cx);
+            let last_message = active_chat.message(ix.saturating_sub(1));
+            let this_message = active_chat.message(ix);
+            let is_continuation = last_message.id != this_message.id
+                && this_message.sender.id == last_message.sender.id;
+
+            (
+                active_chat.message(ix).clone(),
+                is_continuation,
+                active_chat.message_count() == ix + 1,
+            )
+        };
+
+        let is_pending = message.is_pending();
+        let text = self
+            .markdown_data
+            .entry(message.id)
+            .or_insert_with(|| rich_text::render_markdown(message.body, &self.languages, None));
 
         let now = OffsetDateTime::now_utc();
         let theme = theme::current(cx);
-        let style = if message.is_pending() {
+        let style = if is_pending {
             &theme.chat_panel.pending_message
+        } else if is_continuation {
+            &theme.chat_panel.continuation_message
         } else {
             &theme.chat_panel.message
         };
@@ -318,52 +393,90 @@ impl ChatPanel {
                 None
             };
 
-        enum DeleteMessage {}
-
-        let body = message.body.clone();
-        Flex::column()
-            .with_child(
+        enum MessageBackgroundHighlight {}
+        MouseEventHandler::new::<MessageBackgroundHighlight, _>(ix, cx, |state, cx| {
+            let container = style.container.style_for(state);
+            if is_continuation {
                 Flex::row()
                     .with_child(
-                        Label::new(
-                            message.sender.github_login.clone(),
-                            style.sender.text.clone(),
+                        text.element(
+                            theme.editor.syntax.clone(),
+                            style.body.clone(),
+                            theme.editor.document_highlight_read_background,
+                            cx,
                         )
-                        .contained()
-                        .with_style(style.sender.container),
+                        .flex(1., true),
+                    )
+                    .with_child(render_remove(message_id_to_remove, cx, &theme))
+                    .contained()
+                    .with_style(*container)
+                    .with_margin_bottom(if is_last {
+                        theme.chat_panel.last_message_bottom_spacing
+                    } else {
+                        0.
+                    })
+                    .into_any()
+            } else {
+                Flex::column()
+                    .with_child(
+                        Flex::row()
+                            .with_child(
+                                Flex::row()
+                                    .with_child(render_avatar(
+                                        message.sender.avatar.clone(),
+                                        &theme,
+                                    ))
+                                    .with_child(
+                                        Label::new(
+                                            message.sender.github_login.clone(),
+                                            style.sender.text.clone(),
+                                        )
+                                        .contained()
+                                        .with_style(style.sender.container),
+                                    )
+                                    .with_child(
+                                        Label::new(
+                                            format_timestamp(
+                                                message.timestamp,
+                                                now,
+                                                self.local_timezone,
+                                            ),
+                                            style.timestamp.text.clone(),
+                                        )
+                                        .contained()
+                                        .with_style(style.timestamp.container),
+                                    )
+                                    .align_children_center()
+                                    .flex(1., true),
+                            )
+                            .with_child(render_remove(message_id_to_remove, cx, &theme))
+                            .align_children_center(),
                     )
                     .with_child(
-                        Label::new(
-                            format_timestamp(message.timestamp, now, self.local_timezone),
-                            style.timestamp.text.clone(),
-                        )
-                        .contained()
-                        .with_style(style.timestamp.container),
+                        Flex::row()
+                            .with_child(
+                                text.element(
+                                    theme.editor.syntax.clone(),
+                                    style.body.clone(),
+                                    theme.editor.document_highlight_read_background,
+                                    cx,
+                                )
+                                .flex(1., true),
+                            )
+                            // Add a spacer to make everything line up
+                            .with_child(render_remove(None, cx, &theme)),
                     )
-                    .with_children(message_id_to_remove.map(|id| {
-                        MouseEventHandler::new::<DeleteMessage, _>(
-                            id as usize,
-                            cx,
-                            |mouse_state, _| {
-                                let button_style =
-                                    theme.chat_panel.icon_button.style_for(mouse_state);
-                                render_icon_button(button_style, "icons/x.svg")
-                                    .aligned()
-                                    .into_any()
-                            },
-                        )
-                        .with_padding(Padding::uniform(2.))
-                        .with_cursor_style(CursorStyle::PointingHand)
-                        .on_click(MouseButton::Left, move |_, this, cx| {
-                            this.remove_message(id, cx);
-                        })
-                        .flex_float()
-                    })),
-            )
-            .with_child(Text::new(body, style.body.clone()))
-            .contained()
-            .with_style(style.container)
-            .into_any()
+                    .contained()
+                    .with_style(*container)
+                    .with_margin_bottom(if is_last {
+                        theme.chat_panel.last_message_bottom_spacing
+                    } else {
+                        0.
+                    })
+                    .into_any()
+            }
+        })
+        .into_any()
     }
 
     fn render_input_box(&self, theme: &Arc<Theme>, cx: &AppContext) -> AnyElement<Self> {
@@ -409,7 +522,7 @@ impl ChatPanel {
                 })
                 .on_click(MouseButton::Left, move |_, _, cx| {
                     if let Some(workspace) = workspace.upgrade(cx) {
-                        ChannelView::deploy(channel_id, workspace, cx);
+                        ChannelView::open(channel_id, workspace, cx).detach();
                     }
                 })
                 .with_tooltip::<OpenChannelNotes>(
@@ -537,6 +650,7 @@ impl ChatPanel {
         cx.spawn(|this, mut cx| async move {
             let chat = open_chat.await?;
             this.update(&mut cx, |this, cx| {
+                this.markdown_data = Default::default();
                 this.set_active_chat(chat, cx);
             })
         })
@@ -546,7 +660,7 @@ impl ChatPanel {
         if let Some((chat, _)) = &self.active_chat {
             let channel_id = chat.read(cx).channel().id;
             if let Some(workspace) = self.workspace.upgrade(cx) {
-                ChannelView::deploy(channel_id, workspace, cx);
+                ChannelView::open(channel_id, workspace, cx).detach();
             }
         }
     }
@@ -561,6 +675,72 @@ impl ChatPanel {
     }
 }
 
+fn render_avatar(avatar: Option<Arc<ImageData>>, theme: &Arc<Theme>) -> AnyElement<ChatPanel> {
+    let avatar_style = theme.chat_panel.avatar;
+
+    avatar
+        .map(|avatar| {
+            Image::from_data(avatar)
+                .with_style(avatar_style.image)
+                .aligned()
+                .contained()
+                .with_corner_radius(avatar_style.outer_corner_radius)
+                .constrained()
+                .with_width(avatar_style.outer_width)
+                .with_height(avatar_style.outer_width)
+                .into_any()
+        })
+        .unwrap_or_else(|| {
+            Empty::new()
+                .constrained()
+                .with_width(avatar_style.outer_width)
+                .into_any()
+        })
+        .contained()
+        .with_style(theme.chat_panel.avatar_container)
+        .into_any()
+}
+
+fn render_remove(
+    message_id_to_remove: Option<u64>,
+    cx: &mut ViewContext<'_, '_, ChatPanel>,
+    theme: &Arc<Theme>,
+) -> AnyElement<ChatPanel> {
+    enum DeleteMessage {}
+
+    message_id_to_remove
+        .map(|id| {
+            MouseEventHandler::new::<DeleteMessage, _>(id as usize, cx, |mouse_state, _| {
+                let button_style = theme.chat_panel.icon_button.style_for(mouse_state);
+                render_icon_button(button_style, "icons/x.svg")
+                    .aligned()
+                    .into_any()
+            })
+            .with_padding(Padding::uniform(2.))
+            .with_cursor_style(CursorStyle::PointingHand)
+            .on_click(MouseButton::Left, move |_, this, cx| {
+                this.remove_message(id, cx);
+            })
+            .flex_float()
+            .into_any()
+        })
+        .unwrap_or_else(|| {
+            let style = theme.chat_panel.icon_button.default;
+
+            Empty::new()
+                .constrained()
+                .with_width(style.icon_width)
+                .aligned()
+                .constrained()
+                .with_width(style.button_width)
+                .with_height(style.button_width)
+                .contained()
+                .with_uniform_padding(2.)
+                .flex_float()
+                .into_any()
+        })
+}
+
 impl Entity for ChatPanel {
     type Event = Event;
 }
@@ -627,8 +807,12 @@ impl Panel for ChatPanel {
     }
 
     fn set_active(&mut self, active: bool, cx: &mut ViewContext<Self>) {
-        if active && !is_chat_feature_enabled(cx) {
-            cx.emit(Event::Dismissed);
+        self.active = active;
+        if active {
+            self.acknowledge_last_message(cx);
+            if !is_chat_feature_enabled(cx) {
+                cx.emit(Event::Dismissed);
+            }
         }
     }
 

crates/collab_ui/src/collab_titlebar_item.rs

@@ -215,7 +215,13 @@ impl CollabTitlebarItem {
         let git_style = theme.titlebar.git_menu_button.clone();
         let item_spacing = theme.titlebar.item_spacing;
 
-        let mut ret = Flex::row().with_child(
+        let mut ret = Flex::row();
+
+        if let Some(project_host) = self.collect_project_host(theme.clone(), cx) {
+            ret = ret.with_child(project_host)
+        }
+
+        ret = ret.with_child(
             Stack::new()
                 .with_child(
                     MouseEventHandler::new::<ToggleProjectMenu, _>(0, cx, |mouse_state, cx| {
@@ -283,6 +289,71 @@ impl CollabTitlebarItem {
         ret.into_any()
     }
 
+    fn collect_project_host(
+        &self,
+        theme: Arc<Theme>,
+        cx: &mut ViewContext<Self>,
+    ) -> Option<AnyElement<Self>> {
+        if ActiveCall::global(cx).read(cx).room().is_none() {
+            return None;
+        }
+        let project = self.project.read(cx);
+        let user_store = self.user_store.read(cx);
+
+        if project.is_local() {
+            return None;
+        }
+
+        let Some(host) = project.host() else {
+            return None;
+        };
+        let (Some(host_user), Some(participant_index)) = (
+            user_store.get_cached_user(host.user_id),
+            user_store.participant_indices().get(&host.user_id),
+        ) else {
+            return None;
+        };
+
+        enum ProjectHost {}
+        enum ProjectHostTooltip {}
+
+        let host_style = theme.titlebar.project_host.clone();
+        let selection_style = theme
+            .editor
+            .selection_style_for_room_participant(participant_index.0);
+        let peer_id = host.peer_id.clone();
+
+        Some(
+            MouseEventHandler::new::<ProjectHost, _>(0, cx, |mouse_state, _| {
+                let mut host_style = host_style.style_for(mouse_state).clone();
+                host_style.text.color = selection_style.cursor;
+                Label::new(host_user.github_login.clone(), host_style.text)
+                    .contained()
+                    .with_style(host_style.container)
+                    .aligned()
+                    .left()
+            })
+            .with_cursor_style(CursorStyle::PointingHand)
+            .on_click(MouseButton::Left, move |_, this, cx| {
+                if let Some(workspace) = this.workspace.upgrade(cx) {
+                    if let Some(task) =
+                        workspace.update(cx, |workspace, cx| workspace.follow(peer_id, cx))
+                    {
+                        task.detach_and_log_err(cx);
+                    }
+                }
+            })
+            .with_tooltip::<ProjectHostTooltip>(
+                0,
+                host_user.github_login.clone() + " is sharing this project. Click to follow.",
+                None,
+                theme.tooltip.clone(),
+                cx,
+            )
+            .into_any_named("project-host"),
+        )
+    }
+
     fn window_activation_changed(&mut self, active: bool, cx: &mut ViewContext<Self>) {
         let project = if active {
             Some(self.project.clone())
@@ -877,7 +948,7 @@ impl CollabTitlebarItem {
     fn render_face_pile(
         &self,
         user: &User,
-        replica_id: Option<ReplicaId>,
+        _replica_id: Option<ReplicaId>,
         peer_id: PeerId,
         location: Option<ParticipantLocation>,
         muted: bool,
@@ -886,23 +957,20 @@ impl CollabTitlebarItem {
         theme: &Theme,
         cx: &mut ViewContext<Self>,
     ) -> AnyElement<Self> {
+        let user_id = user.id;
         let project_id = workspace.read(cx).project().read(cx).remote_id();
-        let room = ActiveCall::global(cx).read(cx).room();
-        let is_being_followed = workspace.read(cx).is_being_followed(peer_id);
-        let followed_by_self = room
-            .and_then(|room| {
-                Some(
-                    is_being_followed
-                        && room
-                            .read(cx)
-                            .followers_for(peer_id, project_id?)
-                            .iter()
-                            .any(|&follower| {
-                                Some(follower) == workspace.read(cx).client().peer_id()
-                            }),
-                )
-            })
-            .unwrap_or(false);
+        let room = ActiveCall::global(cx).read(cx).room().cloned();
+        let self_peer_id = workspace.read(cx).client().peer_id();
+        let self_following = workspace.read(cx).is_being_followed(peer_id);
+        let self_following_initialized = self_following
+            && room.as_ref().map_or(false, |room| match project_id {
+                None => true,
+                Some(project_id) => room
+                    .read(cx)
+                    .followers_for(peer_id, project_id)
+                    .iter()
+                    .any(|&follower| Some(follower) == self_peer_id),
+            });
 
         let leader_style = theme.titlebar.leader_avatar;
         let follower_style = theme.titlebar.follower_avatar;
@@ -921,147 +989,131 @@ impl CollabTitlebarItem {
             .background_color
             .unwrap_or_default();
 
-        if let Some(replica_id) = replica_id {
-            if followed_by_self {
-                let selection = theme.editor.replica_selection_style(replica_id).selection;
+        let participant_index = self
+            .user_store
+            .read(cx)
+            .participant_indices()
+            .get(&user_id)
+            .copied();
+        if let Some(participant_index) = participant_index {
+            if self_following_initialized {
+                let selection = theme
+                    .editor
+                    .selection_style_for_room_participant(participant_index.0)
+                    .selection;
                 background_color = Color::blend(selection, background_color);
                 background_color.a = 255;
             }
         }
 
-        let mut content = Stack::new()
-            .with_children(user.avatar.as_ref().map(|avatar| {
-                let face_pile = FacePile::new(theme.titlebar.follower_avatar_overlap)
-                    .with_child(Self::render_face(
-                        avatar.clone(),
-                        Self::location_style(workspace, location, leader_style, cx),
-                        background_color,
-                        microphone_state,
-                    ))
-                    .with_children(
-                        (|| {
-                            let project_id = project_id?;
-                            let room = room?.read(cx);
-                            let followers = room.followers_for(peer_id, project_id);
+        enum TitlebarParticipant {}
 
-                            Some(followers.into_iter().flat_map(|&follower| {
-                                let remote_participant =
-                                    room.remote_participant_for_peer_id(follower);
-
-                                let avatar = remote_participant
-                                    .and_then(|p| p.user.avatar.clone())
-                                    .or_else(|| {
-                                        if follower == workspace.read(cx).client().peer_id()? {
-                                            workspace
-                                                .read(cx)
-                                                .user_store()
-                                                .read(cx)
-                                                .current_user()?
-                                                .avatar
-                                                .clone()
-                                        } else {
-                                            None
+        let content = MouseEventHandler::new::<TitlebarParticipant, _>(
+            peer_id.as_u64() as usize,
+            cx,
+            move |_, cx| {
+                Stack::new()
+                    .with_children(user.avatar.as_ref().map(|avatar| {
+                        let face_pile = FacePile::new(theme.titlebar.follower_avatar_overlap)
+                            .with_child(Self::render_face(
+                                avatar.clone(),
+                                Self::location_style(workspace, location, leader_style, cx),
+                                background_color,
+                                microphone_state,
+                            ))
+                            .with_children(
+                                (|| {
+                                    let project_id = project_id?;
+                                    let room = room?.read(cx);
+                                    let followers = room.followers_for(peer_id, project_id);
+                                    Some(followers.into_iter().filter_map(|&follower| {
+                                        if Some(follower) == self_peer_id {
+                                            return None;
                                         }
-                                    })?;
+                                        let participant =
+                                            room.remote_participant_for_peer_id(follower)?;
+                                        Some(Self::render_face(
+                                            participant.user.avatar.clone()?,
+                                            follower_style,
+                                            background_color,
+                                            None,
+                                        ))
+                                    }))
+                                })()
+                                .into_iter()
+                                .flatten(),
+                            )
+                            .with_children(
+                                self_following_initialized
+                                    .then(|| self.user_store.read(cx).current_user())
+                                    .and_then(|user| {
+                                        Some(Self::render_face(
+                                            user?.avatar.clone()?,
+                                            follower_style,
+                                            background_color,
+                                            None,
+                                        ))
+                                    }),
+                            );
 
-                                Some(Self::render_face(
-                                    avatar.clone(),
-                                    follower_style,
-                                    background_color,
-                                    None,
-                                ))
-                            }))
-                        })()
-                        .into_iter()
-                        .flatten(),
-                    );
+                        let mut container = face_pile
+                            .contained()
+                            .with_style(theme.titlebar.leader_selection);
 
-                let mut container = face_pile
-                    .contained()
-                    .with_style(theme.titlebar.leader_selection);
-
-                if let Some(replica_id) = replica_id {
-                    if followed_by_self {
-                        let color = theme.editor.replica_selection_style(replica_id).selection;
-                        container = container.with_background_color(color);
-                    }
-                }
-
-                container
-            }))
-            .with_children((|| {
-                let replica_id = replica_id?;
-                let color = theme.editor.replica_selection_style(replica_id).cursor;
-                Some(
-                    AvatarRibbon::new(color)
-                        .constrained()
-                        .with_width(theme.titlebar.avatar_ribbon.width)
-                        .with_height(theme.titlebar.avatar_ribbon.height)
-                        .aligned()
-                        .bottom(),
-                )
-            })())
-            .into_any();
-
-        if let Some(location) = location {
-            if let Some(replica_id) = replica_id {
-                enum ToggleFollow {}
-
-                content = MouseEventHandler::new::<ToggleFollow, _>(
-                    replica_id.into(),
-                    cx,
-                    move |_, _| content,
-                )
-                .with_cursor_style(CursorStyle::PointingHand)
-                .on_click(MouseButton::Left, move |_, item, cx| {
-                    if let Some(workspace) = item.workspace.upgrade(cx) {
-                        if let Some(task) = workspace
-                            .update(cx, |workspace, cx| workspace.toggle_follow(peer_id, cx))
-                        {
-                            task.detach_and_log_err(cx);
+                        if let Some(participant_index) = participant_index {
+                            if self_following_initialized {
+                                let color = theme
+                                    .editor
+                                    .selection_style_for_room_participant(participant_index.0)
+                                    .selection;
+                                container = container.with_background_color(color);
+                            }
                         }
-                    }
-                })
-                .with_tooltip::<ToggleFollow>(
-                    peer_id.as_u64() as usize,
-                    if is_being_followed {
-                        format!("Unfollow {}", user.github_login)
-                    } else {
-                        format!("Follow {}", user.github_login)
-                    },
-                    Some(Box::new(FollowNextCollaborator)),
-                    theme.tooltip.clone(),
-                    cx,
-                )
-                .into_any();
-            } else if let ParticipantLocation::SharedProject { project_id } = location {
-                enum JoinProject {}
 
-                let user_id = user.id;
-                content = MouseEventHandler::new::<JoinProject, _>(
-                    peer_id.as_u64() as usize,
-                    cx,
-                    move |_, _| content,
-                )
-                .with_cursor_style(CursorStyle::PointingHand)
-                .on_click(MouseButton::Left, move |_, this, cx| {
-                    if let Some(workspace) = this.workspace.upgrade(cx) {
-                        let app_state = workspace.read(cx).app_state().clone();
-                        workspace::join_remote_project(project_id, user_id, app_state, cx)
-                            .detach_and_log_err(cx);
-                    }
-                })
-                .with_tooltip::<JoinProject>(
-                    peer_id.as_u64() as usize,
-                    format!("Follow {} into external project", user.github_login),
-                    Some(Box::new(FollowNextCollaborator)),
-                    theme.tooltip.clone(),
-                    cx,
-                )
-                .into_any();
-            }
+                        container
+                    }))
+                    .with_children((|| {
+                        let participant_index = participant_index?;
+                        let color = theme
+                            .editor
+                            .selection_style_for_room_participant(participant_index.0)
+                            .cursor;
+                        Some(
+                            AvatarRibbon::new(color)
+                                .constrained()
+                                .with_width(theme.titlebar.avatar_ribbon.width)
+                                .with_height(theme.titlebar.avatar_ribbon.height)
+                                .aligned()
+                                .bottom(),
+                        )
+                    })())
+            },
+        );
+
+        if Some(peer_id) == self_peer_id {
+            return content.into_any();
         }
+
         content
+            .with_cursor_style(CursorStyle::PointingHand)
+            .on_click(MouseButton::Left, move |_, this, cx| {
+                let Some(workspace) = this.workspace.upgrade(cx) else {
+                    return;
+                };
+                if let Some(task) =
+                    workspace.update(cx, |workspace, cx| workspace.follow(peer_id, cx))
+                {
+                    task.detach_and_log_err(cx);
+                }
+            })
+            .with_tooltip::<TitlebarParticipant>(
+                peer_id.as_u64() as usize,
+                format!("Follow {}", user.github_login),
+                Some(Box::new(FollowNextCollaborator)),
+                theme.tooltip.clone(),
+                cx,
+            )
+            .into_any()
     }
 
     fn location_style(

crates/collab_ui/src/collab_ui.rs

@@ -7,10 +7,10 @@ mod face_pile;
 mod incoming_call_notification;
 mod notifications;
 mod panel_settings;
-mod project_shared_notification;
+pub mod project_shared_notification;
 mod sharing_status_indicator;
 
-use call::{ActiveCall, Room};
+use call::{report_call_event_for_room, ActiveCall, Room};
 use gpui::{
     actions,
     geometry::{
@@ -55,18 +55,18 @@ pub fn toggle_screen_sharing(_: &ToggleScreenSharing, cx: &mut AppContext) {
         let client = call.client();
         let toggle_screen_sharing = room.update(cx, |room, cx| {
             if room.is_screen_sharing() {
-                ActiveCall::report_call_event_for_room(
+                report_call_event_for_room(
                     "disable screen share",
-                    Some(room.id()),
+                    room.id(),
                     room.channel_id(),
                     &client,
                     cx,
                 );
                 Task::ready(room.unshare_screen(cx))
             } else {
-                ActiveCall::report_call_event_for_room(
+                report_call_event_for_room(
                     "enable screen share",
-                    Some(room.id()),
+                    room.id(),
                     room.channel_id(),
                     &client,
                     cx,
@@ -83,23 +83,13 @@ pub fn toggle_mute(_: &ToggleMute, cx: &mut AppContext) {
     if let Some(room) = call.room().cloned() {
         let client = call.client();
         room.update(cx, |room, cx| {
-            if room.is_muted(cx) {
-                ActiveCall::report_call_event_for_room(
-                    "enable microphone",
-                    Some(room.id()),
-                    room.channel_id(),
-                    &client,
-                    cx,
-                );
+            let operation = if room.is_muted(cx) {
+                "enable microphone"
             } else {
-                ActiveCall::report_call_event_for_room(
-                    "disable microphone",
-                    Some(room.id()),
-                    room.channel_id(),
-                    &client,
-                    cx,
-                );
-            }
+                "disable microphone"
+            };
+            report_call_event_for_room(operation, room.id(), room.channel_id(), &client, cx);
+
             room.toggle_mute(cx)
         })
         .map(|task| task.detach_and_log_err(cx))

crates/collab_ui/src/project_shared_notification.rs

@@ -40,7 +40,9 @@ pub fn init(app_state: &Arc<AppState>, cx: &mut AppContext) {
                     .push(window);
             }
         }
-        room::Event::RemoteProjectUnshared { project_id } => {
+        room::Event::RemoteProjectUnshared { project_id }
+        | room::Event::RemoteProjectJoined { project_id }
+        | room::Event::RemoteProjectInvitationDiscarded { project_id } => {
             if let Some(windows) = notification_windows.remove(&project_id) {
                 for window in windows {
                     window.remove(cx);
@@ -82,7 +84,6 @@ impl ProjectSharedNotification {
     }
 
     fn join(&mut self, cx: &mut ViewContext<Self>) {
-        cx.remove_window();
         if let Some(app_state) = self.app_state.upgrade() {
             workspace::join_remote_project(self.project_id, self.owner.id, app_state, cx)
                 .detach_and_log_err(cx);
@@ -90,7 +91,15 @@ impl ProjectSharedNotification {
     }
 
     fn dismiss(&mut self, cx: &mut ViewContext<Self>) {
-        cx.remove_window();
+        if let Some(active_room) =
+            ActiveCall::global(cx).read_with(cx, |call, _| call.room().cloned())
+        {
+            active_room.update(cx, |_, cx| {
+                cx.emit(room::Event::RemoteProjectInvitationDiscarded {
+                    project_id: self.project_id,
+                });
+            });
+        }
     }
 
     fn render_owner(&self, cx: &mut ViewContext<Self>) -> AnyElement<Self> {

crates/command_palette/src/command_palette.rs

@@ -18,6 +18,15 @@ actions!(command_palette, [Toggle]);
 
 pub type CommandPalette = Picker<CommandPaletteDelegate>;
 
+pub type CommandPaletteInterceptor =
+    Box<dyn Fn(&str, &AppContext) -> Option<CommandInterceptResult>>;
+
+pub struct CommandInterceptResult {
+    pub action: Box<dyn Action>,
+    pub string: String,
+    pub positions: Vec<usize>,
+}
+
 pub struct CommandPaletteDelegate {
     actions: Vec<Command>,
     matches: Vec<StringMatch>,
@@ -117,7 +126,7 @@ impl PickerDelegate for CommandPaletteDelegate {
                     }
                 })
                 .collect::<Vec<_>>();
-            let actions = cx.read(move |cx| {
+            let mut actions = cx.read(move |cx| {
                 let hit_counts = cx.optional_global::<HitCounts>();
                 actions.sort_by_key(|action| {
                     (
@@ -136,7 +145,7 @@ impl PickerDelegate for CommandPaletteDelegate {
                     char_bag: command.name.chars().collect(),
                 })
                 .collect::<Vec<_>>();
-            let matches = if query.is_empty() {
+            let mut matches = if query.is_empty() {
                 candidates
                     .into_iter()
                     .enumerate()
@@ -158,6 +167,40 @@ impl PickerDelegate for CommandPaletteDelegate {
                 )
                 .await
             };
+            let intercept_result = cx.read(|cx| {
+                if cx.has_global::<CommandPaletteInterceptor>() {
+                    cx.global::<CommandPaletteInterceptor>()(&query, cx)
+                } else {
+                    None
+                }
+            });
+            if let Some(CommandInterceptResult {
+                action,
+                string,
+                positions,
+            }) = intercept_result
+            {
+                if let Some(idx) = matches
+                    .iter()
+                    .position(|m| actions[m.candidate_id].action.id() == action.id())
+                {
+                    matches.remove(idx);
+                }
+                actions.push(Command {
+                    name: string.clone(),
+                    action,
+                    keystrokes: vec![],
+                });
+                matches.insert(
+                    0,
+                    StringMatch {
+                        candidate_id: actions.len() - 1,
+                        string,
+                        positions,
+                        score: 0.0,
+                    },
+                )
+            }
             picker
                 .update(&mut cx, |picker, _| {
                     let delegate = picker.delegate_mut();
@@ -222,7 +265,7 @@ impl PickerDelegate for CommandPaletteDelegate {
                     .with_children(
                         [
                             (keystroke.ctrl, "^"),
-                            (keystroke.alt, "⎇"),
+                            (keystroke.alt, "⌥"),
                             (keystroke.cmd, "⌘"),
                             (keystroke.shift, "⇧"),
                         ]

crates/diagnostics/Cargo.toml

@@ -21,6 +21,9 @@ util = { path = "../util" }
 workspace = { path = "../workspace" }
 
 anyhow.workspace = true
+schemars.workspace = true
+serde.workspace = true
+serde_derive.workspace = true
 smallvec.workspace = true
 postage.workspace = true
 

crates/diagnostics/src/diagnostics.rs

@@ -1,4 +1,6 @@
 pub mod items;
+mod project_diagnostics_settings;
+mod toolbar_controls;
 
 use anyhow::Result;
 use collections::{BTreeSet, HashSet};
@@ -19,6 +21,7 @@ use language::{
 };
 use lsp::LanguageServerId;
 use project::{DiagnosticSummary, Project, ProjectPath};
+use project_diagnostics_settings::ProjectDiagnosticsSettings;
 use serde_json::json;
 use smallvec::SmallVec;
 use std::{
@@ -30,18 +33,21 @@ use std::{
     sync::Arc,
 };
 use theme::ThemeSettings;
+pub use toolbar_controls::ToolbarControls;
 use util::TryFutureExt;
 use workspace::{
     item::{BreadcrumbText, Item, ItemEvent, ItemHandle},
     ItemNavHistory, Pane, PaneBackdrop, ToolbarItemLocation, Workspace,
 };
 
-actions!(diagnostics, [Deploy]);
+actions!(diagnostics, [Deploy, ToggleWarnings]);
 
 const CONTEXT_LINE_COUNT: u32 = 1;
 
 pub fn init(cx: &mut AppContext) {
+    settings::register::<ProjectDiagnosticsSettings>(cx);
     cx.add_action(ProjectDiagnosticsEditor::deploy);
+    cx.add_action(ProjectDiagnosticsEditor::toggle_warnings);
     items::init(cx);
 }
 
@@ -55,6 +61,7 @@ struct ProjectDiagnosticsEditor {
     excerpts: ModelHandle<MultiBuffer>,
     path_states: Vec<PathState>,
     paths_to_update: BTreeSet<(ProjectPath, LanguageServerId)>,
+    include_warnings: bool,
 }
 
 struct PathState {
@@ -187,6 +194,7 @@ impl ProjectDiagnosticsEditor {
             editor,
             path_states: Default::default(),
             paths_to_update,
+            include_warnings: settings::get::<ProjectDiagnosticsSettings>(cx).include_warnings,
         };
         this.update_excerpts(None, cx);
         this
@@ -204,6 +212,18 @@ impl ProjectDiagnosticsEditor {
         }
     }
 
+    fn toggle_warnings(&mut self, _: &ToggleWarnings, cx: &mut ViewContext<Self>) {
+        self.include_warnings = !self.include_warnings;
+        self.paths_to_update = self
+            .project
+            .read(cx)
+            .diagnostic_summaries(cx)
+            .map(|(path, server_id, _)| (path, server_id))
+            .collect();
+        self.update_excerpts(None, cx);
+        cx.notify();
+    }
+
     fn update_excerpts(
         &mut self,
         language_server_id: Option<LanguageServerId>,
@@ -277,14 +297,18 @@ impl ProjectDiagnosticsEditor {
         let mut blocks_to_add = Vec::new();
         let mut blocks_to_remove = HashSet::default();
         let mut first_excerpt_id = None;
+        let max_severity = if self.include_warnings {
+            DiagnosticSeverity::WARNING
+        } else {
+            DiagnosticSeverity::ERROR
+        };
         let excerpts_snapshot = self.excerpts.update(cx, |excerpts, excerpts_cx| {
             let mut old_groups = path_state.diagnostic_groups.iter().enumerate().peekable();
             let mut new_groups = snapshot
                 .diagnostic_groups(language_server_id)
                 .into_iter()
                 .filter(|(_, group)| {
-                    group.entries[group.primary_ix].diagnostic.severity
-                        <= DiagnosticSeverity::WARNING
+                    group.entries[group.primary_ix].diagnostic.severity <= max_severity
                 })
                 .peekable();
             loop {
@@ -1501,6 +1525,7 @@ mod tests {
             client::init_settings(cx);
             workspace::init_settings(cx);
             Project::init_settings(cx);
+            crate::init(cx);
         });
     }
 

crates/diagnostics/src/project_diagnostics_settings.rs

@@ -0,0 +1,28 @@
+use schemars::JsonSchema;
+use serde::{Deserialize, Serialize};
+
+#[derive(Deserialize, Debug)]
+pub struct ProjectDiagnosticsSettings {
+    pub include_warnings: bool,
+}
+
+#[derive(Clone, Default, Serialize, Deserialize, JsonSchema, Debug)]
+pub struct ProjectDiagnosticsSettingsContent {
+    include_warnings: Option<bool>,
+}
+
+impl settings::Setting for ProjectDiagnosticsSettings {
+    const KEY: Option<&'static str> = Some("diagnostics");
+    type FileContent = ProjectDiagnosticsSettingsContent;
+
+    fn load(
+        default_value: &Self::FileContent,
+        user_values: &[&Self::FileContent],
+        _cx: &gpui::AppContext,
+    ) -> anyhow::Result<Self>
+    where
+        Self: Sized,
+    {
+        Self::load_via_json_merge(default_value, user_values)
+    }
+}

crates/diagnostics/src/toolbar_controls.rs

@@ -0,0 +1,115 @@
+use crate::{ProjectDiagnosticsEditor, ToggleWarnings};
+use gpui::{
+    elements::*,
+    platform::{CursorStyle, MouseButton},
+    Action, Entity, EventContext, View, ViewContext, WeakViewHandle,
+};
+use workspace::{item::ItemHandle, ToolbarItemLocation, ToolbarItemView};
+
+pub struct ToolbarControls {
+    editor: Option<WeakViewHandle<ProjectDiagnosticsEditor>>,
+}
+
+impl Entity for ToolbarControls {
+    type Event = ();
+}
+
+impl View for ToolbarControls {
+    fn ui_name() -> &'static str {
+        "ToolbarControls"
+    }
+
+    fn render(&mut self, cx: &mut ViewContext<Self>) -> AnyElement<Self> {
+        let include_warnings = self
+            .editor
+            .as_ref()
+            .and_then(|editor| editor.upgrade(cx))
+            .map(|editor| editor.read(cx).include_warnings)
+            .unwrap_or(false);
+        let tooltip = if include_warnings {
+            "Exclude Warnings".into()
+        } else {
+            "Include Warnings".into()
+        };
+        Flex::row()
+            .with_child(render_toggle_button(
+                0,
+                "icons/warning.svg",
+                include_warnings,
+                (tooltip, Some(Box::new(ToggleWarnings))),
+                cx,
+                move |this, cx| {
+                    if let Some(editor) = this.editor.and_then(|editor| editor.upgrade(cx)) {
+                        editor.update(cx, |editor, cx| {
+                            editor.toggle_warnings(&Default::default(), cx)
+                        });
+                    }
+                },
+            ))
+            .into_any()
+    }
+}
+
+impl ToolbarItemView for ToolbarControls {
+    fn set_active_pane_item(
+        &mut self,
+        active_pane_item: Option<&dyn ItemHandle>,
+        _: &mut ViewContext<Self>,
+    ) -> ToolbarItemLocation {
+        if let Some(pane_item) = active_pane_item.as_ref() {
+            if let Some(editor) = pane_item.downcast::<ProjectDiagnosticsEditor>() {
+                self.editor = Some(editor.downgrade());
+                ToolbarItemLocation::PrimaryRight { flex: None }
+            } else {
+                ToolbarItemLocation::Hidden
+            }
+        } else {
+            ToolbarItemLocation::Hidden
+        }
+    }
+}
+
+impl ToolbarControls {
+    pub fn new() -> Self {
+        ToolbarControls { editor: None }
+    }
+}
+
+fn render_toggle_button<
+    F: 'static + Fn(&mut ToolbarControls, &mut EventContext<ToolbarControls>),
+>(
+    index: usize,
+    icon: &'static str,
+    toggled: bool,
+    tooltip: (String, Option<Box<dyn Action>>),
+    cx: &mut ViewContext<ToolbarControls>,
+    on_click: F,
+) -> AnyElement<ToolbarControls> {
+    enum Button {}
+
+    let theme = theme::current(cx);
+    let (tooltip_text, action) = tooltip;
+
+    MouseEventHandler::new::<Button, _>(index, cx, |mouse_state, _| {
+        let style = theme
+            .workspace
+            .toolbar
+            .toggleable_tool
+            .in_state(toggled)
+            .style_for(mouse_state);
+        Svg::new(icon)
+            .with_color(style.color)
+            .constrained()
+            .with_width(style.icon_width)
+            .aligned()
+            .constrained()
+            .with_width(style.button_width)
+            .with_height(style.button_width)
+            .contained()
+            .with_style(style.container)
+    })
+    .with_cursor_style(CursorStyle::PointingHand)
+    .on_click(MouseButton::Left, move |_, view, cx| on_click(view, cx))
+    .with_tooltip::<Button>(index, tooltip_text, action, theme.tooltip.clone(), cx)
+    .into_any_named("quick action bar button")
+}

crates/editor/Cargo.toml

@@ -36,6 +36,7 @@ language = { path = "../language" }
 lsp = { path = "../lsp" }
 project = { path = "../project" }
 rpc = { path = "../rpc" }
+rich_text = { path = "../rich_text" }
 settings = { path = "../settings" }
 snippet = { path = "../snippet" }
 sum_tree = { path = "../sum_tree" }

crates/editor/src/editor.rs

@@ -25,7 +25,7 @@ use ::git::diff::DiffHunk;
 use aho_corasick::AhoCorasick;
 use anyhow::{anyhow, Context, Result};
 use blink_manager::BlinkManager;
-use client::{ClickhouseEvent, TelemetrySettings};
+use client::{ClickhouseEvent, Collaborator, ParticipantIndex, TelemetrySettings};
 use clock::{Global, ReplicaId};
 use collections::{BTreeMap, Bound, HashMap, HashSet, VecDeque};
 use convert_case::{Case, Casing};
@@ -79,6 +79,7 @@ pub use multi_buffer::{
 use ordered_float::OrderedFloat;
 use project::{FormatTrigger, Location, Project, ProjectPath, ProjectTransaction};
 use rand::{seq::SliceRandom, thread_rng};
+use rpc::proto::PeerId;
 use scroll::{
     autoscroll::Autoscroll, OngoingScroll, ScrollAnchor, ScrollManager, ScrollbarAutoHide,
 };
@@ -103,7 +104,7 @@ use sum_tree::TreeMap;
 use text::Rope;
 use theme::{DiagnosticStyle, Theme, ThemeSettings};
 use util::{post_inc, RangeExt, ResultExt, TryFutureExt};
-use workspace::{ItemNavHistory, ViewId, Workspace};
+use workspace::{ItemNavHistory, SplitDirection, ViewId, Workspace};
 
 use crate::git::diff_hunk_to_display;
 
@@ -363,6 +364,7 @@ pub fn init_settings(cx: &mut AppContext) {
 pub fn init(cx: &mut AppContext) {
     init_settings(cx);
     cx.add_action(Editor::new_file);
+    cx.add_action(Editor::new_file_in_direction);
     cx.add_action(Editor::cancel);
     cx.add_action(Editor::newline);
     cx.add_action(Editor::newline_above);
@@ -580,11 +582,11 @@ pub struct Editor {
     get_field_editor_theme: Option<Arc<GetFieldEditorTheme>>,
     override_text_style: Option<Box<OverrideTextStyle>>,
     project: Option<ModelHandle<Project>>,
+    collaboration_hub: Option<Box<dyn CollaborationHub>>,
     focused: bool,
     blink_manager: ModelHandle<BlinkManager>,
     pub show_local_selections: bool,
     mode: EditorMode,
-    replica_id_mapping: Option<HashMap<ReplicaId, ReplicaId>>,
     show_gutter: bool,
     show_wrap_guides: Option<bool>,
     placeholder_text: Option<Arc<str>>,
@@ -608,7 +610,7 @@ pub struct Editor {
     keymap_context_layers: BTreeMap<TypeId, KeymapContext>,
     input_enabled: bool,
     read_only: bool,
-    leader_replica_id: Option<u16>,
+    leader_peer_id: Option<PeerId>,
     remote_id: Option<ViewId>,
     hover_state: HoverState,
     gutter_hovered: bool,
@@ -630,6 +632,15 @@ pub struct EditorSnapshot {
     ongoing_scroll: OngoingScroll,
 }
 
+pub struct RemoteSelection {
+    pub replica_id: ReplicaId,
+    pub selection: Selection<Anchor>,
+    pub cursor_shape: CursorShape,
+    pub peer_id: PeerId,
+    pub line_mode: bool,
+    pub participant_index: Option<ParticipantIndex>,
+}
+
 #[derive(Clone, Debug)]
 struct SelectionHistoryEntry {
     selections: Arc<[Selection<Anchor>]>,
@@ -1046,7 +1057,8 @@ impl CompletionsMenu {
                                     item_ix: Some(item_ix),
                                 },
                                 cx,
-                            );
+                            )
+                            .map(|task| task.detach());
                         })
                         .into_any(),
                     );
@@ -1538,12 +1550,12 @@ impl Editor {
             active_diagnostics: None,
             soft_wrap_mode_override,
             get_field_editor_theme,
+            collaboration_hub: project.clone().map(|project| Box::new(project) as _),
             project,
             focused: false,
             blink_manager: blink_manager.clone(),
             show_local_selections: true,
             mode,
-            replica_id_mapping: None,
             show_gutter: mode == EditorMode::Full,
             show_wrap_guides: None,
             placeholder_text: None,
@@ -1570,7 +1582,7 @@ impl Editor {
             keymap_context_layers: Default::default(),
             input_enabled: true,
             read_only: false,
-            leader_replica_id: None,
+            leader_peer_id: None,
             remote_id: None,
             hover_state: Default::default(),
             link_go_to_definition_state: Default::default(),
@@ -1633,12 +1645,32 @@ impl Editor {
         }
     }
 
+    pub fn new_file_in_direction(
+        workspace: &mut Workspace,
+        action: &workspace::NewFileInDirection,
+        cx: &mut ViewContext<Workspace>,
+    ) {
+        let project = workspace.project().clone();
+        if project.read(cx).is_remote() {
+            cx.propagate_action();
+        } else if let Some(buffer) = project
+            .update(cx, |project, cx| project.create_buffer("", None, cx))
+            .log_err()
+        {
+            workspace.split_item(
+                action.0,
+                Box::new(cx.add_view(|cx| Editor::for_buffer(buffer, Some(project.clone()), cx))),
+                cx,
+            );
+        }
+    }
+
     pub fn replica_id(&self, cx: &AppContext) -> ReplicaId {
         self.buffer.read(cx).replica_id()
     }
 
-    pub fn leader_replica_id(&self) -> Option<ReplicaId> {
-        self.leader_replica_id
+    pub fn leader_peer_id(&self) -> Option<PeerId> {
+        self.leader_peer_id
     }
 
     pub fn buffer(&self) -> &ModelHandle<MultiBuffer> {
@@ -1702,6 +1734,14 @@ impl Editor {
         self.mode
     }
 
+    pub fn collaboration_hub(&self) -> Option<&dyn CollaborationHub> {
+        self.collaboration_hub.as_deref()
+    }
+
+    pub fn set_collaboration_hub(&mut self, hub: Box<dyn CollaborationHub>) {
+        self.collaboration_hub = Some(hub);
+    }
+
     pub fn set_placeholder_text(
         &mut self,
         placeholder_text: impl Into<Arc<str>>,
@@ -1778,26 +1818,13 @@ impl Editor {
         cx.notify();
     }
 
-    pub fn replica_id_map(&self) -> Option<&HashMap<ReplicaId, ReplicaId>> {
-        self.replica_id_mapping.as_ref()
-    }
-
-    pub fn set_replica_id_map(
-        &mut self,
-        mapping: Option<HashMap<ReplicaId, ReplicaId>>,
-        cx: &mut ViewContext<Self>,
-    ) {
-        self.replica_id_mapping = mapping;
-        cx.notify();
-    }
-
     fn selections_did_change(
         &mut self,
         local: bool,
         old_cursor_position: &Anchor,
         cx: &mut ViewContext<Self>,
     ) {
-        if self.focused && self.leader_replica_id.is_none() {
+        if self.focused && self.leader_peer_id.is_none() {
             self.buffer.update(cx, |buffer, cx| {
                 buffer.set_active_selections(
                     &self.selections.disjoint_anchors(),
@@ -4632,7 +4659,13 @@ impl Editor {
     }
 
     pub fn convert_to_title_case(&mut self, _: &ConvertToTitleCase, cx: &mut ViewContext<Self>) {
-        self.manipulate_text(cx, |text| text.to_case(Case::Title))
+        self.manipulate_text(cx, |text| {
+            // Hack to get around the fact that to_case crate doesn't support '\n' as a word boundary
+            // https://github.com/rutrum/convert-case/issues/16
+            text.split("\n")
+                .map(|line| line.to_case(Case::Title))
+                .join("\n")
+        })
     }
 
     pub fn convert_to_snake_case(&mut self, _: &ConvertToSnakeCase, cx: &mut ViewContext<Self>) {
@@ -4648,7 +4681,13 @@ impl Editor {
         _: &ConvertToUpperCamelCase,
         cx: &mut ViewContext<Self>,
     ) {
-        self.manipulate_text(cx, |text| text.to_case(Case::UpperCamel))
+        self.manipulate_text(cx, |text| {
+            // Hack to get around the fact that to_case crate doesn't support '\n' as a word boundary
+            // https://github.com/rutrum/convert-case/issues/16
+            text.split("\n")
+                .map(|line| line.to_case(Case::UpperCamel))
+                .join("\n")
+        })
     }
 
     pub fn convert_to_lower_camel_case(
@@ -7136,7 +7175,7 @@ impl Editor {
             );
         });
         if split {
-            workspace.split_item(Box::new(editor), cx);
+            workspace.split_item(SplitDirection::Right, Box::new(editor), cx);
         } else {
             workspace.add_item(Box::new(editor), cx);
         }
@@ -8567,6 +8606,50 @@ impl Editor {
 
         self.handle_input(text, cx);
     }
+
+    pub fn supports_inlay_hints(&self, cx: &AppContext) -> bool {
+        let Some(project) = self.project.as_ref() else {
+            return false;
+        };
+        let project = project.read(cx);
+
+        let mut supports = false;
+        self.buffer().read(cx).for_each_buffer(|buffer| {
+            if !supports {
+                supports = project
+                    .language_servers_for_buffer(buffer.read(cx), cx)
+                    .any(
+                        |(_, server)| match server.capabilities().inlay_hint_provider {
+                            Some(lsp::OneOf::Left(enabled)) => enabled,
+                            Some(lsp::OneOf::Right(_)) => true,
+                            None => false,
+                        },
+                    )
+            }
+        });
+        supports
+    }
+}
+
+pub trait CollaborationHub {
+    fn collaborators<'a>(&self, cx: &'a AppContext) -> &'a HashMap<PeerId, Collaborator>;
+    fn user_participant_indices<'a>(
+        &self,
+        cx: &'a AppContext,
+    ) -> &'a HashMap<u64, ParticipantIndex>;
+}
+
+impl CollaborationHub for ModelHandle<Project> {
+    fn collaborators<'a>(&self, cx: &'a AppContext) -> &'a HashMap<PeerId, Collaborator> {
+        self.read(cx).collaborators()
+    }
+
+    fn user_participant_indices<'a>(
+        &self,
+        cx: &'a AppContext,
+    ) -> &'a HashMap<u64, ParticipantIndex> {
+        self.read(cx).user_store().read(cx).participant_indices()
+    }
 }
 
 fn inlay_hint_settings(
@@ -8612,6 +8695,34 @@ fn ending_row(next_selection: &Selection<Point>, display_map: &DisplaySnapshot)
 }
 
 impl EditorSnapshot {
+    pub fn remote_selections_in_range<'a>(
+        &'a self,
+        range: &'a Range<Anchor>,
+        collaboration_hub: &dyn CollaborationHub,
+        cx: &'a AppContext,
+    ) -> impl 'a + Iterator<Item = RemoteSelection> {
+        let participant_indices = collaboration_hub.user_participant_indices(cx);
+        let collaborators_by_peer_id = collaboration_hub.collaborators(cx);
+        let collaborators_by_replica_id = collaborators_by_peer_id
+            .iter()
+            .map(|(_, collaborator)| (collaborator.replica_id, collaborator))
+            .collect::<HashMap<_, _>>();
+        self.buffer_snapshot
+            .remote_selections_in_range(range)
+            .filter_map(move |(replica_id, line_mode, cursor_shape, selection)| {
+                let collaborator = collaborators_by_replica_id.get(&replica_id)?;
+                let participant_index = participant_indices.get(&collaborator.user_id).copied();
+                Some(RemoteSelection {
+                    replica_id,
+                    selection,
+                    cursor_shape,
+                    line_mode,
+                    participant_index,
+                    peer_id: collaborator.peer_id,
+                })
+            })
+    }
+
     pub fn language_at<T: ToOffset>(&self, position: T) -> Option<&Arc<Language>> {
         self.display_snapshot.buffer_snapshot.language_at(position)
     }
@@ -8725,7 +8836,7 @@ impl View for Editor {
             self.focused = true;
             self.buffer.update(cx, |buffer, cx| {
                 buffer.finalize_last_transaction(cx);
-                if self.leader_replica_id.is_none() {
+                if self.leader_peer_id.is_none() {
                     buffer.set_active_selections(
                         &self.selections.disjoint_anchors(),
                         self.selections.line_mode,

crates/editor/src/editor_tests.rs

@@ -1429,7 +1429,7 @@ async fn test_scroll_page_up_page_down(cx: &mut gpui::TestAppContext) {
         assert_eq!(editor.snapshot(cx).scroll_position(), vec2f(0., 3.));
 
         editor.scroll_screen(&ScrollAmount::Page(-0.5), cx);
-        assert_eq!(editor.snapshot(cx).scroll_position(), vec2f(0., 2.));
+        assert_eq!(editor.snapshot(cx).scroll_position(), vec2f(0., 1.));
         editor.scroll_screen(&ScrollAmount::Page(0.5), cx);
         assert_eq!(editor.snapshot(cx).scroll_position(), vec2f(0., 3.));
     });
@@ -2792,6 +2792,34 @@ async fn test_manipulate_text(cx: &mut TestAppContext) {
         «hello worldˇ»
     "});
 
+    // Test multiple line, single selection case
+    // Test code hack that covers the fact that to_case crate doesn't support '\n' as a word boundary
+    cx.set_state(indoc! {"
+        «The quick brown
+        fox jumps over
+        the lazy dogˇ»
+    "});
+    cx.update_editor(|e, cx| e.convert_to_title_case(&ConvertToTitleCase, cx));
+    cx.assert_editor_state(indoc! {"
+        «The Quick Brown
+        Fox Jumps Over
+        The Lazy Dogˇ»
+    "});
+
+    // Test multiple line, single selection case
+    // Test code hack that covers the fact that to_case crate doesn't support '\n' as a word boundary
+    cx.set_state(indoc! {"
+        «The quick brown
+        fox jumps over
+        the lazy dogˇ»
+    "});
+    cx.update_editor(|e, cx| e.convert_to_upper_camel_case(&ConvertToUpperCamelCase, cx));
+    cx.assert_editor_state(indoc! {"
+        «TheQuickBrown
+        FoxJumpsOver
+        TheLazyDogˇ»
+    "});
+
     // From here on out, test more complex cases of manipulate_text()
 
     // Test no selection case - should affect words cursors are in

crates/editor/src/element.rs

@@ -17,7 +17,6 @@ use crate::{
     },
     mouse_context_menu, EditorSettings, EditorStyle, GutterHover, UnfoldAt,
 };
-use clock::ReplicaId;
 use collections::{BTreeMap, HashMap};
 use git::diff::DiffHunkStatus;
 use gpui::{
@@ -55,6 +54,7 @@ use std::{
     sync::Arc,
 };
 use text::Point;
+use theme::SelectionStyle;
 use workspace::item::Item;
 
 enum FoldMarkers {}
@@ -868,14 +868,7 @@ impl EditorElement {
         let corner_radius = 0.15 * layout.position_map.line_height;
         let mut invisible_display_ranges = SmallVec::<[Range<DisplayPoint>; 32]>::new();
 
-        for (replica_id, selections) in &layout.selections {
-            let replica_id = *replica_id;
-            let selection_style = if let Some(replica_id) = replica_id {
-                style.replica_selection_style(replica_id)
-            } else {
-                &style.absent_selection
-            };
-
+        for (selection_style, selections) in &layout.selections {
             for selection in selections {
                 self.paint_highlighted_range(
                     selection.range.clone(),
@@ -2193,7 +2186,7 @@ impl Element<Editor> for EditorElement {
                 .anchor_before(DisplayPoint::new(end_row, 0).to_offset(&snapshot, Bias::Right))
         };
 
-        let mut selections: Vec<(Option<ReplicaId>, Vec<SelectionLayout>)> = Vec::new();
+        let mut selections: Vec<(SelectionStyle, Vec<SelectionLayout>)> = Vec::new();
         let mut active_rows = BTreeMap::new();
         let mut fold_ranges = Vec::new();
         let is_singleton = editor.is_singleton(cx);
@@ -2219,35 +2212,6 @@ impl Element<Editor> for EditorElement {
                 }),
         );
 
-        let mut remote_selections = HashMap::default();
-        for (replica_id, line_mode, cursor_shape, selection) in snapshot
-            .buffer_snapshot
-            .remote_selections_in_range(&(start_anchor..end_anchor))
-        {
-            let replica_id = if let Some(mapping) = &editor.replica_id_mapping {
-                mapping.get(&replica_id).copied()
-            } else {
-                Some(replica_id)
-            };
-
-            // The local selections match the leader's selections.
-            if replica_id.is_some() && replica_id == editor.leader_replica_id {
-                continue;
-            }
-            remote_selections
-                .entry(replica_id)
-                .or_insert(Vec::new())
-                .push(SelectionLayout::new(
-                    selection,
-                    line_mode,
-                    cursor_shape,
-                    &snapshot.display_snapshot,
-                    false,
-                    false,
-                ));
-        }
-        selections.extend(remote_selections);
-
         let mut newest_selection_head = None;
 
         if editor.show_local_selections {
@@ -2282,19 +2246,58 @@ impl Element<Editor> for EditorElement {
                 layouts.push(layout);
             }
 
-            // Render the local selections in the leader's color when following.
-            let local_replica_id = if let Some(leader_replica_id) = editor.leader_replica_id {
-                leader_replica_id
-            } else {
-                let replica_id = editor.replica_id(cx);
-                if let Some(mapping) = &editor.replica_id_mapping {
-                    mapping.get(&replica_id).copied().unwrap_or(replica_id)
-                } else {
-                    replica_id
-                }
-            };
+            selections.push((style.selection, layouts));
+        }
 
-            selections.push((Some(local_replica_id), layouts));
+        if let Some(collaboration_hub) = &editor.collaboration_hub {
+            // When following someone, render the local selections in their color.
+            if let Some(leader_id) = editor.leader_peer_id {
+                if let Some(collaborator) = collaboration_hub.collaborators(cx).get(&leader_id) {
+                    if let Some(participant_index) = collaboration_hub
+                        .user_participant_indices(cx)
+                        .get(&collaborator.user_id)
+                    {
+                        if let Some((local_selection_style, _)) = selections.first_mut() {
+                            *local_selection_style =
+                                style.selection_style_for_room_participant(participant_index.0);
+                        }
+                    }
+                }
+            }
+
+            let mut remote_selections = HashMap::default();
+            for selection in snapshot.remote_selections_in_range(
+                &(start_anchor..end_anchor),
+                collaboration_hub.as_ref(),
+                cx,
+            ) {
+                let selection_style = if let Some(participant_index) = selection.participant_index {
+                    style.selection_style_for_room_participant(participant_index.0)
+                } else {
+                    style.absent_selection
+                };
+
+                // Don't re-render the leader's selections, since the local selections
+                // match theirs.
+                if Some(selection.peer_id) == editor.leader_peer_id {
+                    continue;
+                }
+
+                remote_selections
+                    .entry(selection.replica_id)
+                    .or_insert((selection_style, Vec::new()))
+                    .1
+                    .push(SelectionLayout::new(
+                        selection.selection,
+                        selection.line_mode,
+                        selection.cursor_shape,
+                        &snapshot.display_snapshot,
+                        false,
+                        false,
+                    ));
+            }
+
+            selections.extend(remote_selections.into_values());
         }
 
         let scrollbar_settings = &settings::get::<EditorSettings>(cx).scrollbar;
@@ -2686,7 +2689,7 @@ pub struct LayoutState {
     blocks: Vec<BlockLayout>,
     highlighted_ranges: Vec<(Range<DisplayPoint>, Color)>,
     fold_ranges: Vec<(BufferRow, Range<DisplayPoint>, Color)>,
-    selections: Vec<(Option<ReplicaId>, Vec<SelectionLayout>)>,
+    selections: Vec<(SelectionStyle, Vec<SelectionLayout>)>,
     scrollbar_row_range: Range<f32>,
     show_scrollbars: bool,
     is_singleton: bool,

crates/editor/src/hover_popover.rs

@@ -8,12 +8,12 @@ use futures::FutureExt;
 use gpui::{
     actions,
     elements::{Flex, MouseEventHandler, Padding, ParentElement, Text},
-    fonts::{HighlightStyle, Underline, Weight},
     platform::{CursorStyle, MouseButton},
-    AnyElement, AppContext, CursorRegion, Element, ModelHandle, MouseRegion, Task, ViewContext,
+    AnyElement, AppContext, Element, ModelHandle, Task, ViewContext,
 };
 use language::{Bias, DiagnosticEntry, DiagnosticSeverity, Language, LanguageRegistry};
 use project::{HoverBlock, HoverBlockKind, InlayHintLabelPart, Project};
+use rich_text::{new_paragraph, render_code, render_markdown_mut, RichText};
 use std::{ops::Range, sync::Arc, time::Duration};
 use util::TryFutureExt;
 
@@ -346,158 +346,25 @@ fn show_hover(
 }
 
 fn render_blocks(
-    theme_id: usize,
     blocks: &[HoverBlock],
     language_registry: &Arc<LanguageRegistry>,
     language: Option<&Arc<Language>>,
-    style: &EditorStyle,
-) -> RenderedInfo {
-    let mut text = String::new();
-    let mut highlights = Vec::new();
-    let mut region_ranges = Vec::new();
-    let mut regions = Vec::new();
+) -> RichText {
+    let mut data = RichText {
+        text: Default::default(),
+        highlights: Default::default(),
+        region_ranges: Default::default(),
+        regions: Default::default(),
+    };
 
     for block in blocks {
         match &block.kind {
             HoverBlockKind::PlainText => {
-                new_paragraph(&mut text, &mut Vec::new());
-                text.push_str(&block.text);
+                new_paragraph(&mut data.text, &mut Vec::new());
+                data.text.push_str(&block.text);
             }
             HoverBlockKind::Markdown => {
-                use pulldown_cmark::{CodeBlockKind, Event, Options, Parser, Tag};
-
-                let mut bold_depth = 0;
-                let mut italic_depth = 0;
-                let mut link_url = None;
-                let mut current_language = None;
-                let mut list_stack = Vec::new();
-
-                for event in Parser::new_ext(&block.text, Options::all()) {
-                    let prev_len = text.len();
-                    match event {
-                        Event::Text(t) => {
-                            if let Some(language) = &current_language {
-                                render_code(
-                                    &mut text,
-                                    &mut highlights,
-                                    t.as_ref(),
-                                    language,
-                                    style,
-                                );
-                            } else {
-                                text.push_str(t.as_ref());
-
-                                let mut style = HighlightStyle::default();
-                                if bold_depth > 0 {
-                                    style.weight = Some(Weight::BOLD);
-                                }
-                                if italic_depth > 0 {
-                                    style.italic = Some(true);
-                                }
-                                if let Some(link_url) = link_url.clone() {
-                                    region_ranges.push(prev_len..text.len());
-                                    regions.push(RenderedRegion {
-                                        link_url: Some(link_url),
-                                        code: false,
-                                    });
-                                    style.underline = Some(Underline {
-                                        thickness: 1.0.into(),
-                                        ..Default::default()
-                                    });
-                                }
-
-                                if style != HighlightStyle::default() {
-                                    let mut new_highlight = true;
-                                    if let Some((last_range, last_style)) = highlights.last_mut() {
-                                        if last_range.end == prev_len && last_style == &style {
-                                            last_range.end = text.len();
-                                            new_highlight = false;
-                                        }
-                                    }
-                                    if new_highlight {
-                                        highlights.push((prev_len..text.len(), style));
-                                    }
-                                }
-                            }
-                        }
-                        Event::Code(t) => {
-                            text.push_str(t.as_ref());
-                            region_ranges.push(prev_len..text.len());
-                            if link_url.is_some() {
-                                highlights.push((
-                                    prev_len..text.len(),
-                                    HighlightStyle {
-                                        underline: Some(Underline {
-                                            thickness: 1.0.into(),
-                                            ..Default::default()
-                                        }),
-                                        ..Default::default()
-                                    },
-                                ));
-                            }
-                            regions.push(RenderedRegion {
-                                code: true,
-                                link_url: link_url.clone(),
-                            });
-                        }
-                        Event::Start(tag) => match tag {
-                            Tag::Paragraph => new_paragraph(&mut text, &mut list_stack),
-                            Tag::Heading(_, _, _) => {
-                                new_paragraph(&mut text, &mut list_stack);
-                                bold_depth += 1;
-                            }
-                            Tag::CodeBlock(kind) => {
-                                new_paragraph(&mut text, &mut list_stack);
-                                current_language = if let CodeBlockKind::Fenced(language) = kind {
-                                    language_registry
-                                        .language_for_name(language.as_ref())
-                                        .now_or_never()
-                                        .and_then(Result::ok)
-                                } else {
-                                    language.cloned()
-                                }
-                            }
-                            Tag::Emphasis => italic_depth += 1,
-                            Tag::Strong => bold_depth += 1,
-                            Tag::Link(_, url, _) => link_url = Some(url.to_string()),
-                            Tag::List(number) => {
-                                list_stack.push((number, false));
-                            }
-                            Tag::Item => {
-                                let len = list_stack.len();
-                                if let Some((list_number, has_content)) = list_stack.last_mut() {
-                                    *has_content = false;
-                                    if !text.is_empty() && !text.ends_with('\n') {
-                                        text.push('\n');
-                                    }
-                                    for _ in 0..len - 1 {
-                                        text.push_str("  ");
-                                    }
-                                    if let Some(number) = list_number {
-                                        text.push_str(&format!("{}. ", number));
-                                        *number += 1;
-                                        *has_content = false;
-                                    } else {
-                                        text.push_str("- ");
-                                    }
-                                }
-                            }
-                            _ => {}
-                        },
-                        Event::End(tag) => match tag {
-                            Tag::Heading(_, _, _) => bold_depth -= 1,
-                            Tag::CodeBlock(_) => current_language = None,
-                            Tag::Emphasis => italic_depth -= 1,
-                            Tag::Strong => bold_depth -= 1,
-                            Tag::Link(_, _, _) => link_url = None,
-                            Tag::List(_) => drop(list_stack.pop()),
-                            _ => {}
-                        },
-                        Event::HardBreak => text.push('\n'),
-                        Event::SoftBreak => text.push(' '),
-                        _ => {}
-                    }
-                }
+                render_markdown_mut(&block.text, language_registry, language, &mut data)
             }
             HoverBlockKind::Code { language } => {
                 if let Some(language) = language_registry
@@ -505,62 +372,17 @@ fn render_blocks(
                     .now_or_never()
                     .and_then(Result::ok)
                 {
-                    render_code(&mut text, &mut highlights, &block.text, &language, style);
+                    render_code(&mut data.text, &mut data.highlights, &block.text, &language);
                 } else {
-                    text.push_str(&block.text);
+                    data.text.push_str(&block.text);
                 }
             }
         }
     }
 
-    RenderedInfo {
-        theme_id,
-        text: text.trim().to_string(),
-        highlights,
-        region_ranges,
-        regions,
-    }
-}
+    data.text = data.text.trim().to_string();
 
-fn render_code(
-    text: &mut String,
-    highlights: &mut Vec<(Range<usize>, HighlightStyle)>,
-    content: &str,
-    language: &Arc<Language>,
-    style: &EditorStyle,
-) {
-    let prev_len = text.len();
-    text.push_str(content);
-    for (range, highlight_id) in language.highlight_text(&content.into(), 0..content.len()) {
-        if let Some(style) = highlight_id.style(&style.syntax) {
-            highlights.push((prev_len + range.start..prev_len + range.end, style));
-        }
-    }
-}
-
-fn new_paragraph(text: &mut String, list_stack: &mut Vec<(Option<u64>, bool)>) {
-    let mut is_subsequent_paragraph_of_list = false;
-    if let Some((_, has_content)) = list_stack.last_mut() {
-        if *has_content {
-            is_subsequent_paragraph_of_list = true;
-        } else {
-            *has_content = true;
-            return;
-        }
-    }
-
-    if !text.is_empty() {
-        if !text.ends_with('\n') {
-            text.push('\n');
-        }
-        text.push('\n');
-    }
-    for _ in 0..list_stack.len().saturating_sub(1) {
-        text.push_str("  ");
-    }
-    if is_subsequent_paragraph_of_list {
-        text.push_str("  ");
-    }
+    data
 }
 
 #[derive(Default)]
@@ -623,22 +445,7 @@ pub struct InfoPopover {
     symbol_range: RangeInEditor,
     pub blocks: Vec<HoverBlock>,
     language: Option<Arc<Language>>,
-    rendered_content: Option<RenderedInfo>,
-}
-
-#[derive(Debug, Clone)]
-struct RenderedInfo {
-    theme_id: usize,
-    text: String,
-    highlights: Vec<(Range<usize>, HighlightStyle)>,
-    region_ranges: Vec<Range<usize>>,
-    regions: Vec<RenderedRegion>,
-}
-
-#[derive(Debug, Clone)]
-struct RenderedRegion {
-    code: bool,
-    link_url: Option<String>,
+    rendered_content: Option<RichText>,
 }
 
 impl InfoPopover {
@@ -647,63 +454,24 @@ impl InfoPopover {
         style: &EditorStyle,
         cx: &mut ViewContext<Editor>,
     ) -> AnyElement<Editor> {
-        if let Some(rendered) = &self.rendered_content {
-            if rendered.theme_id != style.theme_id {
-                self.rendered_content = None;
-            }
-        }
-
         let rendered_content = self.rendered_content.get_or_insert_with(|| {
             render_blocks(
-                style.theme_id,
                 &self.blocks,
                 self.project.read(cx).languages(),
                 self.language.as_ref(),
-                style,
             )
         });
 
-        MouseEventHandler::new::<InfoPopover, _>(0, cx, |_, cx| {
-            let mut region_id = 0;
-            let view_id = cx.view_id();
-
+        MouseEventHandler::new::<InfoPopover, _>(0, cx, move |_, cx| {
             let code_span_background_color = style.document_highlight_read_background;
-            let regions = rendered_content.regions.clone();
             Flex::column()
                 .scrollable::<HoverBlock>(1, None, cx)
-                .with_child(
-                    Text::new(rendered_content.text.clone(), style.text.clone())
-                        .with_highlights(rendered_content.highlights.clone())
-                        .with_custom_runs(
-                            rendered_content.region_ranges.clone(),
-                            move |ix, bounds, cx| {
-                                region_id += 1;
-                                let region = regions[ix].clone();
-                                if let Some(url) = region.link_url {
-                                    cx.scene().push_cursor_region(CursorRegion {
-                                        bounds,
-                                        style: CursorStyle::PointingHand,
-                                    });
-                                    cx.scene().push_mouse_region(
-                                        MouseRegion::new::<Self>(view_id, region_id, bounds)
-                                            .on_click::<Editor, _>(
-                                                MouseButton::Left,
-                                                move |_, _, cx| cx.platform().open_url(&url),
-                                            ),
-                                    );
-                                }
-                                if region.code {
-                                    cx.scene().push_quad(gpui::Quad {
-                                        bounds,
-                                        background: Some(code_span_background_color),
-                                        border: Default::default(),
-                                        corner_radii: (2.0).into(),
-                                    });
-                                }
-                            },
-                        )
-                        .with_soft_wrap(true),
-                )
+                .with_child(rendered_content.element(
+                    style.syntax.clone(),
+                    style.text.clone(),
+                    code_span_background_color,
+                    cx,
+                ))
                 .contained()
                 .with_style(style.hover_popover.container)
         })
@@ -799,11 +567,12 @@ mod tests {
         InlayId,
     };
     use collections::BTreeSet;
-    use gpui::fonts::Weight;
+    use gpui::fonts::{HighlightStyle, Underline, Weight};
     use indoc::indoc;
     use language::{language_settings::InlayHintSettings, Diagnostic, DiagnosticSet};
     use lsp::LanguageServerId;
     use project::{HoverBlock, HoverBlockKind};
+    use rich_text::Highlight;
     use smol::stream::StreamExt;
     use unindent::Unindent;
     use util::test::marked_text_ranges;
@@ -1014,7 +783,7 @@ mod tests {
         .await;
 
         cx.condition(|editor, _| editor.hover_state.visible()).await;
-        cx.editor(|editor, cx| {
+        cx.editor(|editor, _| {
             let blocks = editor.hover_state.info_popover.clone().unwrap().blocks;
             assert_eq!(
                 blocks,
@@ -1024,8 +793,7 @@ mod tests {
                 }],
             );
 
-            let style = editor.style(cx);
-            let rendered = render_blocks(0, &blocks, &Default::default(), None, &style);
+            let rendered = render_blocks(&blocks, &Default::default(), None);
             assert_eq!(
                 rendered.text,
                 code_str.trim(),
@@ -1217,7 +985,7 @@ mod tests {
                 expected_styles,
             } in &rows[0..]
             {
-                let rendered = render_blocks(0, &blocks, &Default::default(), None, &style);
+                let rendered = render_blocks(&blocks, &Default::default(), None);
 
                 let (expected_text, ranges) = marked_text_ranges(expected_marked_text, false);
                 let expected_highlights = ranges
@@ -1228,8 +996,21 @@ mod tests {
                     rendered.text, expected_text,
                     "wrong text for input {blocks:?}"
                 );
+
+                let rendered_highlights: Vec<_> = rendered
+                    .highlights
+                    .iter()
+                    .filter_map(|(range, highlight)| {
+                        let style = match highlight {
+                            Highlight::Id(id) => id.style(&style.syntax)?,
+                            Highlight::Highlight(style) => style.clone(),
+                        };
+                        Some((range.clone(), style))
+                    })
+                    .collect();
+
                 assert_eq!(
-                    rendered.highlights, expected_highlights,
+                    rendered_highlights, expected_highlights,
                     "wrong highlights for input {blocks:?}"
                 );
             }

crates/editor/src/items.rs

@@ -17,7 +17,7 @@ use language::{
     SelectionGoal,
 };
 use project::{search::SearchQuery, FormatTrigger, Item as _, Project, ProjectPath};
-use rpc::proto::{self, update_view};
+use rpc::proto::{self, update_view, PeerId};
 use smallvec::SmallVec;
 use std::{
     borrow::Cow,
@@ -156,13 +156,9 @@ impl FollowableItem for Editor {
         }))
     }
 
-    fn set_leader_replica_id(
-        &mut self,
-        leader_replica_id: Option<u16>,
-        cx: &mut ViewContext<Self>,
-    ) {
-        self.leader_replica_id = leader_replica_id;
-        if self.leader_replica_id.is_some() {
+    fn set_leader_peer_id(&mut self, leader_peer_id: Option<PeerId>, cx: &mut ViewContext<Self>) {
+        self.leader_peer_id = leader_peer_id;
+        if self.leader_peer_id.is_some() {
             self.buffer.update(cx, |buffer, cx| {
                 buffer.remove_active_selections(cx);
             });
@@ -309,6 +305,10 @@ impl FollowableItem for Editor {
             _ => false,
         }
     }
+
+    fn is_project_item(&self, _cx: &AppContext) -> bool {
+        true
+    }
 }
 
 async fn update_editor_from_message(
@@ -995,8 +995,10 @@ impl SearchableItem for Editor {
             joined_chunks.into()
         };
 
-        if let Some(replacement) = query.replacement(&text) {
-            self.edit([(identifier.clone(), Arc::from(&*replacement))], cx);
+        if let Some(replacement) = query.replacement_for(&text) {
+            self.transact(cx, |this, cx| {
+                this.edit([(identifier.clone(), Arc::from(&*replacement))], cx);
+            });
         }
     }
     fn match_index_for_direction(

crates/editor/src/scroll/scroll_amount.rs

@@ -15,9 +15,13 @@ impl ScrollAmount {
             Self::Line(count) => *count,
             Self::Page(count) => editor
                 .visible_line_count()
-                // subtract one to leave an anchor line
-                // round towards zero (so page-up and page-down are symmetric)
-                .map(|l| (l * count).trunc() - count.signum())
+                .map(|mut l| {
+                    // for full pages subtract one to leave an anchor line
+                    if count.abs() == 1.0 {
+                        l -= 1.0
+                    }
+                    (l * count).trunc()
+                })
                 .unwrap_or(0.),
         }
     }

crates/editor/src/test/editor_test_context.rs

@@ -3,8 +3,8 @@ use crate::{
 };
 use futures::Future;
 use gpui::{
-    keymap_matcher::Keystroke, AnyWindowHandle, AppContext, ContextHandle, ModelContext,
-    ViewContext, ViewHandle,
+    executor::Foreground, keymap_matcher::Keystroke, AnyWindowHandle, AppContext, ContextHandle,
+    ModelContext, ViewContext, ViewHandle,
 };
 use indoc::indoc;
 use language::{Buffer, BufferSnapshot};
@@ -114,6 +114,7 @@ impl<'a> EditorTestContext<'a> {
         let keystroke = Keystroke::parse(keystroke_text).unwrap();
 
         self.cx.dispatch_keystroke(self.window, keystroke, false);
+
         keystroke_under_test_handle
     }
 
@@ -126,6 +127,16 @@ impl<'a> EditorTestContext<'a> {
         for keystroke_text in keystroke_texts.into_iter() {
             self.simulate_keystroke(keystroke_text);
         }
+        // it is common for keyboard shortcuts to kick off async actions, so this ensures that they are complete
+        // before returning.
+        // NOTE: we don't do this in simulate_keystroke() because a possible cause of bugs is that typing too
+        // quickly races with async actions.
+        if let Foreground::Deterministic { cx_id: _, executor } = self.cx.foreground().as_ref() {
+            executor.run_until_parked();
+        } else {
+            unreachable!();
+        }
+
         keystrokes_under_test_handle
     }
 

crates/feedback/Cargo.toml

@@ -33,7 +33,7 @@ lazy_static.workspace = true
 postage.workspace = true
 serde.workspace = true
 serde_derive.workspace = true
-sysinfo = "0.27.1"
+sysinfo.workspace = true
 tree-sitter-markdown = { git = "https://github.com/MDeiml/tree-sitter-markdown", rev = "330ecab87a3e3a7211ac69bbadc19eabecdb1cca" }
 urlencoding = "2.1.2"
 

crates/file_finder/Cargo.toml

@@ -10,6 +10,7 @@ doctest = false
 
 [dependencies]
 editor = { path = "../editor" }
+collections = { path = "../collections" }
 fuzzy = { path = "../fuzzy" }
 gpui = { path = "../gpui" }
 menu = { path = "../menu" }

crates/file_finder/src/file_finder.rs

@@ -1,5 +1,6 @@
+use collections::HashMap;
 use editor::{scroll::autoscroll::Autoscroll, Bias, Editor};
-use fuzzy::PathMatch;
+use fuzzy::{CharBag, PathMatch, PathMatchCandidate};
 use gpui::{
     actions, elements::*, AppContext, ModelHandle, MouseState, Task, ViewContext, WeakViewHandle,
 };
@@ -32,38 +33,124 @@ pub struct FileFinderDelegate {
     history_items: Vec<FoundPath>,
 }
 
-#[derive(Debug)]
-enum Matches {
-    History(Vec<FoundPath>),
-    Search(Vec<PathMatch>),
+#[derive(Debug, Default)]
+struct Matches {
+    history: Vec<(FoundPath, Option<PathMatch>)>,
+    search: Vec<PathMatch>,
 }
 
 #[derive(Debug)]
 enum Match<'a> {
-    History(&'a FoundPath),
+    History(&'a FoundPath, Option<&'a PathMatch>),
     Search(&'a PathMatch),
 }
 
 impl Matches {
     fn len(&self) -> usize {
-        match self {
-            Self::History(items) => items.len(),
-            Self::Search(items) => items.len(),
-        }
+        self.history.len() + self.search.len()
     }
 
     fn get(&self, index: usize) -> Option<Match<'_>> {
-        match self {
-            Self::History(items) => items.get(index).map(Match::History),
-            Self::Search(items) => items.get(index).map(Match::Search),
+        if index < self.history.len() {
+            self.history
+                .get(index)
+                .map(|(path, path_match)| Match::History(path, path_match.as_ref()))
+        } else {
+            self.search
+                .get(index - self.history.len())
+                .map(Match::Search)
+        }
+    }
+
+    fn push_new_matches(
+        &mut self,
+        history_items: &Vec<FoundPath>,
+        query: &PathLikeWithPosition<FileSearchQuery>,
+        mut new_search_matches: Vec<PathMatch>,
+        extend_old_matches: bool,
+    ) {
+        let matching_history_paths = matching_history_item_paths(history_items, query);
+        new_search_matches
+            .retain(|path_match| !matching_history_paths.contains_key(&path_match.path));
+        let history_items_to_show = history_items
+            .iter()
+            .filter_map(|history_item| {
+                Some((
+                    history_item.clone(),
+                    Some(
+                        matching_history_paths
+                            .get(&history_item.project.path)?
+                            .clone(),
+                    ),
+                ))
+            })
+            .collect::<Vec<_>>();
+        self.history = history_items_to_show;
+        if extend_old_matches {
+            self.search
+                .retain(|path_match| !matching_history_paths.contains_key(&path_match.path));
+            util::extend_sorted(
+                &mut self.search,
+                new_search_matches.into_iter(),
+                100,
+                |a, b| b.cmp(a),
+            )
+        } else {
+            self.search = new_search_matches;
         }
     }
 }
 
-impl Default for Matches {
-    fn default() -> Self {
-        Self::History(Vec::new())
+fn matching_history_item_paths(
+    history_items: &Vec<FoundPath>,
+    query: &PathLikeWithPosition<FileSearchQuery>,
+) -> HashMap<Arc<Path>, PathMatch> {
+    let history_items_by_worktrees = history_items
+        .iter()
+        .filter_map(|found_path| {
+            let candidate = PathMatchCandidate {
+                path: &found_path.project.path,
+                // Only match history items names, otherwise their paths may match too many queries, producing false positives.
+                // E.g. `foo` would match both `something/foo/bar.rs` and `something/foo/foo.rs` and if the former is a history item,
+                // it would be shown first always, despite the latter being a better match.
+                char_bag: CharBag::from_iter(
+                    found_path
+                        .project
+                        .path
+                        .file_name()?
+                        .to_string_lossy()
+                        .to_lowercase()
+                        .chars(),
+                ),
+            };
+            Some((found_path.project.worktree_id, candidate))
+        })
+        .fold(
+            HashMap::default(),
+            |mut candidates, (worktree_id, new_candidate)| {
+                candidates
+                    .entry(worktree_id)
+                    .or_insert_with(Vec::new)
+                    .push(new_candidate);
+                candidates
+            },
+        );
+    let mut matching_history_paths = HashMap::default();
+    for (worktree, candidates) in history_items_by_worktrees {
+        let max_results = candidates.len() + 1;
+        matching_history_paths.extend(
+            fuzzy::match_fixed_path_set(
+                candidates,
+                worktree.to_usize(),
+                query.path_like.path_query(),
+                false,
+                max_results,
+            )
+            .into_iter()
+            .map(|path_match| (Arc::clone(&path_match.path), path_match)),
+        );
     }
+    matching_history_paths
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -81,66 +168,96 @@ impl FoundPath {
 actions!(file_finder, [Toggle]);
 
 pub fn init(cx: &mut AppContext) {
-    cx.add_action(toggle_file_finder);
+    cx.add_action(toggle_or_cycle_file_finder);
     FileFinder::init(cx);
 }
 
 const MAX_RECENT_SELECTIONS: usize = 20;
 
-fn toggle_file_finder(workspace: &mut Workspace, _: &Toggle, cx: &mut ViewContext<Workspace>) {
-    workspace.toggle_modal(cx, |workspace, cx| {
-        let project = workspace.project().read(cx);
+fn toggle_or_cycle_file_finder(
+    workspace: &mut Workspace,
+    _: &Toggle,
+    cx: &mut ViewContext<Workspace>,
+) {
+    match workspace.modal::<FileFinder>() {
+        Some(file_finder) => file_finder.update(cx, |file_finder, cx| {
+            let current_index = file_finder.delegate().selected_index();
+            file_finder.select_next(&menu::SelectNext, cx);
+            let new_index = file_finder.delegate().selected_index();
+            if current_index == new_index {
+                file_finder.select_first(&menu::SelectFirst, cx);
+            }
+        }),
+        None => {
+            workspace.toggle_modal(cx, |workspace, cx| {
+                let project = workspace.project().read(cx);
 
-        let currently_opened_path = workspace
-            .active_item(cx)
-            .and_then(|item| item.project_path(cx))
-            .map(|project_path| {
-                let abs_path = project
-                    .worktree_for_id(project_path.worktree_id, cx)
-                    .map(|worktree| worktree.read(cx).abs_path().join(&project_path.path));
-                FoundPath::new(project_path, abs_path)
-            });
+                let currently_opened_path = workspace
+                    .active_item(cx)
+                    .and_then(|item| item.project_path(cx))
+                    .map(|project_path| {
+                        let abs_path = project
+                            .worktree_for_id(project_path.worktree_id, cx)
+                            .map(|worktree| worktree.read(cx).abs_path().join(&project_path.path));
+                        FoundPath::new(project_path, abs_path)
+                    });
 
-        // if exists, bubble the currently opened path to the top
-        let history_items = currently_opened_path
-            .clone()
-            .into_iter()
-            .chain(
-                workspace
-                    .recent_navigation_history(Some(MAX_RECENT_SELECTIONS), cx)
+                // if exists, bubble the currently opened path to the top
+                let history_items = currently_opened_path
+                    .clone()
                     .into_iter()
-                    .filter(|(history_path, _)| {
-                        Some(history_path)
-                            != currently_opened_path
-                                .as_ref()
-                                .map(|found_path| &found_path.project)
-                    })
-                    .filter(|(_, history_abs_path)| {
-                        history_abs_path.as_ref()
-                            != currently_opened_path
-                                .as_ref()
-                                .and_then(|found_path| found_path.absolute.as_ref())
-                    })
-                    .map(|(history_path, abs_path)| FoundPath::new(history_path, abs_path)),
-            )
-            .collect();
+                    .chain(
+                        workspace
+                            .recent_navigation_history(Some(MAX_RECENT_SELECTIONS), cx)
+                            .into_iter()
+                            .filter(|(history_path, _)| {
+                                Some(history_path)
+                                    != currently_opened_path
+                                        .as_ref()
+                                        .map(|found_path| &found_path.project)
+                            })
+                            .filter(|(_, history_abs_path)| {
+                                history_abs_path.as_ref()
+                                    != currently_opened_path
+                                        .as_ref()
+                                        .and_then(|found_path| found_path.absolute.as_ref())
+                            })
+                            .filter(|(_, history_abs_path)| match history_abs_path {
+                                Some(abs_path) => history_file_exists(abs_path),
+                                None => true,
+                            })
+                            .map(|(history_path, abs_path)| FoundPath::new(history_path, abs_path)),
+                    )
+                    .collect();
 
-        let project = workspace.project().clone();
-        let workspace = cx.handle().downgrade();
-        let finder = cx.add_view(|cx| {
-            Picker::new(
-                FileFinderDelegate::new(
-                    workspace,
-                    project,
-                    currently_opened_path,
-                    history_items,
-                    cx,
-                ),
-                cx,
-            )
-        });
-        finder
-    });
+                let project = workspace.project().clone();
+                let workspace = cx.handle().downgrade();
+                let finder = cx.add_view(|cx| {
+                    Picker::new(
+                        FileFinderDelegate::new(
+                            workspace,
+                            project,
+                            currently_opened_path,
+                            history_items,
+                            cx,
+                        ),
+                        cx,
+                    )
+                });
+                finder
+            });
+        }
+    }
+}
+
+#[cfg(not(test))]
+fn history_file_exists(abs_path: &PathBuf) -> bool {
+    abs_path.exists()
+}
+
+#[cfg(test)]
+fn history_file_exists(abs_path: &PathBuf) -> bool {
+    !abs_path.ends_with("nonexistent.rs")
 }
 
 pub enum Event {
@@ -255,24 +372,14 @@ impl FileFinderDelegate {
     ) {
         if search_id >= self.latest_search_id {
             self.latest_search_id = search_id;
-            if self.latest_search_did_cancel
+            let extend_old_matches = self.latest_search_did_cancel
                 && Some(query.path_like.path_query())
                     == self
                         .latest_search_query
                         .as_ref()
-                        .map(|query| query.path_like.path_query())
-            {
-                match &mut self.matches {
-                    Matches::History(_) => self.matches = Matches::Search(matches),
-                    Matches::Search(search_matches) => {
-                        util::extend_sorted(search_matches, matches.into_iter(), 100, |a, b| {
-                            b.cmp(a)
-                        })
-                    }
-                }
-            } else {
-                self.matches = Matches::Search(matches);
-            }
+                        .map(|query| query.path_like.path_query());
+            self.matches
+                .push_new_matches(&self.history_items, &query, matches, extend_old_matches);
             self.latest_search_query = Some(query);
             self.latest_search_did_cancel = did_cancel;
             cx.notify();
@@ -286,7 +393,7 @@ impl FileFinderDelegate {
         ix: usize,
     ) -> (String, Vec<usize>, String, Vec<usize>) {
         let (file_name, file_name_positions, full_path, full_path_positions) = match path_match {
-            Match::History(found_path) => {
+            Match::History(found_path, found_path_match) => {
                 let worktree_id = found_path.project.worktree_id;
                 let project_relative_path = &found_path.project.path;
                 let has_worktree = self
@@ -318,14 +425,22 @@ impl FileFinderDelegate {
                         path = Arc::from(absolute_path.as_path());
                     }
                 }
-                self.labels_for_path_match(&PathMatch {
+
+                let mut path_match = PathMatch {
                     score: ix as f64,
                     positions: Vec::new(),
                     worktree_id: worktree_id.to_usize(),
                     path,
                     path_prefix: "".into(),
                     distance_to_relative_ancestor: usize::MAX,
-                })
+                };
+                if let Some(found_path_match) = found_path_match {
+                    path_match
+                        .positions
+                        .extend(found_path_match.positions.iter())
+                }
+
+                self.labels_for_path_match(&path_match)
             }
             Match::Search(path_match) => self.labels_for_path_match(path_match),
         };
@@ -406,23 +521,21 @@ impl PickerDelegate for FileFinderDelegate {
         if raw_query.is_empty() {
             let project = self.project.read(cx);
             self.latest_search_id = post_inc(&mut self.search_count);
-            self.matches = Matches::History(
-                self.history_items
+            self.matches = Matches {
+                history: self
+                    .history_items
                     .iter()
                     .filter(|history_item| {
                         project
                             .worktree_for_id(history_item.project.worktree_id, cx)
                             .is_some()
-                            || (project.is_local()
-                                && history_item
-                                    .absolute
-                                    .as_ref()
-                                    .filter(|abs_path| abs_path.exists())
-                                    .is_some())
+                            || (project.is_local() && history_item.absolute.is_some())
                     })
                     .cloned()
+                    .map(|p| (p, None))
                     .collect(),
-            );
+                search: Vec::new(),
+            };
             cx.notify();
             Task::ready(())
         } else {
@@ -454,7 +567,7 @@ impl PickerDelegate for FileFinderDelegate {
                         }
                     };
                     match m {
-                        Match::History(history_match) => {
+                        Match::History(history_match, _) => {
                             let worktree_id = history_match.project.worktree_id;
                             if workspace
                                 .project()
@@ -866,11 +979,11 @@ mod tests {
 
         finder.update(cx, |finder, cx| {
             let delegate = finder.delegate_mut();
-            let matches = match &delegate.matches {
-                Matches::Search(path_matches) => path_matches,
-                _ => panic!("Search matches expected"),
-            }
-            .clone();
+            assert!(
+                delegate.matches.history.is_empty(),
+                "Search matches expected"
+            );
+            let matches = delegate.matches.search.clone();
 
             // Simulate a search being cancelled after the time limit,
             // returning only a subset of the matches that would have been found.
@@ -893,12 +1006,11 @@ mod tests {
                 cx,
             );
 
-            match &delegate.matches {
-                Matches::Search(new_matches) => {
-                    assert_eq!(new_matches.as_slice(), &matches[0..4])
-                }
-                _ => panic!("Search matches expected"),
-            };
+            assert!(
+                delegate.matches.history.is_empty(),
+                "Search matches expected"
+            );
+            assert_eq!(delegate.matches.search.as_slice(), &matches[0..4]);
         });
     }
 
@@ -1006,10 +1118,11 @@ mod tests {
         cx.read(|cx| {
             let finder = finder.read(cx);
             let delegate = finder.delegate();
-            let matches = match &delegate.matches {
-                Matches::Search(path_matches) => path_matches,
-                _ => panic!("Search matches expected"),
-            };
+            assert!(
+                delegate.matches.history.is_empty(),
+                "Search matches expected"
+            );
+            let matches = delegate.matches.search.clone();
             assert_eq!(matches.len(), 1);
 
             let (file_name, file_name_positions, full_path, full_path_positions) =
@@ -1088,10 +1201,11 @@ mod tests {
 
         finder.read_with(cx, |f, _| {
             let delegate = f.delegate();
-            let matches = match &delegate.matches {
-                Matches::Search(path_matches) => path_matches,
-                _ => panic!("Search matches expected"),
-            };
+            assert!(
+                delegate.matches.history.is_empty(),
+                "Search matches expected"
+            );
+            let matches = delegate.matches.search.clone();
             assert_eq!(matches[0].path.as_ref(), Path::new("dir2/a.txt"));
             assert_eq!(matches[1].path.as_ref(), Path::new("dir1/a.txt"));
         });
@@ -1459,6 +1573,451 @@ mod tests {
         );
     }
 
+    #[gpui::test]
+    async fn test_toggle_panel_new_selections(
+        deterministic: Arc<gpui::executor::Deterministic>,
+        cx: &mut gpui::TestAppContext,
+    ) {
+        let app_state = init_test(cx);
+
+        app_state
+            .fs
+            .as_fake()
+            .insert_tree(
+                "/src",
+                json!({
+                    "test": {
+                        "first.rs": "// First Rust file",
+                        "second.rs": "// Second Rust file",
+                        "third.rs": "// Third Rust file",
+                    }
+                }),
+            )
+            .await;
+
+        let project = Project::test(app_state.fs.clone(), ["/src".as_ref()], cx).await;
+        let window = cx.add_window(|cx| Workspace::test_new(project, cx));
+        let workspace = window.root(cx);
+
+        // generate some history to select from
+        open_close_queried_buffer(
+            "fir",
+            1,
+            "first.rs",
+            window.into(),
+            &workspace,
+            &deterministic,
+            cx,
+        )
+        .await;
+        open_close_queried_buffer(
+            "sec",
+            1,
+            "second.rs",
+            window.into(),
+            &workspace,
+            &deterministic,
+            cx,
+        )
+        .await;
+        open_close_queried_buffer(
+            "thi",
+            1,
+            "third.rs",
+            window.into(),
+            &workspace,
+            &deterministic,
+            cx,
+        )
+        .await;
+        let current_history = open_close_queried_buffer(
+            "sec",
+            1,
+            "second.rs",
+            window.into(),
+            &workspace,
+            &deterministic,
+            cx,
+        )
+        .await;
+
+        for expected_selected_index in 0..current_history.len() {
+            cx.dispatch_action(window.into(), Toggle);
+            let selected_index = cx.read(|cx| {
+                workspace
+                    .read(cx)
+                    .modal::<FileFinder>()
+                    .unwrap()
+                    .read(cx)
+                    .delegate()
+                    .selected_index()
+            });
+            assert_eq!(
+                selected_index, expected_selected_index,
+                "Should select the next item in the history"
+            );
+        }
+
+        cx.dispatch_action(window.into(), Toggle);
+        let selected_index = cx.read(|cx| {
+            workspace
+                .read(cx)
+                .modal::<FileFinder>()
+                .unwrap()
+                .read(cx)
+                .delegate()
+                .selected_index()
+        });
+        assert_eq!(
+            selected_index, 0,
+            "Should wrap around the history and start all over"
+        );
+    }
+
+    #[gpui::test]
+    async fn test_search_preserves_history_items(
+        deterministic: Arc<gpui::executor::Deterministic>,
+        cx: &mut gpui::TestAppContext,
+    ) {
+        let app_state = init_test(cx);
+
+        app_state
+            .fs
+            .as_fake()
+            .insert_tree(
+                "/src",
+                json!({
+                    "test": {
+                        "first.rs": "// First Rust file",
+                        "second.rs": "// Second Rust file",
+                        "third.rs": "// Third Rust file",
+                        "fourth.rs": "// Fourth Rust file",
+                    }
+                }),
+            )
+            .await;
+
+        let project = Project::test(app_state.fs.clone(), ["/src".as_ref()], cx).await;
+        let window = cx.add_window(|cx| Workspace::test_new(project, cx));
+        let workspace = window.root(cx);
+        let worktree_id = cx.read(|cx| {
+            let worktrees = workspace.read(cx).worktrees(cx).collect::<Vec<_>>();
+            assert_eq!(worktrees.len(), 1,);
+
+            WorktreeId::from_usize(worktrees[0].id())
+        });
+
+        // generate some history to select from
+        open_close_queried_buffer(
+            "fir",
+            1,
+            "first.rs",
+            window.into(),
+            &workspace,
+            &deterministic,
+            cx,
+        )
+        .await;
+        open_close_queried_buffer(
+            "sec",
+            1,
+            "second.rs",
+            window.into(),
+            &workspace,
+            &deterministic,
+            cx,
+        )
+        .await;
+        open_close_queried_buffer(
+            "thi",
+            1,
+            "third.rs",
+            window.into(),
+            &workspace,
+            &deterministic,
+            cx,
+        )
+        .await;
+        open_close_queried_buffer(
+            "sec",
+            1,
+            "second.rs",
+            window.into(),
+            &workspace,
+            &deterministic,
+            cx,
+        )
+        .await;
+
+        cx.dispatch_action(window.into(), Toggle);
+        let first_query = "f";
+        let finder = cx.read(|cx| workspace.read(cx).modal::<FileFinder>().unwrap());
+        finder
+            .update(cx, |finder, cx| {
+                finder
+                    .delegate_mut()
+                    .update_matches(first_query.to_string(), cx)
+            })
+            .await;
+        finder.read_with(cx, |finder, _| {
+            let delegate = finder.delegate();
+            assert_eq!(delegate.matches.history.len(), 1, "Only one history item contains {first_query}, it should be present and others should be filtered out");
+            let history_match = delegate.matches.history.first().unwrap();
+            assert!(history_match.1.is_some(), "Should have path matches for history items after querying");
+            assert_eq!(history_match.0, FoundPath::new(
+                ProjectPath {
+                    worktree_id,
+                    path: Arc::from(Path::new("test/first.rs")),
+                },
+                Some(PathBuf::from("/src/test/first.rs"))
+            ));
+            assert_eq!(delegate.matches.search.len(), 1, "Only one non-history item contains {first_query}, it should be present");
+            assert_eq!(delegate.matches.search.first().unwrap().path.as_ref(), Path::new("test/fourth.rs"));
+        });
+
+        let second_query = "fsdasdsa";
+        let finder = cx.read(|cx| workspace.read(cx).modal::<FileFinder>().unwrap());
+        finder
+            .update(cx, |finder, cx| {
+                finder
+                    .delegate_mut()
+                    .update_matches(second_query.to_string(), cx)
+            })
+            .await;
+        finder.read_with(cx, |finder, _| {
+            let delegate = finder.delegate();
+            assert!(
+                delegate.matches.history.is_empty(),
+                "No history entries should match {second_query}"
+            );
+            assert!(
+                delegate.matches.search.is_empty(),
+                "No search entries should match {second_query}"
+            );
+        });
+
+        let first_query_again = first_query;
+        let finder = cx.read(|cx| workspace.read(cx).modal::<FileFinder>().unwrap());
+        finder
+            .update(cx, |finder, cx| {
+                finder
+                    .delegate_mut()
+                    .update_matches(first_query_again.to_string(), cx)
+            })
+            .await;
+        finder.read_with(cx, |finder, _| {
+            let delegate = finder.delegate();
+            assert_eq!(delegate.matches.history.len(), 1, "Only one history item contains {first_query_again}, it should be present and others should be filtered out, even after non-matching query");
+            let history_match = delegate.matches.history.first().unwrap();
+            assert!(history_match.1.is_some(), "Should have path matches for history items after querying");
+            assert_eq!(history_match.0, FoundPath::new(
+                ProjectPath {
+                    worktree_id,
+                    path: Arc::from(Path::new("test/first.rs")),
+                },
+                Some(PathBuf::from("/src/test/first.rs"))
+            ));
+            assert_eq!(delegate.matches.search.len(), 1, "Only one non-history item contains {first_query_again}, it should be present, even after non-matching query");
+            assert_eq!(delegate.matches.search.first().unwrap().path.as_ref(), Path::new("test/fourth.rs"));
+        });
+    }
+
+    #[gpui::test]
+    async fn test_history_items_vs_very_good_external_match(
+        deterministic: Arc<gpui::executor::Deterministic>,
+        cx: &mut gpui::TestAppContext,
+    ) {
+        let app_state = init_test(cx);
+
+        app_state
+            .fs
+            .as_fake()
+            .insert_tree(
+                "/src",
+                json!({
+                    "collab_ui": {
+                        "first.rs": "// First Rust file",
+                        "second.rs": "// Second Rust file",
+                        "third.rs": "// Third Rust file",
+                        "collab_ui.rs": "// Fourth Rust file",
+                    }
+                }),
+            )
+            .await;
+
+        let project = Project::test(app_state.fs.clone(), ["/src".as_ref()], cx).await;
+        let window = cx.add_window(|cx| Workspace::test_new(project, cx));
+        let workspace = window.root(cx);
+        // generate some history to select from
+        open_close_queried_buffer(
+            "fir",
+            1,
+            "first.rs",
+            window.into(),
+            &workspace,
+            &deterministic,
+            cx,
+        )
+        .await;
+        open_close_queried_buffer(
+            "sec",
+            1,
+            "second.rs",
+            window.into(),
+            &workspace,
+            &deterministic,
+            cx,
+        )
+        .await;
+        open_close_queried_buffer(
+            "thi",
+            1,
+            "third.rs",
+            window.into(),
+            &workspace,
+            &deterministic,
+            cx,
+        )
+        .await;
+        open_close_queried_buffer(
+            "sec",
+            1,
+            "second.rs",
+            window.into(),
+            &workspace,
+            &deterministic,
+            cx,
+        )
+        .await;
+
+        cx.dispatch_action(window.into(), Toggle);
+        let query = "collab_ui";
+        let finder = cx.read(|cx| workspace.read(cx).modal::<FileFinder>().unwrap());
+        finder
+            .update(cx, |finder, cx| {
+                finder.delegate_mut().update_matches(query.to_string(), cx)
+            })
+            .await;
+        finder.read_with(cx, |finder, _| {
+            let delegate = finder.delegate();
+            assert!(
+                delegate.matches.history.is_empty(),
+                "History items should not math query {query}, they should be matched by name only"
+            );
+
+            let search_entries = delegate
+                .matches
+                .search
+                .iter()
+                .map(|path_match| path_match.path.to_path_buf())
+                .collect::<Vec<_>>();
+            assert_eq!(
+                search_entries,
+                vec![
+                    PathBuf::from("collab_ui/collab_ui.rs"),
+                    PathBuf::from("collab_ui/third.rs"),
+                    PathBuf::from("collab_ui/first.rs"),
+                    PathBuf::from("collab_ui/second.rs"),
+                ],
+                "Despite all search results having the same directory name, the most matching one should be on top"
+            );
+        });
+    }
+
+    #[gpui::test]
+    async fn test_nonexistent_history_items_not_shown(
+        deterministic: Arc<gpui::executor::Deterministic>,
+        cx: &mut gpui::TestAppContext,
+    ) {
+        let app_state = init_test(cx);
+
+        app_state
+            .fs
+            .as_fake()
+            .insert_tree(
+                "/src",
+                json!({
+                    "test": {
+                        "first.rs": "// First Rust file",
+                        "nonexistent.rs": "// Second Rust file",
+                        "third.rs": "// Third Rust file",
+                    }
+                }),
+            )
+            .await;
+
+        let project = Project::test(app_state.fs.clone(), ["/src".as_ref()], cx).await;
+        let window = cx.add_window(|cx| Workspace::test_new(project, cx));
+        let workspace = window.root(cx);
+        // generate some history to select from
+        open_close_queried_buffer(
+            "fir",
+            1,
+            "first.rs",
+            window.into(),
+            &workspace,
+            &deterministic,
+            cx,
+        )
+        .await;
+        open_close_queried_buffer(
+            "non",
+            1,
+            "nonexistent.rs",
+            window.into(),
+            &workspace,
+            &deterministic,
+            cx,
+        )
+        .await;
+        open_close_queried_buffer(
+            "thi",
+            1,
+            "third.rs",
+            window.into(),
+            &workspace,
+            &deterministic,
+            cx,
+        )
+        .await;
+        open_close_queried_buffer(
+            "fir",
+            1,
+            "first.rs",
+            window.into(),
+            &workspace,
+            &deterministic,
+            cx,
+        )
+        .await;
+
+        cx.dispatch_action(window.into(), Toggle);
+        let query = "rs";
+        let finder = cx.read(|cx| workspace.read(cx).modal::<FileFinder>().unwrap());
+        finder
+            .update(cx, |finder, cx| {
+                finder.delegate_mut().update_matches(query.to_string(), cx)
+            })
+            .await;
+        finder.read_with(cx, |finder, _| {
+            let delegate = finder.delegate();
+            let history_entries = delegate
+                .matches
+                .history
+                .iter()
+                .map(|(_, path_match)| path_match.as_ref().expect("should have a path match").path.to_path_buf())
+                .collect::<Vec<_>>();
+            assert_eq!(
+                history_entries,
+                vec![
+                    PathBuf::from("test/first.rs"),
+                    PathBuf::from("test/third.rs"),
+                ],
+                "Should have all opened files in the history, except the ones that do not exist on disk"
+            );
+        });
+    }
+
     async fn open_close_queried_buffer(
         input: &str,
         expected_matches: usize,
@@ -1528,13 +2087,8 @@ mod tests {
         let active_pane = cx.read(|cx| workspace.read(cx).active_pane().clone());
         active_pane
             .update(cx, |pane, cx| {
-                pane.close_active_item(
-                    &workspace::CloseActiveItem {
-                        save_behavior: None,
-                    },
-                    cx,
-                )
-                .unwrap()
+                pane.close_active_item(&workspace::CloseActiveItem { save_intent: None }, cx)
+                    .unwrap()
             })
             .await
             .unwrap();

crates/fs/Cargo.toml

@@ -9,8 +9,6 @@ path = "src/fs.rs"
 
 [dependencies]
 collections = { path = "../collections" }
-gpui = { path = "../gpui" }
-lsp = { path = "../lsp" }
 rope = { path = "../rope" }
 text = { path = "../text" }
 util = { path = "../util" }
@@ -34,8 +32,10 @@ log.workspace = true
 libc = "0.2"
 time.workspace = true
 
+gpui = { path = "../gpui", optional = true}
+
 [dev-dependencies]
 gpui = { path = "../gpui", features = ["test-support"] }
 
 [features]
-test-support = []
+test-support = ["gpui/test-support"]

crates/fs/src/fs.rs

@@ -93,33 +93,6 @@ pub struct Metadata {
     pub is_dir: bool,
 }
 
-impl From<lsp::CreateFileOptions> for CreateOptions {
-    fn from(options: lsp::CreateFileOptions) -> Self {
-        Self {
-            overwrite: options.overwrite.unwrap_or(false),
-            ignore_if_exists: options.ignore_if_exists.unwrap_or(false),
-        }
-    }
-}
-
-impl From<lsp::RenameFileOptions> for RenameOptions {
-    fn from(options: lsp::RenameFileOptions) -> Self {
-        Self {
-            overwrite: options.overwrite.unwrap_or(false),
-            ignore_if_exists: options.ignore_if_exists.unwrap_or(false),
-        }
-    }
-}
-
-impl From<lsp::DeleteFileOptions> for RemoveOptions {
-    fn from(options: lsp::DeleteFileOptions) -> Self {
-        Self {
-            recursive: options.recursive.unwrap_or(false),
-            ignore_if_not_exists: options.ignore_if_not_exists.unwrap_or(false),
-        }
-    }
-}
-
 pub struct RealFs;
 
 #[async_trait::async_trait]
@@ -507,7 +480,7 @@ impl FakeFs {
         state.emit_event(&[path]);
     }
 
-    fn write_file_internal(&self, path: impl AsRef<Path>, content: String) -> Result<()> {
+    pub fn write_file_internal(&self, path: impl AsRef<Path>, content: String) -> Result<()> {
         let mut state = self.state.lock();
         let path = path.as_ref();
         let inode = state.next_inode;

crates/fuzzy/src/fuzzy.rs

@@ -4,5 +4,7 @@ mod paths;
 mod strings;
 
 pub use char_bag::CharBag;
-pub use paths::{match_path_sets, PathMatch, PathMatchCandidate, PathMatchCandidateSet};
+pub use paths::{
+    match_fixed_path_set, match_path_sets, PathMatch, PathMatchCandidate, PathMatchCandidateSet,
+};
 pub use strings::{match_strings, StringMatch, StringMatchCandidate};

crates/fuzzy/src/matcher.rs

@@ -441,7 +441,7 @@ mod tests {
                 score,
                 worktree_id: 0,
                 positions: Vec::new(),
-                path: candidate.path.clone(),
+                path: Arc::from(candidate.path),
                 path_prefix: "".into(),
                 distance_to_relative_ancestor: usize::MAX,
             },

crates/fuzzy/src/paths.rs

@@ -14,7 +14,7 @@ use crate::{
 
 #[derive(Clone, Debug)]
 pub struct PathMatchCandidate<'a> {
-    pub path: &'a Arc<Path>,
+    pub path: &'a Path,
     pub char_bag: CharBag,
 }
 
@@ -90,6 +90,44 @@ impl Ord for PathMatch {
     }
 }
 
+pub fn match_fixed_path_set(
+    candidates: Vec<PathMatchCandidate>,
+    worktree_id: usize,
+    query: &str,
+    smart_case: bool,
+    max_results: usize,
+) -> Vec<PathMatch> {
+    let lowercase_query = query.to_lowercase().chars().collect::<Vec<_>>();
+    let query = query.chars().collect::<Vec<_>>();
+    let query_char_bag = CharBag::from(&lowercase_query[..]);
+
+    let mut matcher = Matcher::new(
+        &query,
+        &lowercase_query,
+        query_char_bag,
+        smart_case,
+        max_results,
+    );
+
+    let mut results = Vec::new();
+    matcher.match_candidates(
+        &[],
+        &[],
+        candidates.into_iter(),
+        &mut results,
+        &AtomicBool::new(false),
+        |candidate, score| PathMatch {
+            score,
+            worktree_id,
+            positions: Vec::new(),
+            path: Arc::from(candidate.path),
+            path_prefix: Arc::from(""),
+            distance_to_relative_ancestor: usize::MAX,
+        },
+    );
+    results
+}
+
 pub async fn match_path_sets<'a, Set: PathMatchCandidateSet<'a>>(
     candidate_sets: &'a [Set],
     query: &str,
@@ -157,7 +195,7 @@ pub async fn match_path_sets<'a, Set: PathMatchCandidateSet<'a>>(
                                     score,
                                     worktree_id,
                                     positions: Vec::new(),
-                                    path: candidate.path.clone(),
+                                    path: Arc::from(candidate.path),
                                     path_prefix: candidate_set.prefix(),
                                     distance_to_relative_ancestor: relative_to.as_ref().map_or(
                                         usize::MAX,

crates/gpui/Cargo.toml

@@ -11,7 +11,7 @@ path = "src/gpui.rs"
 doctest = false
 
 [features]
-test-support = ["backtrace", "dhat", "env_logger", "collections/test-support"]
+test-support = ["backtrace", "dhat", "env_logger", "collections/test-support", "util/test-support"]
 
 [dependencies]
 collections = { path = "../collections" }
@@ -53,7 +53,7 @@ thiserror.workspace = true
 time.workspace = true
 tiny-skia = "0.5"
 usvg = { version = "0.14", features = [] }
-uuid = { version = "1.1.2", features = ["v4"] }
+uuid.workspace = true
 waker-fn = "1.1.0"
 
 [build-dependencies]

crates/gpui/src/app.rs

@@ -1252,7 +1252,7 @@ impl AppContext {
                 result
             })
         } else {
-            panic!("circular model update");
+            panic!("circular model update for {}", std::any::type_name::<T>());
         }
     }
 

crates/gpui/src/app/window.rs

@@ -33,6 +33,7 @@ use std::{
     any::{type_name, Any, TypeId},
     mem,
     ops::{Deref, DerefMut, Range, Sub},
+    sync::Arc,
 };
 use taffy::{
     tree::{Measurable, MeasureFunc},
@@ -56,7 +57,7 @@ pub struct Window {
     pub(crate) rendered_views: HashMap<usize, Box<dyn AnyRootElement>>,
     scene: SceneBuilder,
     pub(crate) text_style_stack: Vec<TextStyle>,
-    pub(crate) theme_stack: Vec<Box<dyn Any>>,
+    pub(crate) theme_stack: Vec<Arc<dyn Any + Send + Sync>>,
     pub(crate) new_parents: HashMap<usize, usize>,
     pub(crate) views_to_notify_if_ancestors_change: HashMap<usize, SmallVec<[usize; 2]>>,
     titlebar_height: f32,
@@ -1336,18 +1337,21 @@ impl<'a> WindowContext<'a> {
         self.window.text_style_stack.pop();
     }
 
-    pub fn theme<T: 'static>(&self) -> &T {
+    pub fn theme<T: 'static + Send + Sync>(&self) -> Arc<T> {
         self.window
             .theme_stack
             .iter()
             .rev()
-            .find_map(|theme| theme.downcast_ref())
+            .find_map(|theme| {
+                let entry = Arc::clone(theme);
+                entry.downcast::<T>().ok()
+            })
             .ok_or_else(|| anyhow!("no theme provided of type {}", type_name::<T>()))
             .unwrap()
     }
 
-    pub fn push_theme<T: 'static>(&mut self, theme: T) {
-        self.window.theme_stack.push(Box::new(theme));
+    pub fn push_theme<T: 'static + Send + Sync>(&mut self, theme: T) {
+        self.window.theme_stack.push(Arc::new(theme));
     }
 
     pub fn pop_theme(&mut self) {

crates/gpui/src/font_cache.rs

@@ -98,7 +98,12 @@ impl FontCache {
         }
 
         Err(anyhow!(
-            "could not find a non-empty font family matching one of the given names"
+            "could not find a non-empty font family matching one of the given names: {}",
+            names
+                .iter()
+                .map(|name| format!("`{name}`"))
+                .collect::<Vec<_>>()
+                .join(", ")
         ))
     }
 

crates/gpui/src/geometry.rs

@@ -1,12 +1,12 @@
-use std::fmt::Debug;
-
 use super::scene::{Path, PathVertex};
 use crate::{color::Color, json::ToJson};
+use derive_more::Neg;
 pub use pathfinder_geometry::*;
 use rect::RectF;
 use refineable::Refineable;
 use serde::{Deserialize, Deserializer};
 use serde_json::json;
+use std::fmt::Debug;
 use vector::{vec2f, Vector2F};
 
 pub struct PathBuilder {
@@ -194,8 +194,8 @@ where
 impl Size<DefiniteLength> {
     pub fn zero() -> Self {
         Self {
-            width: pixels(0.),
-            height: pixels(0.),
+            width: pixels(0.).into(),
+            height: pixels(0.).into(),
         }
     }
 
@@ -235,6 +235,17 @@ pub struct Edges<T: Clone + Default + Debug> {
     pub left: T,
 }
 
+impl<T: Clone + Default + Debug> Edges<T> {
+    pub fn uniform(value: T) -> Self {
+        Self {
+            top: value.clone(),
+            right: value.clone(),
+            bottom: value.clone(),
+            left: value.clone(),
+        }
+    }
+}
+
 impl Edges<Length> {
     pub fn auto() -> Self {
         Self {
@@ -247,10 +258,10 @@ impl Edges<Length> {
 
     pub fn zero() -> Self {
         Self {
-            top: pixels(0.),
-            right: pixels(0.),
-            bottom: pixels(0.),
-            left: pixels(0.),
+            top: pixels(0.).into(),
+            right: pixels(0.).into(),
+            bottom: pixels(0.).into(),
+            left: pixels(0.).into(),
         }
     }
 
@@ -270,10 +281,10 @@ impl Edges<Length> {
 impl Edges<DefiniteLength> {
     pub fn zero() -> Self {
         Self {
-            top: pixels(0.),
-            right: pixels(0.),
-            bottom: pixels(0.),
-            left: pixels(0.),
+            top: pixels(0.).into(),
+            right: pixels(0.).into(),
+            bottom: pixels(0.).into(),
+            left: pixels(0.).into(),
         }
     }
 
@@ -322,7 +333,7 @@ impl Edges<f32> {
     }
 }
 
-#[derive(Clone, Copy)]
+#[derive(Clone, Copy, Neg)]
 pub enum AbsoluteLength {
     Pixels(f32),
     Rems(f32),
@@ -360,7 +371,7 @@ impl Default for AbsoluteLength {
 }
 
 /// A non-auto length that can be defined in pixels, rems, or percent of parent.
-#[derive(Clone, Copy)]
+#[derive(Clone, Copy, Neg)]
 pub enum DefiniteLength {
     Absolute(AbsoluteLength),
     Relative(f32), // 0. to 1.
@@ -404,7 +415,7 @@ impl Default for DefiniteLength {
 }
 
 /// A length that can be defined in pixels, rems, percent of parent, or auto.
-#[derive(Clone, Copy)]
+#[derive(Clone, Copy, Neg)]
 pub enum Length {
     Definite(DefiniteLength),
     Auto,
@@ -419,16 +430,16 @@ impl std::fmt::Debug for Length {
     }
 }
 
-pub fn relative<T: From<DefiniteLength>>(fraction: f32) -> T {
-    DefiniteLength::Relative(fraction).into()
+pub fn relative(fraction: f32) -> DefiniteLength {
+    DefiniteLength::Relative(fraction)
 }
 
-pub fn rems<T: From<AbsoluteLength>>(rems: f32) -> T {
-    AbsoluteLength::Rems(rems).into()
+pub fn rems(rems: f32) -> AbsoluteLength {
+    AbsoluteLength::Rems(rems)
 }
 
-pub fn pixels<T: From<AbsoluteLength>>(pixels: f32) -> T {
-    AbsoluteLength::Pixels(pixels).into()
+pub fn pixels(pixels: f32) -> AbsoluteLength {
+    AbsoluteLength::Pixels(pixels)
 }
 
 pub fn auto() -> Length {

crates/gpui/src/keymap_matcher/keystroke.rs

@@ -112,7 +112,7 @@ impl std::fmt::Display for Keystroke {
             f.write_char('^')?;
         }
         if self.alt {
-            f.write_char('⎇')?;
+            f.write_char('⌥')?;
         }
         if self.cmd {
             f.write_char('⌘')?;

crates/gpui/src/platform/test.rs

@@ -103,6 +103,7 @@ pub struct Platform {
     current_clipboard_item: Mutex<Option<ClipboardItem>>,
     cursor: Mutex<CursorStyle>,
     active_window: Arc<Mutex<Option<AnyWindowHandle>>>,
+    active_screen: Screen,
 }
 
 impl Platform {
@@ -113,6 +114,7 @@ impl Platform {
             current_clipboard_item: Default::default(),
             cursor: Mutex::new(CursorStyle::Arrow),
             active_window: Default::default(),
+            active_screen: Screen::new(),
         }
     }
 }
@@ -136,12 +138,16 @@ impl super::Platform for Platform {
 
     fn quit(&self) {}
 
-    fn screen_by_id(&self, _id: uuid::Uuid) -> Option<Rc<dyn crate::platform::Screen>> {
-        None
+    fn screen_by_id(&self, uuid: uuid::Uuid) -> Option<Rc<dyn crate::platform::Screen>> {
+        if self.active_screen.uuid == uuid {
+            Some(Rc::new(self.active_screen.clone()))
+        } else {
+            None
+        }
     }
 
     fn screens(&self) -> Vec<Rc<dyn crate::platform::Screen>> {
-        Default::default()
+        vec![Rc::new(self.active_screen.clone())]
     }
 
     fn open_window(
@@ -158,6 +164,7 @@ impl super::Platform for Platform {
                 WindowBounds::Fixed(rect) => rect.size(),
             },
             self.active_window.clone(),
+            Rc::new(self.active_screen.clone()),
         ))
     }
 
@@ -170,6 +177,7 @@ impl super::Platform for Platform {
             handle,
             vec2f(24., 24.),
             self.active_window.clone(),
+            Rc::new(self.active_screen.clone()),
         ))
     }
 
@@ -238,8 +246,18 @@ impl super::Platform for Platform {
     fn restart(&self) {}
 }
 
-#[derive(Debug)]
-pub struct Screen;
+#[derive(Debug, Clone)]
+pub struct Screen {
+    uuid: uuid::Uuid,
+}
+
+impl Screen {
+    fn new() -> Self {
+        Self {
+            uuid: uuid::Uuid::new_v4(),
+        }
+    }
+}
 
 impl super::Screen for Screen {
     fn as_any(&self) -> &dyn Any {
@@ -255,7 +273,7 @@ impl super::Screen for Screen {
     }
 
     fn display_uuid(&self) -> Option<uuid::Uuid> {
-        Some(uuid::Uuid::new_v4())
+        Some(self.uuid)
     }
 }
 
@@ -275,6 +293,7 @@ pub struct Window {
     pub(crate) edited: bool,
     pub(crate) pending_prompts: RefCell<VecDeque<oneshot::Sender<usize>>>,
     active_window: Arc<Mutex<Option<AnyWindowHandle>>>,
+    screen: Rc<Screen>,
 }
 
 impl Window {
@@ -282,6 +301,7 @@ impl Window {
         handle: AnyWindowHandle,
         size: Vector2F,
         active_window: Arc<Mutex<Option<AnyWindowHandle>>>,
+        screen: Rc<Screen>,
     ) -> Self {
         Self {
             handle,
@@ -299,6 +319,7 @@ impl Window {
             edited: false,
             pending_prompts: Default::default(),
             active_window,
+            screen,
         }
     }
 
@@ -329,7 +350,7 @@ impl super::Window for Window {
     }
 
     fn screen(&self) -> Rc<dyn crate::platform::Screen> {
-        Rc::new(Screen)
+        self.screen.clone()
     }
 
     fn mouse_position(&self) -> Vector2F {

crates/gpui/src/views/select.rs

@@ -53,8 +53,10 @@ impl Select {
     }
 
     pub fn set_item_count(&mut self, count: usize, cx: &mut ViewContext<Self>) {
-        self.item_count = count;
-        cx.notify();
+        if count != self.item_count {
+            self.item_count = count;
+            cx.notify();
+        }
     }
 
     fn toggle(&mut self, cx: &mut ViewContext<Self>) {
@@ -63,9 +65,11 @@ impl Select {
     }
 
     pub fn set_selected_index(&mut self, ix: usize, cx: &mut ViewContext<Self>) {
-        self.selected_item_ix = ix;
-        self.is_open = false;
-        cx.notify();
+        if ix != self.selected_item_ix || self.is_open {
+            self.selected_item_ix = ix;
+            self.is_open = false;
+            cx.notify();
+        }
     }
 
     pub fn selected_index(&self) -> usize {