Fix #79519

src/vs/workbench/browser/parts/views/views.ts

@@ -11,7 +11,7 @@ import { IStorageService, StorageScope } from 'vs/platform/storage/common/storag
 import { IViewletService } from 'vs/workbench/services/viewlet/browser/viewlet';
 import { IContextKeyService, IContextKeyChangeEvent, IReadableSet, IContextKey, RawContextKey, ContextKeyExpr } from 'vs/platform/contextkey/common/contextkey';
 import { Event, Emitter } from 'vs/base/common/event';
-import { sortedDiff, firstIndex, move, isNonEmptyArray } from 'vs/base/common/arrays';
+import { firstIndex, move, isNonEmptyArray } from 'vs/base/common/arrays';
 import { isUndefinedOrNull, isUndefined } from 'vs/base/common/types';
 import { MenuId, MenuRegistry, ICommandAction } from 'vs/platform/actions/common/actions';
 import { CommandsRegistry } from 'vs/platform/commands/common/commands';
@@ -223,7 +223,11 @@ export interface IAddedViewDescriptorRef extends IViewDescriptorRef {
 
 export class ContributableViewsModel extends Disposable {
 
-	readonly viewDescriptors: IViewDescriptor[] = [];
+	private _viewDescriptors: IViewDescriptor[] = [];
+	get viewDescriptors(): ReadonlyArray<IViewDescriptor> {
+		return this._viewDescriptors;
+	}
+
 	get visibleViewDescriptors(): IViewDescriptor[] {
 		return this.viewDescriptors.filter(v => this.isViewDescriptorVisible(v));
 	}
@@ -240,8 +244,8 @@ export class ContributableViewsModel extends Disposable {
 	private _onDidChangeViewState = this._register(new Emitter<IViewDescriptorRef>());
 	protected readonly onDidChangeViewState: Event<IViewDescriptorRef> = this._onDidChangeViewState.event;
 
-	private _onDidChangeActiveViews = this._register(new Emitter<IViewDescriptor[]>());
-	readonly onDidChangeActiveViews: Event<IViewDescriptor[]> = this._onDidChangeActiveViews.event;
+	private _onDidChangeActiveViews = this._register(new Emitter<ReadonlyArray<IViewDescriptor>>());
+	readonly onDidChangeActiveViews: Event<ReadonlyArray<IViewDescriptor>> = this._onDidChangeActiveViews.event;
 
 	constructor(
 		container: ViewContainer,
@@ -338,7 +342,7 @@ export class ContributableViewsModel extends Disposable {
 		const fromViewDescriptor = this.viewDescriptors[fromIndex];
 		const toViewDescriptor = this.viewDescriptors[toIndex];
 
-		move(this.viewDescriptors, fromIndex, toIndex);
+		move(this._viewDescriptors, fromIndex, toIndex);
 
 		for (let index = 0; index < this.viewDescriptors.length; index++) {
 			const state = this.viewStates.get(this.viewDescriptors[index].id)!;
@@ -384,7 +388,7 @@ export class ContributableViewsModel extends Disposable {
 			return 0;
 		}
 
-		return (this.getViewOrder(a) - this.getViewOrder(b)) || this.getGroupOrderResult(a, b) || (a.id < b.id ? -1 : 1);
+		return (this.getViewOrder(a) - this.getViewOrder(b)) || this.getGroupOrderResult(a, b);
 	}
 
 	private getGroupOrderResult(a: IViewDescriptor, b: IViewDescriptor) {
@@ -406,14 +410,6 @@ export class ContributableViewsModel extends Disposable {
 	}
 
 	private onDidChangeViewDescriptors(viewDescriptors: IViewDescriptor[]): void {
-		const ids = new Set<string>();
-
-		for (const viewDescriptor of this.viewDescriptors) {
-			ids.add(viewDescriptor.id);
-		}
-
-		viewDescriptors = viewDescriptors.sort(this.compareViewDescriptors.bind(this));
-
 		for (const viewDescriptor of viewDescriptors) {
 			const viewState = this.viewStates.get(viewDescriptor.id);
 			if (viewState) {
@@ -433,38 +429,26 @@ export class ContributableViewsModel extends Disposable {
 			}
 		}
 
-		const splices = sortedDiff<IViewDescriptor>(
-			this.viewDescriptors,
-			viewDescriptors,
-			this.compareViewDescriptors.bind(this)
-		).reverse();
-
 		const toRemove: { index: number, viewDescriptor: IViewDescriptor; }[] = [];
 		const toAdd: { index: number, viewDescriptor: IViewDescriptor, size?: number, collapsed: boolean; }[] = [];
 
-		for (const splice of splices) {
-			const startViewDescriptor = this.viewDescriptors[splice.start];
-			let startIndex = startViewDescriptor ? this.find(startViewDescriptor.id).visibleIndex : this.viewDescriptors.length;
-
-			for (let i = 0; i < splice.deleteCount; i++) {
-				const viewDescriptor = this.viewDescriptors[splice.start + i];
+		const previous = this._viewDescriptors;
+		this._viewDescriptors = viewDescriptors.sort(this.compareViewDescriptors.bind(this));
 
-				if (this.isViewDescriptorVisible(viewDescriptor)) {
-					toRemove.push({ index: startIndex++, viewDescriptor });
-				}
+		for (let index = 0; index < previous.length; index++) {
+			if (this._viewDescriptors.every(viewDescriptor => viewDescriptor.id !== previous[index].id)) {
+				toRemove.push({ index, viewDescriptor: previous[index] });
 			}
+		}
 
-			for (const viewDescriptor of splice.toInsert) {
+		for (let index = 0; index < this._viewDescriptors.length; index++) {
+			const viewDescriptor = this._viewDescriptors[index];
+			if (previous.every(previousViewDescriptor => previousViewDescriptor.id !== viewDescriptor.id)) {
 				const state = this.viewStates.get(viewDescriptor.id)!;
-
-				if (this.isViewDescriptorVisible(viewDescriptor)) {
-					toAdd.push({ index: startIndex++, viewDescriptor, size: state.size, collapsed: !!state.collapsed });
-				}
+				toAdd.push({ index, viewDescriptor, size: state.size, collapsed: !!state.collapsed });
 			}
 		}
 
-		this.viewDescriptors.splice(0, this.viewDescriptors.length, ...viewDescriptors);
-
 		if (toRemove.length) {
 			this._onDidRemove.fire(toRemove);
 		}

src/vs/workbench/browser/parts/views/viewsViewlet.ts

@@ -354,7 +354,7 @@ export abstract class FilterViewContainerViewlet extends ViewContainerViewlet {
 		}));
 	}
 
-	private updateAllViews(viewDescriptors: IViewDescriptor[]) {
+	private updateAllViews(viewDescriptors: ReadonlyArray<IViewDescriptor>) {
 		viewDescriptors.forEach(descriptor => {
 			let filterOnValue = this.getFilterOn(descriptor);
 			if (!filterOnValue) {