Only update layout when chat is visible (microsoft#191943)

Fixes microsoft#191942

Author: TylerLeonhardt

src/vs/workbench/contrib/chat/browser/chatQuick.ts

@@ -134,6 +134,7 @@ class QuickChat extends Disposable {
 	private model: ChatModel | undefined;
 	private _currentQuery: string | undefined;
 	private maintainScrollTimer: MutableDisposable<IDisposable> = this._register(new MutableDisposable<IDisposable>());
+	private _deferUpdatingDynamicLayout: boolean = false;
 
 	constructor(
 		private readonly _options: IChatViewOptions,
@@ -183,6 +184,10 @@ class QuickChat extends Disposable {
 		this.widget.setVisible(true);
 		// If the mutable disposable is set, then we are keeping the existing scroll position
 		// so we should not update the layout.
+		if (this._deferUpdatingDynamicLayout) {
+			this._deferUpdatingDynamicLayout = false;
+			this.widget.updateDynamicChatTreeItemLayout(2, this.maxHeight);
+		}
 		if (!this.maintainScrollTimer.value) {
 			this.widget.layoutDynamicChatTreeItemMode();
 		}
@@ -222,7 +227,14 @@ class QuickChat extends Disposable {
 
 	private registerListeners(parent: HTMLElement): void {
 		this._register(this.layoutService.onDidLayout(() => {
-			this.widget.updateDynamicChatTreeItemLayout(2, this.maxHeight);
+			if (this.widget.visible) {
+				this.widget.updateDynamicChatTreeItemLayout(2, this.maxHeight);
+			} else {
+				// If the chat is not visible, then we should defer updating the layout
+				// because it relies on offsetHeight which only works correctly
+				// when the chat is visible.
+				this._deferUpdatingDynamicLayout = true;
+			}
 		}));
 		this._register(this.widget.inputEditor.onDidChangeModelContent((e) => {
 			this._currentQuery = this.widget.inputEditor.getValue();

src/vs/workbench/contrib/chat/browser/chatWidget.ts

@@ -77,9 +77,12 @@ export class ChatWidget extends Disposable implements IChatWidget {
 	private container!: HTMLElement;
 
 	private bodyDimension: dom.Dimension | undefined;
-	private visible = false;
 	private visibleChangeCount = 0;
 	private requestInProgress: IContextKey<boolean>;
+	private _visible = false;
+	public get visible() {
+		return this._visible;
+	}
 
 	private previousTreeScrollHeight: number = 0;
 
@@ -214,7 +217,7 @@ export class ChatWidget extends Disposable implements IChatWidget {
 	}
 
 	private onDidChangeItems(skipDynamicLayout?: boolean) {
-		if (this.tree && this.visible) {
+		if (this.tree && this._visible) {
 			const treeItems = (this.viewModel?.getItems() ?? [])
 				.map(item => {
 					return <ITreeElement<ChatTreeItem>>{
@@ -261,15 +264,15 @@ export class ChatWidget extends Disposable implements IChatWidget {
 	}
 
 	setVisible(visible: boolean): void {
-		this.visible = visible;
+		this._visible = visible;
 		this.visibleChangeCount++;
 		this.renderer.setVisible(visible);
 
 		if (visible) {
 			this._register(disposableTimeout(() => {
 				// Progressive rendering paused while hidden, so start it up again.
 				// Do it after a timeout because the container is not visible yet (it should be but offsetHeight returns 0 here)
-				if (this.visible) {
+				if (this._visible) {
 					this.onDidChangeItems(true);
 				}
 			}, 0));