From 0b81c19fa144303eee8c91a4e2ba075012321ed4 Mon Sep 17 00:00:00 2001
From: Conrad Irwin <conrad.irwin@gmail.com>
Date: Fri, 14 Mar 2025 12:41:11 -0600
Subject: [PATCH] vim: Add zH/zL/zh/zl

---
 assets/keymaps/vim.json         |  1 +
 crates/editor/src/element.rs    |  7 ++++++-
 crates/editor/src/scroll.rs     | 18 ++++++++++++++++++
 crates/vim/src/normal/scroll.rs | 31 ++++++++++++++++++++++++++++++-
 4 files changed, 55 insertions(+), 2 deletions(-)

diff --git a/assets/keymaps/vim.json b/assets/keymaps/vim.json
index fe0613eac3..dc77e77483 100644
--- a/assets/keymaps/vim.json
+++ b/assets/keymaps/vim.json
@@ -155,6 +155,7 @@
       "z +": ["workspace::SendKeystrokes", "shift-l j z t ^"],
       "z t": "editor::ScrollCursorTop",
       "z z": "editor::ScrollCursorCenter",
+      "z l": "vim::ScrollLeftHalfWay",
       "z .": ["workspace::SendKeystrokes", "z z ^"],
       "z b": "editor::ScrollCursorBottom",
       "z a": "editor::ToggleFold",
diff --git a/crates/editor/src/element.rs b/crates/editor/src/element.rs
index 812cf3c143..f0b648f160 100644
--- a/crates/editor/src/element.rs
+++ b/crates/editor/src/element.rs
@@ -15,7 +15,7 @@ use crate::{
     inlay_hint_settings,
     items::BufferSearchHighlights,
     mouse_context_menu::{self, MenuPosition, MouseContextMenu},
-    scroll::{axis_pair, scroll_amount::ScrollAmount, AxisPair},
+    scroll::{axis_pair, scroll_amount::ScrollAmount, AxisPair, HorizontalLayoutDetails},
     BlockId, ChunkReplacement, CursorShape, CustomBlockId, DisplayDiffHunk, DisplayPoint,
     DisplayRow, DocumentHighlightRead, DocumentHighlightWrite, EditDisplayMode, Editor, EditorMode,
     EditorSettings, EditorSnapshot, EditorStyle, FocusedBlock, GoToHunk, GoToPreviousHunk,
@@ -7031,6 +7031,11 @@ impl Element for EditorElement {
                     );
 
                     self.editor.update(cx, |editor, cx| {
+                        editor.scroll_manager.latest_horizontal_details = HorizontalLayoutDetails {
+                            letter_width: letter_size.width.0,
+                            editor_width: editor_width.0,
+                            scroll_max: scroll_max.x,
+                        };
                         let clamped = editor.scroll_manager.clamp_scroll_left(scroll_max.x);
 
                         let autoscrolled = if autoscroll_horizontally {
diff --git a/crates/editor/src/scroll.rs b/crates/editor/src/scroll.rs
index 0ba1fde0ab..8cefd7f6fc 100644
--- a/crates/editor/src/scroll.rs
+++ b/crates/editor/src/scroll.rs
@@ -172,6 +172,13 @@ impl OngoingScroll {
     }
 }
 
+#[derive(Default, Debug)]
+pub struct HorizontalLayoutDetails {
+    pub letter_width: f32,
+    pub editor_width: f32,
+    pub scroll_max: f32,
+}
+
 pub struct ScrollManager {
     pub(crate) vertical_scroll_margin: f32,
     anchor: ScrollAnchor,
@@ -183,6 +190,7 @@ pub struct ScrollManager {
     dragging_scrollbar: AxisPair<bool>,
     visible_line_count: Option<f32>,
     forbid_vertical_scroll: bool,
+    pub(crate) latest_horizontal_details: HorizontalLayoutDetails,
 }
 
 impl ScrollManager {
@@ -198,6 +206,7 @@ impl ScrollManager {
             last_autoscroll: None,
             visible_line_count: None,
             forbid_vertical_scroll: false,
+            latest_horizontal_details: Default::default(),
         }
     }
 
@@ -379,6 +388,15 @@ impl ScrollManager {
         cx.notify();
     }
 
+    pub fn horizontal_scroll(
+        &mut self,
+        f: impl Fn(f32, &HorizontalLayoutDetails) -> f32,
+        cx: &mut Context<Editor>,
+    ) {
+        self.anchor.offset.x = f(self.anchor.offset.x, &self.latest_horizontal_details);
+        cx.notify();
+    }
+
     pub fn clamp_scroll_left(&mut self, max: f32) -> bool {
         if max < self.anchor.offset.x {
             self.anchor.offset.x = max;
diff --git a/crates/vim/src/normal/scroll.rs b/crates/vim/src/normal/scroll.rs
index a7ae62741c..00f1db81c6 100644
--- a/crates/vim/src/normal/scroll.rs
+++ b/crates/vim/src/normal/scroll.rs
@@ -7,10 +7,20 @@ use editor::{
 use gpui::{actions, Context, Window};
 use language::Bias;
 use settings::Settings;
+use ui::px;
 
 actions!(
     vim,
-    [LineUp, LineDown, ScrollUp, ScrollDown, PageUp, PageDown]
+    [
+        LineUp,
+        LineDown,
+        ScrollUp,
+        ScrollDown,
+        PageUp,
+        PageDown,
+        ScrollLeftHalfWay,
+        ScrollRightHalfWay,
+    ]
 );
 
 pub fn register(editor: &mut Editor, cx: &mut Context<Vim>) {
@@ -44,6 +54,25 @@ pub fn register(editor: &mut Editor, cx: &mut Context<Vim>) {
             }
         })
     });
+
+    Vim::action(editor, cx, |vim, _: &ScrollLeftHalfWay, window, cx| {
+        dbg!("here!");
+        vim.update_editor(window, cx, |_, editor, window, cx| {
+            editor.scroll_manager.horizontal_scroll(
+                |current, details| (current + details.editor_width / 2.).min(details.scroll_max),
+                cx,
+            );
+        });
+    });
+    // Vim::action(editor, cx, |vim, _: &ScrollRightHalfWay, window, cx| {
+    //     vim.scroll_horizontal(window, cx, |c| {
+    //         if let Some(c) = c {
+    //             ScrollAmount::Line(-c)
+    //         } else {
+    //             ScrollAmount::Page(-0.5)
+    //         }
+    //     })
+    // });
 }
 
 impl Vim {