Merge pull request #71292 from Microsoft:joao/fix-68385

Stop the Settings tree from jittering

src/vs/base/browser/ui/list/list.ts

@@ -11,6 +11,7 @@ export interface IListVirtualDelegate<T> {
 	getHeight(element: T): number;
 	getTemplateId(element: T): string;
 	hasDynamicHeight?(element: T): boolean;
+	setDynamicHeight?(element: T, height: number): void;
 }
 
 export interface IListRenderer<T, TTemplateData> {

src/vs/base/browser/ui/list/listView.ts

@@ -1096,6 +1096,11 @@ export class ListView<T> implements ISpliceable<T>, IDisposable {
 		}
 
 		item.size = row.domNode!.offsetHeight;
+
+		if (this.virtualDelegate.setDynamicHeight) {
+			this.virtualDelegate.setDynamicHeight(item.element, item.size);
+		}
+
 		item.lastDynamicHeightWidth = this.renderWidth;
 		this.rowsContainer.removeChild(row.domNode!);
 		this.cache.release(row);

src/vs/base/browser/ui/tree/abstractTree.ts

@@ -178,6 +178,12 @@ export class ComposedTreeDelegate<T, N extends { element: T }> implements IListV
 	hasDynamicHeight(element: N): boolean {
 		return !!this.delegate.hasDynamicHeight && this.delegate.hasDynamicHeight(element.element);
 	}
+
+	setDynamicHeight(element: N, height: number): void {
+		if (this.delegate.setDynamicHeight) {
+			this.delegate.setDynamicHeight(element.element, height);
+		}
+	}
 }
 
 interface ITreeListTemplateData<T> {

src/vs/workbench/contrib/preferences/browser/settingsTree.ts

@@ -1220,7 +1220,16 @@ export class SettingsTreeFilter implements ITreeFilter<SettingsTreeElement> {
 }
 
 class SettingsTreeDelegate implements IListVirtualDelegate<SettingsTreeGroupChild> {
-	getHeight(element: SettingsTreeElement): number {
+
+	private heightCache = new WeakMap<SettingsTreeGroupChild, number>();
+
+	getHeight(element: SettingsTreeGroupChild): number {
+		const cachedHeight = this.heightCache.get(element);
+
+		if (typeof cachedHeight === 'number') {
+			return cachedHeight;
+		}
+
 		if (element instanceof SettingsTreeGroupElement) {
 			if (element.isFirstGroup) {
 				return 31;
@@ -1273,6 +1282,10 @@ class SettingsTreeDelegate implements IListVirtualDelegate<SettingsTreeGroupChil
 	hasDynamicHeight(element: SettingsTreeGroupElement | SettingsTreeSettingElement | SettingsTreeNewExtensionsElement): boolean {
 		return !(element instanceof SettingsTreeGroupElement);
 	}
+
+	setDynamicHeight(element: SettingsTreeGroupChild, height: number): void {
+		this.heightCache.set(element, height);
+	}
 }
 
 class NonCollapsibleObjectTreeModel<T> extends ObjectTreeModel<T> {