Add excerpts into outline panel (#13034)

Follow-up of https://github.com/zed-industries/zed/pull/12637

Adds excerpt items into the outline panel: now all outline items are
initially hidden under excerpt items that could be toggled open/closed
similar to directories.


![Screenshot 2024-06-14 at 10 45
04](https://github.com/zed-industries/zed/assets/2690773/9c9ef91b-1666-43c3-acc4-96f850098a28)

On active editor's selection change, a corresponding outline will be
revealed still, expanding the corresponding excerpt

![Screenshot 2024-06-14 at 10 45
13](https://github.com/zed-industries/zed/assets/2690773/7dfd14f7-4aca-48f2-8760-8e1362b9a043)

Release Notes:

- N/A

Cargo.lock

@@ -7160,8 +7160,9 @@ dependencies = [
  "db",
  "editor",
  "file_icons",
- "git",
+ "futures 0.3.28",
  "gpui",
+ "itertools 0.11.0",
  "language",
  "log",
  "menu",

crates/collab_ui/src/channel_view.rs

@@ -228,7 +228,7 @@ impl ChannelView {
             &self.editor,
             move |this, _, e: &EditorEvent, cx| {
                 match e {
-                    EditorEvent::Reparsed => {
+                    EditorEvent::Reparsed(_) => {
                         this.focus_position_from_link(position.clone(), false, cx);
                         this._reparse_subscription.take();
                     }

crates/editor/src/editor.rs

@@ -10888,14 +10888,14 @@ impl Editor {
             multi_buffer::Event::ExcerptsExpanded { ids } => {
                 cx.emit(EditorEvent::ExcerptsExpanded { ids: ids.clone() })
             }
-            multi_buffer::Event::Reparsed => {
+            multi_buffer::Event::Reparsed(buffer_id) => {
                 self.tasks_update_task = Some(self.refresh_runnables(cx));
 
-                cx.emit(EditorEvent::Reparsed);
+                cx.emit(EditorEvent::Reparsed(*buffer_id));
             }
-            multi_buffer::Event::LanguageChanged => {
+            multi_buffer::Event::LanguageChanged(buffer_id) => {
                 linked_editing_ranges::refresh_linked_ranges(self, cx);
-                cx.emit(EditorEvent::Reparsed);
+                cx.emit(EditorEvent::Reparsed(*buffer_id));
                 cx.notify();
             }
             multi_buffer::Event::DirtyChanged => cx.emit(EditorEvent::DirtyChanged),
@@ -11818,7 +11818,7 @@ pub enum EditorEvent {
     Edited {
         transaction_id: clock::Lamport,
     },
-    Reparsed,
+    Reparsed(BufferId),
     Focused,
     Blurred,
     DirtyChanged,

crates/editor/src/items.rs

@@ -903,7 +903,7 @@ impl Item for Editor {
                 f(ItemEvent::UpdateBreadcrumbs);
             }
 
-            EditorEvent::Reparsed => {
+            EditorEvent::Reparsed(_) => {
                 f(ItemEvent::UpdateBreadcrumbs);
             }
 

crates/language_tools/src/syntax_tree_view.rs

@@ -110,7 +110,7 @@ impl SyntaxTreeView {
 
         let subscription = cx.subscribe(&editor, |this, _, event, cx| {
             let did_reparse = match event {
-                editor::EditorEvent::Reparsed => true,
+                editor::EditorEvent::Reparsed(_) => true,
                 editor::EditorEvent::SelectionsChanged { .. } => false,
                 _ => return,
             };

crates/multi_buffer/src/multi_buffer.rs

@@ -94,9 +94,9 @@ pub enum Event {
     DiffUpdated {
         buffer: Model<Buffer>,
     },
-    LanguageChanged,
+    LanguageChanged(BufferId),
     CapabilityChanged,
-    Reparsed,
+    Reparsed(BufferId),
     Saved,
     FileHandleChanged,
     Closed,
@@ -538,9 +538,13 @@ impl MultiBuffer {
         });
 
         if let Some(buffer) = self.as_singleton() {
-            return buffer.update(cx, |buffer, cx| {
+            buffer.update(cx, |buffer, cx| {
                 buffer.edit(edits, autoindent_mode, cx);
             });
+            cx.emit(Event::ExcerptsEdited {
+                ids: self.excerpt_ids(),
+            });
+            return;
         }
 
         let original_indent_columns = match &mut autoindent_mode {
@@ -1639,8 +1643,8 @@ impl MultiBuffer {
             language::Event::Reloaded => Event::Reloaded,
             language::Event::DiffBaseChanged => Event::DiffBaseChanged,
             language::Event::DiffUpdated => Event::DiffUpdated { buffer },
-            language::Event::LanguageChanged => Event::LanguageChanged,
-            language::Event::Reparsed => Event::Reparsed,
+            language::Event::LanguageChanged => Event::LanguageChanged(buffer.read(cx).remote_id()),
+            language::Event::Reparsed => Event::Reparsed(buffer.read(cx).remote_id()),
             language::Event::DiagnosticsUpdated => Event::DiagnosticsUpdated,
             language::Event::Closed => Event::Closed,
             language::Event::CapabilityChanged => {

crates/outline_panel/Cargo.toml

@@ -18,7 +18,8 @@ collections.workspace = true
 db.workspace = true
 editor.workspace = true
 file_icons.workspace = true
-git.workspace = true
+futures.workspace = true
+itertools.workspace = true
 gpui.workspace = true
 language.workspace = true
 log.workspace = true