Delay updateStyleSheet until we are starting the workbench

src/vs/workbench/contrib/customEditor/browser/customEditorInput.ts

@@ -14,6 +14,7 @@ import { URI } from 'vs/base/common/uri';
 import { WebviewContentState } from 'vs/editor/common/modes';
 import { IDialogService } from 'vs/platform/dialogs/common/dialogs';
 import { ILabelService } from 'vs/platform/label/common/label';
+import { ILifecycleService } from 'vs/platform/lifecycle/common/lifecycle';
 import { ConfirmResult, IEditorInput, Verbosity } from 'vs/workbench/common/editor';
 import { WebviewEditorOverlay } from 'vs/workbench/contrib/webview/browser/webview';
 import { IWebviewWorkbenchService, LazilyResolvedWebviewEditorInput } from 'vs/workbench/contrib/webview/browser/webviewWorkbenchService';
@@ -31,11 +32,12 @@ export class CustomFileEditorInput extends LazilyResolvedWebviewEditorInput {
 		viewType: string,
 		id: string,
 		webview: Lazy<UnownedDisposable<WebviewEditorOverlay>>,
+		@ILifecycleService lifecycleService: ILifecycleService,
 		@IWebviewWorkbenchService webviewWorkbenchService: IWebviewWorkbenchService,
 		@IDialogService private readonly dialogService: IDialogService,
 		@ILabelService private readonly labelService: ILabelService,
 	) {
-		super(id, viewType, '', webview, webviewWorkbenchService);
+		super(id, viewType, '', webview, webviewWorkbenchService, lifecycleService);
 		this._editorResource = resource;
 	}
 

src/vs/workbench/contrib/webview/browser/webviewEditorInput.ts

@@ -9,6 +9,7 @@ import { Lazy } from 'vs/base/common/lazy';
 import { UnownedDisposable as Unowned } from 'vs/base/common/lifecycle';
 import { URI } from 'vs/base/common/uri';
 import { IEditorModel } from 'vs/platform/editor/common/editor';
+import { ILifecycleService, LifecyclePhase } from 'vs/platform/lifecycle/common/lifecycle';
 import { EditorInput, EditorModel, GroupIdentifier, IEditorInput, Verbosity } from 'vs/workbench/common/editor';
 import { WebviewEditorOverlay } from 'vs/workbench/contrib/webview/browser/webview';
 
@@ -17,6 +18,7 @@ const WebviewPanelResourceScheme = 'webview-panel';
 class WebviewIconsManager {
 	private readonly _icons = new Map<string, { light: URI, dark: URI }>();
 
+
 	@memoize
 	private get _styleElement(): HTMLStyleElement {
 		const element = dom.createStyleSheet();
@@ -26,7 +28,8 @@ class WebviewIconsManager {
 
 	public setIcons(
 		webviewId: string,
-		iconPath: { light: URI, dark: URI } | undefined
+		iconPath: { light: URI, dark: URI } | undefined,
+		lifecycleService: ILifecycleService,
 	) {
 		if (iconPath) {
 			this._icons.set(webviewId, iconPath);
@@ -34,10 +37,11 @@ class WebviewIconsManager {
 			this._icons.delete(webviewId);
 		}
 
-		this.updateStyleSheet();
+		this.updateStyleSheet(lifecycleService);
 	}
 
-	private updateStyleSheet() {
+	private async updateStyleSheet(lifecycleService: ILifecycleService, ) {
+		await lifecycleService.when(LifecyclePhase.Starting);
 		const cssRules: string[] = [];
 		this._icons.forEach((value, key) => {
 			const webviewSelector = `.show-file-icons .webview-${key}-name-file-icon::before`;
@@ -67,7 +71,8 @@ export class WebviewInput extends EditorInput {
 		public readonly id: string,
 		public readonly viewType: string,
 		name: string,
-		webview: Lazy<Unowned<WebviewEditorOverlay>>
+		webview: Lazy<Unowned<WebviewEditorOverlay>>,
+		@ILifecycleService private readonly lifecycleService: ILifecycleService,
 	) {
 		super();
 
@@ -118,7 +123,7 @@ export class WebviewInput extends EditorInput {
 
 	public set iconPath(value: { light: URI, dark: URI } | undefined) {
 		this._iconPath = value;
-		WebviewInput.iconsManager.setIcons(this.id, value);
+		WebviewInput.iconsManager.setIcons(this.id, value, this.lifecycleService);
 	}
 
 	public matches(other: IEditorInput): boolean {

src/vs/workbench/contrib/webview/browser/webviewWorkbenchService.ts

@@ -5,19 +5,20 @@
 
 import { equals } from 'vs/base/common/arrays';
 import { memoize } from 'vs/base/common/decorators';
+import { Lazy } from 'vs/base/common/lazy';
 import { IDisposable, toDisposable, UnownedDisposable } from 'vs/base/common/lifecycle';
 import { values } from 'vs/base/common/map';
 import { isEqual } from 'vs/base/common/resources';
 import { URI } from 'vs/base/common/uri';
 import { EditorActivation, IEditorModel } from 'vs/platform/editor/common/editor';
 import { registerSingleton } from 'vs/platform/instantiation/common/extensions';
-import { createDecorator } from 'vs/platform/instantiation/common/instantiation';
+import { createDecorator, IInstantiationService } from 'vs/platform/instantiation/common/instantiation';
+import { ILifecycleService } from 'vs/platform/lifecycle/common/lifecycle';
 import { GroupIdentifier } from 'vs/workbench/common/editor';
-import { IWebviewService, WebviewContentOptions, WebviewEditorOverlay, WebviewOptions, WebviewExtensionDescription } from 'vs/workbench/contrib/webview/browser/webview';
+import { IWebviewService, WebviewContentOptions, WebviewEditorOverlay, WebviewExtensionDescription, WebviewOptions } from 'vs/workbench/contrib/webview/browser/webview';
 import { IEditorGroup, IEditorGroupsService } from 'vs/workbench/services/editor/common/editorGroupsService';
 import { ACTIVE_GROUP_TYPE, IEditorService, SIDE_GROUP_TYPE } from 'vs/workbench/services/editor/common/editorService';
 import { WebviewInput } from './webviewEditorInput';
-import { Lazy } from 'vs/base/common/lazy';
 
 export const IWebviewWorkbenchService = createDecorator<IWebviewWorkbenchService>('webviewEditorService');
 
@@ -109,8 +110,9 @@ export class LazilyResolvedWebviewEditorInput extends WebviewInput {
 		name: string,
 		webview: Lazy<UnownedDisposable<WebviewEditorOverlay>>,
 		@IWebviewWorkbenchService private readonly _webviewWorkbenchService: IWebviewWorkbenchService,
+		@ILifecycleService lifeCycleService: ILifecycleService,
 	) {
-		super(id, viewType, name, webview);
+		super(id, viewType, name, webview, lifeCycleService);
 	}
 
 	@memoize
@@ -145,8 +147,9 @@ export class WebviewEditorService implements IWebviewWorkbenchService {
 	private readonly _revivalPool = new RevivalPool();
 
 	constructor(
-		@IEditorService private readonly _editorService: IEditorService,
 		@IEditorGroupsService private readonly _editorGroupService: IEditorGroupsService,
+		@IEditorService private readonly _editorService: IEditorService,
+		@IInstantiationService private readonly _instantiationService: IInstantiationService,
 		@IWebviewService private readonly _webviewService: IWebviewService,
 	) { }
 
@@ -159,7 +162,7 @@ export class WebviewEditorService implements IWebviewWorkbenchService {
 		extension: WebviewExtensionDescription | undefined,
 	): WebviewInput {
 		const webview = new Lazy(() => new UnownedDisposable(this.createWebiew(id, extension, options)));
-		const webviewInput = new WebviewInput(id, viewType, title, webview);
+		const webviewInput = this._instantiationService.createInstance(WebviewInput, id, viewType, title, webview);
 		this._editorService.openEditor(webviewInput, {
 			pinned: true,
 			preserveFocus: showOptions.preserveFocus,
@@ -206,7 +209,7 @@ export class WebviewEditorService implements IWebviewWorkbenchService {
 			return new UnownedDisposable(webview);
 		});
 
-		const webviewInput = new LazilyResolvedWebviewEditorInput(id, viewType, title, webview, this);
+		const webviewInput = this._instantiationService.createInstance(LazilyResolvedWebviewEditorInput, id, viewType, title, webview);
 		webviewInput.iconPath = iconPath;
 
 		if (typeof group === 'number') {