Add registerWindowTitleVariable command

src/vs/workbench/browser/parts/titlebar/titlebarPart.ts

@@ -21,7 +21,7 @@ import { isMacintosh, isWindows, isLinux, isWeb, isNative, platformLocale } from
 import { Color } from 'vs/base/common/color';
 import { EventType, EventHelper, Dimension, append, $, addDisposableListener, prepend, reset, getWindow, getWindowId, isAncestor, getActiveDocument, isHTMLElement } from 'vs/base/browser/dom';
 import { CustomMenubarControl } from 'vs/workbench/browser/parts/titlebar/menubarControl';
-import { IInstantiationService } from 'vs/platform/instantiation/common/instantiation';
+import { IInstantiationService, ServicesAccessor } from 'vs/platform/instantiation/common/instantiation';
 import { Emitter, Event } from 'vs/base/common/event';
 import { IStorageService, StorageScope } from 'vs/platform/storage/common/storage';
 import { Parts, IWorkbenchLayoutService, ActivityBarPosition, LayoutSettings, EditorActionsLocation, EditorTabsMode } from 'vs/workbench/services/layout/browser/layoutService';
@@ -55,6 +55,7 @@ import { IView } from 'vs/base/browser/ui/grid/grid';
 import { createInstantHoverDelegate } from 'vs/base/browser/ui/hover/hoverDelegateFactory';
 import { IBaseActionViewItemOptions } from 'vs/base/browser/ui/actionbar/actionViewItems';
 import { IHoverDelegate } from 'vs/base/browser/ui/hover/hoverDelegate';
+import { CommandsRegistry } from 'vs/platform/commands/common/commands';
 
 export interface ITitleVariable {
 	readonly name: string;
@@ -83,6 +84,11 @@ export interface ITitlebarPart extends IDisposable {
 	 * Adds variables to be supported in the window title.
 	 */
 	registerVariables(variables: ITitleVariable[]): void;
+
+	/**
+	 * Unregisters variables from being supported in the window title.
+	 */
+	unregisterVariables(variableNames: string[]): void;
 }
 
 export class BrowserTitleService extends MultiWindowParts<BrowserTitlebarPart> implements ITitleService {
@@ -101,6 +107,7 @@ export class BrowserTitleService extends MultiWindowParts<BrowserTitlebarPart> i
 		this._register(this.registerPart(this.mainPart));
 
 		this.registerActions();
+		this.registerCommands();
 	}
 
 	protected createMainTitlebarPart(): BrowserTitlebarPart {
@@ -128,6 +135,39 @@ export class BrowserTitleService extends MultiWindowParts<BrowserTitlebarPart> i
 		}));
 	}
 
+	private registerCommands(): void {
+		this._register(CommandsRegistry.registerCommand({
+			id: 'registerWindowTitleVariable',
+			handler: (accessor: ServicesAccessor, name: string, contextKey: string) => {
+				if (accessor.get(IContextKeyService).getContextKeyValue(contextKey) === undefined) {
+					console.error(`Unable to register window title variable: Context key '${contextKey}' is not defined.`);
+					return;
+				}
+				this.registerVariables([{ name, contextKey }]);
+			},
+			metadata: {
+				description: 'Registers a new title variable',
+				args: [
+					{ name: 'name', schema: { type: 'string' }, description: 'The name of the variable to register' },
+					{ name: 'contextKey', schema: { type: 'string' }, description: 'The context key to use for the value of the variable' }
+				]
+			}
+		}));
+
+		this._register(CommandsRegistry.registerCommand({
+			id: 'unregisterWindowTitleVariable',
+			handler: (_, name: string) => {
+				this.unregisterVariables([name]);
+			},
+			metadata: {
+				description: 'Unregister a title variable',
+				args: [
+					{ name: 'name', schema: { type: 'string' }, description: 'The name of the variable to unregister' },
+				]
+			}
+		}));
+	}
+
 	//#region Auxiliary Titlebar Parts
 
 	createAuxiliaryTitlebarPart(container: HTMLElement, editorGroupsContainer: IEditorGroupsContainer): IAuxiliaryTitlebarPart {
@@ -182,10 +222,33 @@ export class BrowserTitleService extends MultiWindowParts<BrowserTitlebarPart> i
 	private variables: ITitleVariable[] = [];
 
 	registerVariables(variables: ITitleVariable[]): void {
-		this.variables.push(...variables);
+		const unregisteredVariables: ITitleVariable[] = [];
+
+		// Filter out any variables that are already registered
+		const existingVariableNames = new Set(this.variables.map(v => v.name));
+		const existingVariableContexKeys = new Set(this.variables.map(v => v.contextKey));
+		for (const v of variables) {
+			if (existingVariableNames.has(v.name)) {
+				console.error(`A title variable with the name '${v.name}' is already registered.`);
+			} else if (existingVariableContexKeys.has(v.contextKey)) {
+				console.error(`A title variable with the context key '${v.contextKey}' is already registered.`);
+			} else {
+				unregisteredVariables.push(v);
+			}
+		}
+
+		this.variables.push(...unregisteredVariables);
 
 		for (const part of this.parts) {
-			part.registerVariables(variables);
+			part.registerVariables(unregisteredVariables);
+		}
+	}
+
+	unregisterVariables(variableNames: string[]): void {
+		this.variables = this.variables.filter(v => !variableNames.includes(v.name));
+
+		for (const part of this.parts) {
+			part.unregisterVariables(variableNames);
 		}
 	}
 
@@ -400,6 +463,10 @@ export class BrowserTitlebarPart extends Part implements ITitlebarPart {
 		this.windowTitle.registerVariables(variables);
 	}
 
+	unregisterVariables(variableNames: string[]): void {
+		this.windowTitle.unregisterVariables(variableNames);
+	}
+
 	protected override createContentArea(parent: HTMLElement): HTMLElement {
 		this.element = parent;
 		this.rootContainer = append(parent, $('.titlebar-container'));

src/vs/workbench/browser/parts/titlebar/windowTitle.ts

@@ -268,6 +268,22 @@ export class WindowTitle extends Disposable {
 		}
 	}
 
+	unregisterVariables(variableNames: string[]): void {
+		let changed = false;
+
+		for (const [contextKey, name] of this.variables) {
+			if (variableNames.includes(name)) {
+				this.variables.delete(contextKey);
+
+				changed = true;
+			}
+		}
+
+		if (changed) {
+			this.titleUpdater.schedule();
+		}
+	}
+
 	/**
 	 * Possible template values:
 	 *

src/vs/workbench/contrib/scm/browser/activity.ts

@@ -5,7 +5,7 @@
 
 import { localize } from 'vs/nls';
 import { basename } from 'vs/base/common/resources';
-import { Disposable, DisposableStore } from 'vs/base/common/lifecycle';
+import { Disposable, DisposableStore, toDisposable } from 'vs/base/common/lifecycle';
 import { Emitter, Event } from 'vs/base/common/event';
 import { VIEW_PANE_ID, ISCMService, ISCMRepository, ISCMViewService } from 'vs/workbench/contrib/scm/common/scm';
 import { IActivityService, NumberBadge } from 'vs/workbench/services/activity/common/activity';
@@ -116,10 +116,12 @@ export class SCMActiveRepositoryController extends Disposable implements IWorkbe
 		this._activeRepositoryNameContextKey = ActiveRepositoryContextKeys.ActiveRepositoryName.bindTo(this.contextKeyService);
 		this._activeRepositoryBranchNameContextKey = ActiveRepositoryContextKeys.ActiveRepositoryBranchName.bindTo(this.contextKeyService);
 
-		this.titleService.registerVariables([
+		const titleVariables = [
 			{ name: 'activeRepositoryName', contextKey: ActiveRepositoryContextKeys.ActiveRepositoryName.key },
 			{ name: 'activeRepositoryBranchName', contextKey: ActiveRepositoryContextKeys.ActiveRepositoryBranchName.key, }
-		]);
+		];
+		this.titleService.registerVariables(titleVariables);
+		this._register(toDisposable(() => this.titleService.unregisterVariables(titleVariables.map(v => v.name))));
 
 		this._register(autorunWithStore((reader, store) => {
 			this._updateActivityCountBadge(this._countBadge.read(reader), store);