WIP: start using replace blocks for patches

Otherwise it becomes impossible to address certain ranges in the buffer.

crates/assistant/src/assistant_panel.rs

@@ -26,8 +26,8 @@ use collections::{BTreeSet, HashMap, HashSet};
 use editor::{
     actions::{FoldAt, MoveToEndOfLine, Newline, ShowCompletions, UnfoldAt},
     display_map::{
-        BlockContext, BlockDisposition, BlockId, BlockProperties, BlockStyle, Crease,
-        CreaseMetadata, CustomBlockId, FoldId, RenderBlock, ToDisplayPoint,
+        BlockContext, BlockId, BlockPlacement, BlockProperties, BlockStyle, Crease, CreaseMetadata,
+        CustomBlockId, FoldId, RenderBlock, ToDisplayPoint,
     },
     scroll::{Autoscroll, AutoscrollStrategy},
     Anchor, Editor, EditorEvent, ProposedChangeLocation, ProposedChangesEditor, RowExt,
@@ -1446,8 +1446,8 @@ struct ScrollPosition {
 }
 
 struct PatchViewState {
-    footer_block_id: CustomBlockId,
-    crease_id: CreaseId,
+    block_id: CustomBlockId,
+    // crease_id: CreaseId,
     editor: Option<PatchEditorState>,
     update_task: Option<Task<()>>,
 }
@@ -2009,13 +2009,12 @@ impl ContextEditor {
                             })
                             .map(|(command, error_message)| BlockProperties {
                                 style: BlockStyle::Fixed,
-                                position: Anchor {
+                                height: 1,
+                                placement: BlockPlacement::Below(Anchor {
                                     buffer_id: Some(buffer_id),
                                     excerpt_id,
                                     text_anchor: command.source_range.start,
-                                },
-                                height: 1,
-                                disposition: BlockDisposition::Below,
+                                }),
                                 render: slash_command_error_block_renderer(error_message),
                                 priority: 0,
                             }),
@@ -2159,8 +2158,8 @@ impl ContextEditor {
         for range in removed {
             if let Some(state) = self.patches.remove(range) {
                 editors_to_close.extend(state.editor.and_then(|state| state.editor.upgrade()));
-                removed_block_ids.insert(state.footer_block_id);
-                removed_crease_ids.push(state.crease_id);
+                removed_block_ids.insert(state.block_id);
+                // removed_crease_ids.push(state.crease_id);
             }
         }
 
@@ -2190,7 +2189,7 @@ impl ContextEditor {
                         let gutter_width = cx.gutter_dimensions.full_width();
                         let block_id = cx.block_id;
                         this.update(&mut **cx, |this, cx| {
-                            this.render_patch_footer(
+                            this.render_patch(
                                 patch_range.clone(),
                                 max_width,
                                 gutter_width,
@@ -2204,26 +2203,9 @@ impl ContextEditor {
                     }
                 });
 
-                let header_placeholder = FoldPlaceholder {
-                    render: {
-                        let this = this.clone();
-                        let patch_range = range.clone();
-                        Arc::new(move |fold_id, _range, cx| {
-                            this.update(cx, |this, cx| {
-                                this.render_patch_header(patch_range.clone(), fold_id, cx)
-                            })
-                            .ok()
-                            .flatten()
-                            .unwrap_or_else(|| Empty.into_any())
-                        })
-                    },
-                    constrain_width: false,
-                    merge_adjacent: false,
-                };
-
                 let should_refold;
                 if let Some(state) = self.patches.get_mut(&range) {
-                    replaced_blocks.insert(state.footer_block_id, render_block);
+                    replaced_blocks.insert(state.block_id, render_block);
                     if let Some(editor_state) = &state.editor {
                         if editor_state.opened_patch != patch {
                             state.update_task = Some({
@@ -2242,32 +2224,31 @@ impl ContextEditor {
                 } else {
                     let block_ids = editor.insert_blocks(
                         [BlockProperties {
-                            position: patch_start,
                             height: path_count as u32 + 1,
-                            style: BlockStyle::Flex,
+                            style: BlockStyle::Fixed,
                             render: render_block,
-                            disposition: BlockDisposition::Below,
+                            placement: BlockPlacement::Replace(patch_start..patch_end),
                             priority: 0,
                         }],
                         None,
                         cx,
                     );
 
-                    let new_crease_ids = editor.insert_creases(
-                        [Crease::new(
-                            patch_start..patch_end,
-                            header_placeholder.clone(),
-                            fold_toggle("patch-header"),
-                            |_, _, _| Empty.into_any_element(),
-                        )],
-                        cx,
-                    );
+                    // let new_crease_ids = editor.insert_creases(
+                    //     [Crease::new(
+                    //         patch_start..patch_end,
+                    //         header_placeholder.clone(),
+                    //         fold_toggle("patch-header"),
+                    //         |_, _, _| Empty.into_any_element(),
+                    //     )],
+                    //     cx,
+                    // );
 
                     self.patches.insert(
                         range.clone(),
                         PatchViewState {
-                            footer_block_id: block_ids[0],
-                            crease_id: new_crease_ids[0],
+                            block_id: block_ids[0],
+                            // crease_id: new_crease_ids[0],
                             editor: None,
                             update_task: None,
                         },
@@ -2277,8 +2258,8 @@ impl ContextEditor {
                 }
 
                 if should_refold {
-                    editor.unfold_ranges([patch_start..patch_end], true, false, cx);
-                    editor.fold_ranges([(patch_start..patch_end, header_placeholder)], false, cx);
+                    // editor.unfold_ranges([patch_start..patch_end], true, false, cx);
+                    // editor.fold_ranges([(patch_start..patch_end, header_placeholder)], false, cx);
                 }
             }
 
@@ -2731,12 +2712,13 @@ impl ContextEditor {
                 })
             };
             let create_block_properties = |message: &Message| BlockProperties {
-                position: buffer
-                    .anchor_in_excerpt(excerpt_id, message.anchor_range.start)
-                    .unwrap(),
                 height: 2,
                 style: BlockStyle::Sticky,
-                disposition: BlockDisposition::Above,
+                placement: BlockPlacement::Above(
+                    buffer
+                        .anchor_in_excerpt(excerpt_id, message.anchor_range.start)
+                        .unwrap(),
+                ),
                 priority: usize::MAX,
                 render: render_block(MessageMetadata::from(message)),
             };
@@ -3372,7 +3354,7 @@ impl ContextEditor {
                     let anchor = buffer.anchor_in_excerpt(excerpt_id, anchor).unwrap();
                     let image = render_image.clone();
                     anchor.is_valid(&buffer).then(|| BlockProperties {
-                        position: anchor,
+                        placement: BlockPlacement::Above(anchor),
                         height: MAX_HEIGHT_IN_LINES,
                         style: BlockStyle::Sticky,
                         render: Box::new(move |cx| {
@@ -3393,8 +3375,6 @@ impl ContextEditor {
                                 )
                                 .into_any_element()
                         }),
-
-                        disposition: BlockDisposition::Above,
                         priority: 0,
                     })
                 })
@@ -3434,28 +3414,7 @@ impl ContextEditor {
             .unwrap_or_else(|| Cow::Borrowed(DEFAULT_TAB_TITLE))
     }
 
-    fn render_patch_header(
-        &self,
-        range: Range<text::Anchor>,
-        _id: FoldId,
-        cx: &mut ViewContext<Self>,
-    ) -> Option<AnyElement> {
-        let patch = self.context.read(cx).patch_for_range(&range, cx)?;
-        let theme = cx.theme().clone();
-        Some(
-            h_flex()
-                .px_1()
-                .py_0p5()
-                .border_b_1()
-                .border_color(theme.status().info_border)
-                .gap_1()
-                .child(Icon::new(IconName::Diff).size(IconSize::Small))
-                .child(Label::new(patch.title.clone()).size(LabelSize::Small))
-                .into_any(),
-        )
-    }
-
-    fn render_patch_footer(
+    fn render_patch(
         &mut self,
         range: Range<text::Anchor>,
         max_width: Pixels,
@@ -3471,10 +3430,6 @@ impl ContextEditor {
             .anchor_in_excerpt(excerpt_id, range.start)
             .unwrap();
 
-        if !snapshot.intersects_fold(anchor) {
-            return None;
-        }
-
         let patch = self.context.read(cx).patch_for_range(&range, cx)?;
         let paths = patch
             .paths()
@@ -3483,10 +3438,13 @@ impl ContextEditor {
 
         Some(
             v_flex()
+                .border_1()
+                .border_color(cx.theme().colors().border)
                 .id(id)
-                .pl(gutter_width)
-                .w(max_width)
-                .py_2()
+                .ml(gutter_width)
+                .p_2()
+                .rounded_md()
+                .min_h(cx.line_height() * 3.)
                 .cursor(CursorStyle::PointingHand)
                 .on_click(cx.listener(move |this, _, cx| {
                     this.editor.update(cx, |editor, cx| {
@@ -3496,6 +3454,7 @@ impl ContextEditor {
                     });
                     this.focus_active_patch(cx);
                 }))
+                .child(Label::new(patch.title.clone()))
                 .children(paths.into_iter().map(|path| {
                     h_flex()
                         .pl_1()

crates/assistant/src/inline_assistant.rs

@@ -9,7 +9,7 @@ use collections::{hash_map, HashMap, HashSet, VecDeque};
 use editor::{
     actions::{MoveDown, MoveUp, SelectAll},
     display_map::{
-        BlockContext, BlockDisposition, BlockProperties, BlockStyle, CustomBlockId, RenderBlock,
+        BlockContext, BlockPlacement, BlockProperties, BlockStyle, CustomBlockId, RenderBlock,
         ToDisplayPoint,
     },
     Anchor, AnchorRangeExt, CodeActionProvider, Editor, EditorElement, EditorEvent, EditorMode,
@@ -446,15 +446,14 @@ impl InlineAssistant {
         let assist_blocks = vec![
             BlockProperties {
                 style: BlockStyle::Sticky,
-                position: range.start,
+                placement: BlockPlacement::Above(range.start),
                 height: prompt_editor_height,
                 render: build_assist_editor_renderer(prompt_editor),
-                disposition: BlockDisposition::Above,
                 priority: 0,
             },
             BlockProperties {
                 style: BlockStyle::Sticky,
-                position: range.end,
+                placement: BlockPlacement::Below(range.end),
                 height: 0,
                 render: Box::new(|cx| {
                     v_flex()
@@ -464,7 +463,6 @@ impl InlineAssistant {
                         .border_color(cx.theme().status().info_border)
                         .into_any_element()
                 }),
-                disposition: BlockDisposition::Below,
                 priority: 0,
             },
         ];
@@ -1179,7 +1177,7 @@ impl InlineAssistant {
                 let height =
                     deleted_lines_editor.update(cx, |editor, cx| editor.max_point(cx).row().0 + 1);
                 new_blocks.push(BlockProperties {
-                    position: new_row,
+                    placement: BlockPlacement::Above(new_row),
                     height,
                     style: BlockStyle::Flex,
                     render: Box::new(move |cx| {
@@ -1191,7 +1189,6 @@ impl InlineAssistant {
                             .child(deleted_lines_editor.clone())
                             .into_any_element()
                     }),
-                    disposition: BlockDisposition::Above,
                     priority: 0,
                 });
             }

crates/diagnostics/src/diagnostics.rs

@@ -9,7 +9,7 @@ use anyhow::Result;
 use collections::{BTreeSet, HashSet};
 use editor::{
     diagnostic_block_renderer,
-    display_map::{BlockDisposition, BlockProperties, BlockStyle, CustomBlockId, RenderBlock},
+    display_map::{BlockPlacement, BlockProperties, BlockStyle, CustomBlockId, RenderBlock},
     highlight_diagnostic_message,
     scroll::Autoscroll,
     Editor, EditorEvent, ExcerptId, ExcerptRange, MultiBuffer, ToOffset,
@@ -439,11 +439,10 @@ impl ProjectDiagnosticsEditor {
                                     primary.message.split('\n').next().unwrap().to_string();
                                 group_state.block_count += 1;
                                 blocks_to_add.push(BlockProperties {
-                                    position: header_position,
+                                    placement: BlockPlacement::Above(header_position),
                                     height: 2,
                                     style: BlockStyle::Sticky,
                                     render: diagnostic_header_renderer(primary),
-                                    disposition: BlockDisposition::Above,
                                     priority: 0,
                                 });
                             }
@@ -459,13 +458,15 @@ impl ProjectDiagnosticsEditor {
                                 if !diagnostic.message.is_empty() {
                                     group_state.block_count += 1;
                                     blocks_to_add.push(BlockProperties {
-                                        position: (excerpt_id, entry.range.start),
+                                        placement: BlockPlacement::Below((
+                                            excerpt_id,
+                                            entry.range.start,
+                                        )),
                                         height: diagnostic.message.matches('\n').count() as u32 + 1,
                                         style: BlockStyle::Fixed,
                                         render: diagnostic_block_renderer(
                                             diagnostic, None, true, true,
                                         ),
-                                        disposition: BlockDisposition::Below,
                                         priority: 0,
                                     });
                                 }
@@ -498,13 +499,24 @@ impl ProjectDiagnosticsEditor {
             editor.remove_blocks(blocks_to_remove, None, cx);
             let block_ids = editor.insert_blocks(
                 blocks_to_add.into_iter().flat_map(|block| {
-                    let (excerpt_id, text_anchor) = block.position;
+                    let placement = match block.placement {
+                        BlockPlacement::Above((excerpt_id, text_anchor)) => BlockPlacement::Above(
+                            excerpts_snapshot.anchor_in_excerpt(excerpt_id, text_anchor)?,
+                        ),
+                        BlockPlacement::Below((excerpt_id, text_anchor)) => BlockPlacement::Below(
+                            excerpts_snapshot.anchor_in_excerpt(excerpt_id, text_anchor)?,
+                        ),
+                        BlockPlacement::Replace(_) => {
+                            unreachable!(
+                                "no Replace block should have been pushed to blocks_to_add"
+                            )
+                        }
+                    };
                     Some(BlockProperties {
-                        position: excerpts_snapshot.anchor_in_excerpt(excerpt_id, text_anchor)?,
+                        placement,
                         height: block.height,
                         style: block.style,
                         render: block.render,
-                        disposition: block.disposition,
                         priority: 0,
                     })
                 }),

crates/editor/src/display_map.rs

@@ -29,8 +29,8 @@ use crate::{
     hover_links::InlayHighlight, movement::TextLayoutDetails, EditorStyle, InlayId, RowExt,
 };
 pub use block_map::{
-    Block, BlockBufferRows, BlockChunks as DisplayChunks, BlockContext, BlockDisposition, BlockId,
-    BlockMap, BlockPoint, BlockProperties, BlockStyle, CustomBlockId, RenderBlock,
+    Block, BlockBufferRows, BlockChunks as DisplayChunks, BlockContext, BlockId, BlockMap,
+    BlockPlacement, BlockPoint, BlockProperties, BlockStyle, CustomBlockId, RenderBlock,
 };
 use block_map::{BlockRow, BlockSnapshot};
 use char_map::{CharMap, CharSnapshot};
@@ -1180,6 +1180,7 @@ impl ToDisplayPoint for Anchor {
 pub mod tests {
     use super::*;
     use crate::{movement, test::marked_display_snapshot};
+    use block_map::BlockPlacement;
     use gpui::{div, font, observe, px, AppContext, BorrowAppContext, Context, Element, Hsla};
     use language::{
         language_settings::{AllLanguageSettings, AllLanguageSettingsContent},
@@ -1293,24 +1294,22 @@ pub mod tests {
                                             Bias::Left,
                                         ));
 
-                                    let disposition = if rng.gen() {
-                                        BlockDisposition::Above
+                                    let placement = if rng.gen() {
+                                        BlockPlacement::Above(position)
                                     } else {
-                                        BlockDisposition::Below
+                                        BlockPlacement::Below(position)
                                     };
                                     let height = rng.gen_range(1..5);
                                     log::info!(
-                                        "inserting block {:?} {:?} with height {}",
-                                        disposition,
-                                        position.to_point(&buffer),
+                                        "inserting block {:?} with height {}",
+                                        placement.as_ref().map(|p| p.to_point(&buffer)),
                                         height
                                     );
                                     let priority = rng.gen_range(1..100);
                                     BlockProperties {
+                                        placement,
                                         style: BlockStyle::Fixed,
-                                        position,
                                         height,
-                                        disposition,
                                         render: Box::new(|_| div().into_any()),
                                         priority,
                                     }

crates/editor/src/display_map/char_map.rs

@@ -252,6 +252,7 @@ impl CharSnapshot {
         };
 
         TabChunks {
+            snapshot: self,
             fold_chunks: self.fold_snapshot.chunks(
                 input_start..input_end,
                 language_aware,
@@ -492,6 +493,7 @@ impl<'a> std::ops::AddAssign<&'a Self> for TextSummary {
 const SPACES: &str = "                ";
 
 pub struct TabChunks<'a> {
+    snapshot: &'a CharSnapshot,
     fold_chunks: FoldChunks<'a>,
     chunk: Chunk<'a>,
     column: u32,
@@ -503,6 +505,37 @@ pub struct TabChunks<'a> {
     inside_leading_tab: bool,
 }
 
+impl<'a> TabChunks<'a> {
+    pub(crate) fn seek(&mut self, range: Range<CharPoint>) {
+        let (input_start, expanded_char_column, to_next_stop) =
+            self.snapshot.to_fold_point(range.start, Bias::Left);
+        let input_column = input_start.column();
+        let input_start = input_start.to_offset(&self.snapshot.fold_snapshot);
+        let input_end = self
+            .snapshot
+            .to_fold_point(range.end, Bias::Right)
+            .0
+            .to_offset(&self.snapshot.fold_snapshot);
+        let to_next_stop = if range.start.0 + Point::new(0, to_next_stop) > range.end.0 {
+            range.end.column() - range.start.column()
+        } else {
+            to_next_stop
+        };
+
+        self.fold_chunks.seek(input_start..input_end);
+        self.input_column = input_column;
+        self.column = expanded_char_column;
+        self.output_position = range.start.0;
+        self.max_output_position = range.end.0;
+        self.chunk = Chunk {
+            text: &SPACES[0..(to_next_stop as usize)],
+            is_tab: true,
+            ..Default::default()
+        };
+        self.inside_leading_tab = to_next_stop > 0;
+    }
+}
+
 impl<'a> Iterator for TabChunks<'a> {
     type Item = Chunk<'a>;
 

crates/editor/src/display_map/fold_map.rs

@@ -1100,6 +1100,17 @@ pub struct FoldBufferRows<'a> {
     fold_point: FoldPoint,
 }
 
+impl<'a> FoldBufferRows<'a> {
+    pub(crate) fn seek(&mut self, row: u32) {
+        let fold_point = FoldPoint::new(row, 0);
+        self.cursor.seek(&fold_point, Bias::Left, &());
+        let overshoot = fold_point.0 - self.cursor.start().0 .0;
+        let inlay_point = InlayPoint(self.cursor.start().1 .0 + overshoot);
+        self.input_buffer_rows.seek(inlay_point.row());
+        self.fold_point = fold_point;
+    }
+}
+
 impl<'a> Iterator for FoldBufferRows<'a> {
     type Item = Option<u32>;
 
@@ -1135,6 +1146,38 @@ pub struct FoldChunks<'a> {
     max_output_offset: FoldOffset,
 }
 
+impl<'a> FoldChunks<'a> {
+    pub(crate) fn seek(&mut self, range: Range<FoldOffset>) {
+        self.transform_cursor.seek(&range.start, Bias::Right, &());
+
+        let inlay_start = {
+            let overshoot = range.start.0 - self.transform_cursor.start().0 .0;
+            self.transform_cursor.start().1 + InlayOffset(overshoot)
+        };
+
+        let transform_end = self.transform_cursor.end(&());
+
+        let inlay_end = if self
+            .transform_cursor
+            .item()
+            .map_or(true, |transform| transform.is_fold())
+        {
+            inlay_start
+        } else if range.end < transform_end.0 {
+            let overshoot = range.end.0 - self.transform_cursor.start().0 .0;
+            self.transform_cursor.start().1 + InlayOffset(overshoot)
+        } else {
+            transform_end.1
+        };
+
+        self.inlay_chunks.seek(inlay_start..inlay_end);
+        self.inlay_chunk = None;
+        self.inlay_offset = inlay_start;
+        self.output_offset = range.start;
+        self.max_output_offset = range.end;
+    }
+}
+
 impl<'a> Iterator for FoldChunks<'a> {
     type Item = Chunk<'a>;
 

crates/editor/src/display_map/wrap_map.rs

@@ -56,6 +56,7 @@ pub struct WrapChunks<'a> {
     output_position: WrapPoint,
     max_output_row: u32,
     transforms: Cursor<'a, Transform, (WrapPoint, CharPoint)>,
+    snapshot: &'a WrapSnapshot,
 }
 
 #[derive(Clone)]
@@ -68,6 +69,21 @@ pub struct WrapBufferRows<'a> {
     transforms: Cursor<'a, Transform, (WrapPoint, CharPoint)>,
 }
 
+impl<'a> WrapBufferRows<'a> {
+    pub(crate) fn seek(&mut self, start_row: u32) {
+        self.transforms
+            .seek(&WrapPoint::new(start_row, 0), Bias::Left, &());
+        let mut input_row = self.transforms.start().1.row();
+        if self.transforms.item().map_or(false, |t| t.is_isomorphic()) {
+            input_row += start_row - self.transforms.start().0.row();
+        }
+        self.soft_wrapped = self.transforms.item().map_or(false, |t| !t.is_isomorphic());
+        self.input_buffer_rows.seek(input_row);
+        self.input_buffer_row = self.input_buffer_rows.next().unwrap();
+        self.output_row = start_row;
+    }
+}
+
 impl WrapMap {
     pub fn new(
         char_snapshot: CharSnapshot,
@@ -602,6 +618,7 @@ impl WrapSnapshot {
             output_position: output_start,
             max_output_row: rows.end,
             transforms,
+            snapshot: self,
         }
     }
 
@@ -629,6 +646,67 @@ impl WrapSnapshot {
         }
     }
 
+    pub fn text_summary_for_range(&self, rows: Range<u32>) -> TextSummary {
+        let mut summary = TextSummary::default();
+
+        let start = WrapPoint::new(rows.start, 0);
+        let end = WrapPoint::new(rows.end, 0);
+
+        let mut cursor = self.transforms.cursor::<(WrapPoint, CharPoint)>(&());
+        cursor.seek(&start, Bias::Right, &());
+        if let Some(transform) = cursor.item() {
+            let start_in_transform = start.0 - cursor.start().0 .0;
+            let end_in_transform = cmp::min(end, cursor.end(&()).0).0 - cursor.start().0 .0;
+            if transform.is_isomorphic() {
+                let char_start = CharPoint(cursor.start().1 .0 + start_in_transform);
+                let char_end = CharPoint(cursor.start().1 .0 + end_in_transform);
+                summary += &self
+                    .char_snapshot
+                    .text_summary_for_range(char_start..char_end);
+            } else {
+                debug_assert_eq!(start_in_transform.row, end_in_transform.row);
+                let indent_len = end_in_transform.column - start_in_transform.column;
+                summary += &TextSummary {
+                    lines: Point::new(0, indent_len),
+                    first_line_chars: indent_len,
+                    last_line_chars: indent_len,
+                    longest_row: 0,
+                    longest_row_chars: indent_len,
+                };
+            }
+
+            cursor.next(&());
+        }
+
+        if rows.end > cursor.start().0.row() {
+            summary += &cursor
+                .summary::<_, TransformSummary>(&WrapPoint::new(rows.end, 0), Bias::Right, &())
+                .output;
+
+            if let Some(transform) = cursor.item() {
+                let end_in_transform = end.0 - cursor.start().0 .0;
+                if transform.is_isomorphic() {
+                    let char_start = cursor.start().1;
+                    let char_end = CharPoint(char_start.0 + end_in_transform);
+                    summary += &self
+                        .char_snapshot
+                        .text_summary_for_range(char_start..char_end);
+                } else {
+                    debug_assert_eq!(end_in_transform, Point::new(1, 0));
+                    summary += &TextSummary {
+                        lines: Point::new(1, 0),
+                        first_line_chars: 0,
+                        last_line_chars: 0,
+                        longest_row: 0,
+                        longest_row_chars: 0,
+                    };
+                }
+            }
+        }
+
+        summary
+    }
+
     pub fn soft_wrap_indent(&self, row: u32) -> Option<u32> {
         let mut cursor = self.transforms.cursor::<WrapPoint>(&());
         cursor.seek(&WrapPoint::new(row + 1, 0), Bias::Right, &());
@@ -745,6 +823,21 @@ impl WrapSnapshot {
         None
     }
 
+    #[cfg(test)]
+    pub fn text(&self) -> String {
+        self.text_chunks(0).collect()
+    }
+
+    #[cfg(test)]
+    pub fn text_chunks(&self, wrap_row: u32) -> impl Iterator<Item = &str> {
+        self.chunks(
+            wrap_row..self.max_point().row() + 1,
+            false,
+            Highlights::default(),
+        )
+        .map(|h| h.text)
+    }
+
     fn check_invariants(&self) {
         #[cfg(test)]
         {
@@ -791,6 +884,26 @@ impl WrapSnapshot {
     }
 }
 
+impl<'a> WrapChunks<'a> {
+    pub(crate) fn seek(&mut self, rows: Range<u32>) {
+        let output_start = WrapPoint::new(rows.start, 0);
+        let output_end = WrapPoint::new(rows.end, 0);
+        self.transforms.seek(&output_start, Bias::Right, &());
+        let mut input_start = CharPoint(self.transforms.start().1 .0);
+        if self.transforms.item().map_or(false, |t| t.is_isomorphic()) {
+            input_start.0 += output_start.0 - self.transforms.start().0 .0;
+        }
+        let input_end = self
+            .snapshot
+            .to_char_point(output_end)
+            .min(self.snapshot.char_snapshot.max_point());
+        self.input_chunks.seek(input_start..input_end);
+        self.input_chunk = Chunk::default();
+        self.output_position = output_start;
+        self.max_output_row = rows.end;
+    }
+}
+
 impl<'a> Iterator for WrapChunks<'a> {
     type Item = Chunk<'a>;
 
@@ -1336,19 +1449,6 @@ mod tests {
     }
 
     impl WrapSnapshot {
-        pub fn text(&self) -> String {
-            self.text_chunks(0).collect()
-        }
-
-        pub fn text_chunks(&self, wrap_row: u32) -> impl Iterator<Item = &str> {
-            self.chunks(
-                wrap_row..self.max_point().row() + 1,
-                false,
-                Highlights::default(),
-            )
-            .map(|h| h.text)
-        }
-
         fn verify_chunks(&mut self, rng: &mut impl Rng) {
             for _ in 0..5 {
                 let mut end_row = rng.gen_range(0..=self.max_point().row());

crates/editor/src/editor.rs

@@ -10210,7 +10210,7 @@ impl Editor {
                     let block_id = this.insert_blocks(
                         [BlockProperties {
                             style: BlockStyle::Flex,
-                            position: range.start,
+                            placement: BlockPlacement::Below(range.start),
                             height: 1,
                             render: Box::new({
                                 let rename_editor = rename_editor.clone();
@@ -10246,7 +10246,6 @@ impl Editor {
                                         .into_any_element()
                                 }
                             }),
-                            disposition: BlockDisposition::Below,
                             priority: 0,
                         }],
                         Some(Autoscroll::fit()),
@@ -10531,10 +10530,11 @@ impl Editor {
                         let message_height = diagnostic.message.matches('\n').count() as u32 + 1;
                         BlockProperties {
                             style: BlockStyle::Fixed,
-                            position: buffer.anchor_after(entry.range.start),
+                            placement: BlockPlacement::Below(
+                                buffer.anchor_after(entry.range.start),
+                            ),
                             height: message_height,
                             render: diagnostic_block_renderer(diagnostic, None, true, true),
-                            disposition: BlockDisposition::Below,
                             priority: 0,
                         }
                     }),

crates/editor/src/editor_tests.rs

@@ -3868,8 +3868,7 @@ fn test_move_line_up_down_with_blocks(cx: &mut TestAppContext) {
         editor.insert_blocks(
             [BlockProperties {
                 style: BlockStyle::Fixed,
-                position: snapshot.anchor_after(Point::new(2, 0)),
-                disposition: BlockDisposition::Below,
+                placement: BlockPlacement::Below(snapshot.anchor_after(Point::new(2, 0))),
                 height: 1,
                 render: Box::new(|_| div().into_any()),
                 priority: 0,

crates/editor/src/element.rs

@@ -2071,7 +2071,7 @@ impl EditorElement {
         let mut element = match block {
             Block::Custom(block) => {
                 let align_to = block
-                    .position()
+                    .start()
                     .to_point(&snapshot.buffer_snapshot)
                     .to_display_point(snapshot);
                 let anchor_x = text_x
@@ -6294,7 +6294,7 @@ fn compute_auto_height_layout(
 mod tests {
     use super::*;
     use crate::{
-        display_map::{BlockDisposition, BlockProperties},
+        display_map::{BlockPlacement, BlockProperties},
         editor_tests::{init_test, update_test_language_settings},
         Editor, MultiBuffer,
     };
@@ -6550,9 +6550,8 @@ mod tests {
                 editor.insert_blocks(
                     [BlockProperties {
                         style: BlockStyle::Fixed,
-                        disposition: BlockDisposition::Above,
+                        placement: BlockPlacement::Above(Anchor::min()),
                         height: 3,
-                        position: Anchor::min(),
                         render: Box::new(|cx| div().h(3. * cx.line_height()).into_any()),
                         priority: 0,
                     }],

crates/editor/src/hunk_diff.rs

@@ -17,7 +17,7 @@ use workspace::Item;
 
 use crate::{
     editor_settings::CurrentLineHighlight, hunk_status, hunks_for_selections, ApplyDiffHunk,
-    BlockDisposition, BlockProperties, BlockStyle, CustomBlockId, DiffRowHighlight, DisplayRow,
+    BlockPlacement, BlockProperties, BlockStyle, CustomBlockId, DiffRowHighlight, DisplayRow,
     DisplaySnapshot, Editor, EditorElement, ExpandAllHunkDiffs, GoToHunk, GoToPrevHunk, RevertFile,
     RevertSelectedHunks, ToDisplayPoint, ToggleHunkDiff,
 };
@@ -417,10 +417,9 @@ impl Editor {
         };
 
         BlockProperties {
-            position: hunk.multi_buffer_range.start,
+            placement: BlockPlacement::Above(hunk.multi_buffer_range.start),
             height: 1,
             style: BlockStyle::Sticky,
-            disposition: BlockDisposition::Above,
             priority: 0,
             render: Box::new({
                 let editor = cx.view().clone();
@@ -700,10 +699,9 @@ impl Editor {
         let hunk = hunk.clone();
         let height = editor_height.max(deleted_text_height);
         BlockProperties {
-            position: hunk.multi_buffer_range.start,
+            placement: BlockPlacement::Above(hunk.multi_buffer_range.start),
             height,
             style: BlockStyle::Flex,
-            disposition: BlockDisposition::Above,
             priority: 0,
             render: Box::new(move |cx| {
                 let width = EditorElement::diff_hunk_strip_width(cx.line_height());

crates/repl/src/session.rs

@@ -8,7 +8,7 @@ use client::telemetry::Telemetry;
 use collections::{HashMap, HashSet};
 use editor::{
     display_map::{
-        BlockContext, BlockDisposition, BlockId, BlockProperties, BlockStyle, CustomBlockId,
+        BlockContext, BlockId, BlockPlacement, BlockProperties, BlockStyle, CustomBlockId,
         RenderBlock,
     },
     scroll::Autoscroll,
@@ -90,12 +90,11 @@ impl EditorBlock {
 
             let invalidation_anchor = buffer.read(cx).read(cx).anchor_before(next_row_start);
             let block = BlockProperties {
-                position: code_range.end,
+                placement: BlockPlacement::Below(code_range.end),
                 // Take up at least one height for status, allow the editor to determine the real height based on the content from render
                 height: 1,
                 style: BlockStyle::Sticky,
                 render: Self::create_output_area_renderer(execution_view.clone(), on_close.clone()),
-                disposition: BlockDisposition::Below,
                 priority: 0,
             };