Consistently expand or collapse all comments on a line (#176967)

* Remove redundant `show()` / `hide()` in `expand()` / `collapse()`

PR #176641 cleaned up the redundant, explicit calls to these methods in
`toggleExpand()` as they already happen in the
`onDidChangeCollapsibleState` listener if `_expanded` doesn't match the
new collapsible state. `hide()` was also adjusted there to call
`deleteCommentThread()` as needed.

* Consistently expand or collapse all comments on a line

Fixes #77155.

src/vs/workbench/contrib/comments/browser/commentThreadZoneWidget.ts

@@ -111,6 +111,10 @@ export class ReviewZoneWidget extends ZoneWidget implements ICommentThreadWidget
 		return this._commentThread;
 	}
 
+	public get expanded(): boolean | undefined {
+		return this._isExpanded;
+	}
+
 	private _commentOptions: languages.CommentOptions | undefined;
 
 	constructor(
@@ -257,22 +261,12 @@ export class ReviewZoneWidget extends ZoneWidget implements ICommentThreadWidget
 		this.commentService.disposeCommentThread(this.owner, this._commentThread.threadId);
 	}
 
-	public collapse(): Promise<void> {
+	public collapse() {
 		this._commentThread.collapsibleState = languages.CommentThreadCollapsibleState.Collapsed;
-		if (this._commentThread.comments && this._commentThread.comments.length === 0) {
-			this.deleteCommentThread();
-			return Promise.resolve();
-		}
-
-		this.hide();
-		return Promise.resolve();
 	}
 
-	public expand(): Promise<void> {
+	public expand() {
 		this._commentThread.collapsibleState = languages.CommentThreadCollapsibleState.Expanded;
-
-		this.show(this.arrowPosition(this._commentThread.range), 2);
-		return Promise.resolve();
 	}
 
 	public getGlyphPosition(): number {

src/vs/workbench/contrib/comments/browser/commentsController.ts

@@ -766,7 +766,8 @@ export class CommentController implements IEditorContribution {
 			// The widget's position is undefined until the widget has been displayed, so rely on the glyph position instead
 			const existingCommentsAtLine = this._commentWidgets.filter(widget => widget.getGlyphPosition() === commentRange.endLineNumber);
 			if (existingCommentsAtLine.length) {
-				existingCommentsAtLine.forEach(widget => widget.toggleExpand());
+				const allExpanded = existingCommentsAtLine.every(widget => widget.expanded);
+				existingCommentsAtLine.forEach(allExpanded ? widget => widget.collapse() : widget => widget.expand());
 				this.processNextThreadToAdd();
 				return;
 			} else {