Add show method to webview view

Fixes #106085

src/vs/vscode.proposed.d.ts

@@ -2095,6 +2095,15 @@ declare module 'vscode' {
 		 * Note that hiding a view using the context menu instead disposes of the view and fires `onDidDispose`.
 		 */
 		readonly onDidChangeVisibility: Event<void>;
+
+		/**
+		 * Reveal the view in the UI.
+		 *
+		 * If the view is collapsed, this will expand it.
+		 *
+		 * @param preserveFocus When `true` the view will not take focus.
+		 */
+		show(preserveFocus?: boolean): void;
 	}
 
 	interface WebviewViewResolveContext<T = unknown> {

src/vs/workbench/api/browser/mainThreadWebviewViews.ts

@@ -38,6 +38,11 @@ export class MainThreadWebviewsViews extends Disposable implements extHostProtoc
 		webviewView.description = value;
 	}
 
+	public $show(handle: extHostProtocol.WebviewHandle, preserveFocus: boolean): void {
+		const webviewView = this.getWebviewView(handle);
+		webviewView.show(preserveFocus);
+	}
+
 	public $registerWebviewViewProvider(viewType: string, options?: { retainContextWhenHidden?: boolean }): void {
 		if (this._webviewViewProviders.has(viewType)) {
 			throw new Error(`View provider for ${viewType} already registered`);

src/vs/workbench/api/common/extHost.protocol.ts

@@ -641,6 +641,8 @@ export interface MainThreadWebviewViewsShape extends IDisposable {
 
 	$setWebviewViewTitle(handle: WebviewHandle, value: string | undefined): void;
 	$setWebviewViewDescription(handle: WebviewHandle, value: string | undefined): void;
+
+	$show(handle: WebviewHandle, preserveFocus: boolean): void;
 }
 
 export interface WebviewPanelViewStateData {

src/vs/workbench/api/common/extHostWebviewView.ts

@@ -99,6 +99,11 @@ class ExtHostWebviewView extends Disposable implements vscode.WebviewView {
 		this.#onDidChangeVisibility.fire();
 	}
 
+	public show(preserveFocus?: boolean): void {
+		this.assertNotDisposed();
+		this.#proxy.$show(this.#handle, !!preserveFocus);
+	}
+
 	private assertNotDisposed() {
 		if (this.#isDisposed) {
 			throw new Error('Webview is disposed');

src/vs/workbench/contrib/webviewView/browser/webviewViewPane.ts

@@ -21,7 +21,7 @@ import { IThemeService } from 'vs/platform/theme/common/themeService';
 import { ViewPane } from 'vs/workbench/browser/parts/views/viewPaneContainer';
 import { IViewletViewOptions } from 'vs/workbench/browser/parts/views/viewsViewlet';
 import { Memento, MementoObject } from 'vs/workbench/common/memento';
-import { IViewDescriptorService } from 'vs/workbench/common/views';
+import { IViewDescriptorService, IViewsService } from 'vs/workbench/common/views';
 import { IWebviewService, WebviewOverlay } from 'vs/workbench/contrib/webview/browser/webview';
 import { IWebviewViewService, WebviewView } from 'vs/workbench/contrib/webviewView/browser/webviewViewService';
 import { IExtensionService } from 'vs/workbench/services/extensions/common/extensions';
@@ -57,6 +57,7 @@ export class WebviewViewPane extends ViewPane {
 		@IProgressService private readonly progressService: IProgressService,
 		@IWebviewService private readonly webviewService: IWebviewService,
 		@IWebviewViewService private readonly webviewViewService: IWebviewViewService,
+		@IViewsService private readonly viewService: IViewsService,
 	) {
 		super({ ...options, titleMenuId: MenuId.ViewTitle }, keybindingService, contextMenuService, configurationService, contextKeyService, viewDescriptorService, instantiationService, openerService, themeService, telemetryService);
 
@@ -168,6 +169,10 @@ export class WebviewViewPane extends ViewPane {
 
 					get description(): string | undefined { return self.titleDescription; },
 					set description(value: string | undefined) { self.updateTitleDescription(value); },
+
+					show: (preserveFocus) => {
+						this.viewService.openView(this.id, !preserveFocus);
+					}
 				};
 
 				await this.webviewViewService.resolve(this.id, webviewView, source.token);

src/vs/workbench/contrib/webviewView/browser/webviewViewService.ts

@@ -19,6 +19,8 @@ export interface WebviewView {
 
 	readonly onDidChangeVisibility: Event<boolean>;
 	readonly onDispose: Event<void>;
+
+	show(preserveFocus: boolean): void;
 }
 
 export interface IWebviewViewResolver {