Add webview restoration api proposal (#46380)

Adds a proposed webiew serialization api that allows webviews to be restored automatically when vscode restarts

extensions/markdown-language-features/package.json

@@ -22,7 +22,8 @@
 		"onCommand:markdown.showPreviewToSide",
 		"onCommand:markdown.showLockedPreviewToSide",
 		"onCommand:markdown.showSource",
-		"onCommand:markdown.showPreviewSecuritySelector"
+		"onCommand:markdown.showPreviewSecuritySelector",
+		"onView:markdown.preview"
 	],
 	"contributes": {
 		"commands": [

extensions/markdown-language-features/src/features/preview.ts

@@ -18,37 +18,85 @@ const localize = nls.loadMessageBundle();
 
 export class MarkdownPreview {
 
-	public static previewViewType = 'markdown.preview';
+	public static viewType = 'markdown.preview';
 
 	private readonly webview: vscode.Webview;
 	private throttleTimer: any;
-	private initialLine: number | undefined = undefined;
+	private line: number | undefined = undefined;
 	private readonly disposables: vscode.Disposable[] = [];
 	private firstUpdate = true;
 	private currentVersion?: { resource: vscode.Uri, version: number };
 	private forceUpdate = false;
 	private isScrolling = false;
 
-	constructor(
+	public static revive(
-		private _resource: vscode.Uri,
+		webview: vscode.Webview,
+		state: any,
+		contentProvider: MarkdownContentProvider,
+		previewConfigurations: MarkdownPreviewConfigurationManager,
+		logger: Logger,
+		topmostLineMonitor: MarkdownFileTopmostLineMonitor
+	): MarkdownPreview {
+		const resource = vscode.Uri.parse(state.resource);
+		const locked = state.locked;
+		const line = state.line;
+
+		const preview = new MarkdownPreview(
+			webview,
+			resource,
+			locked,
+			contentProvider,
+			previewConfigurations,
+			logger,
+			topmostLineMonitor);
+
+		if (!isNaN(line)) {
+			preview.line = line;
+		}
+		return preview;
+	}
+
+	public static create(
+		resource: vscode.Uri,
 		previewColumn: vscode.ViewColumn,
-		public locked: boolean,
+		locked: boolean,
-		private readonly contentProvider: MarkdownContentProvider,
+		contentProvider: MarkdownContentProvider,
-		private readonly previewConfigurations: MarkdownPreviewConfigurationManager,
+		previewConfigurations: MarkdownPreviewConfigurationManager,
-		private readonly logger: Logger,
+		logger: Logger,
 		topmostLineMonitor: MarkdownFileTopmostLineMonitor,
-		private readonly contributions: MarkdownContributions
+		contributions: MarkdownContributions
-	) {
+	): MarkdownPreview {
-		this.webview = vscode.window.createWebview(
+		const webview = vscode.window.createWebview(
-			MarkdownPreview.previewViewType,
+			MarkdownPreview.viewType,
-			this.getPreviewTitle(this._resource),
+			MarkdownPreview.getPreviewTitle(resource, locked),
 			previewColumn, {
 				enableScripts: true,
 				enableCommandUris: true,
 				enableFindWidget: true,
-				localResourceRoots: this.getLocalResourceRoots(_resource)
+				localResourceRoots: MarkdownPreview.getLocalResourceRoots(resource, contributions)
 			});
 
+		return new MarkdownPreview(
+			webview,
+			resource,
+			locked,
+			contentProvider,
+			previewConfigurations,
+			logger,
+			topmostLineMonitor);
+	}
+
+	private constructor(
+		webview: vscode.Webview,
+		private _resource: vscode.Uri,
+		public locked: boolean,
+		private readonly contentProvider: MarkdownContentProvider,
+		private readonly previewConfigurations: MarkdownPreviewConfigurationManager,
+		private readonly logger: Logger,
+		topmostLineMonitor: MarkdownFileTopmostLineMonitor
+	) {
+		this.webview = webview;
+
 		this.webview.onDidDispose(() => {
 			this.dispose();
 		}, null, this.disposables);
@@ -111,6 +159,14 @@ export class MarkdownPreview {
 		return this._resource;
 	}
 
+	public get state() {
+		return {
+			resource: this.resource.toString(),
+			locked: this.locked,
+			line: this.line
+		};
+	}
+
 	public dispose() {
 		this._onDisposeEmitter.fire();
 
@@ -124,9 +180,7 @@ export class MarkdownPreview {
 	public update(resource: vscode.Uri) {
 		const editor = vscode.window.activeTextEditor;
 		if (editor && editor.document.uri.fsPath === resource.fsPath) {
-			this.initialLine = getVisibleLine(editor);
+			this.line = getVisibleLine(editor);
-		} else {
-			this.initialLine = undefined;
 		}
 
 		// If we have changed resources, cancel any pending updates
@@ -169,6 +223,10 @@ export class MarkdownPreview {
 		return this._resource.fsPath === resource.fsPath;
 	}
 
+	public isWebviewOf(webview: vscode.Webview): boolean {
+		return this.webview === webview;
+	}
+
 	public matchesResource(
 		otherResource: vscode.Uri,
 		otherViewColumn: vscode.ViewColumn | undefined,
@@ -195,11 +253,11 @@ export class MarkdownPreview {
 
 	public toggleLock() {
 		this.locked = !this.locked;
-		this.webview.title = this.getPreviewTitle(this._resource);
+		this.webview.title = MarkdownPreview.getPreviewTitle(this._resource, this.locked);
 	}
 
-	private getPreviewTitle(resource: vscode.Uri): string {
+	private static getPreviewTitle(resource: vscode.Uri, locked: boolean): string {
-		return this.locked
+		return locked
 			? localize('lockedPreviewTitle', '[Preview] {0}', path.basename(resource.fsPath))
 			: localize('previewTitle', 'Preview {0}', path.basename(resource.fsPath));
 	}
@@ -216,7 +274,7 @@ export class MarkdownPreview {
 
 		if (typeof topLine === 'number') {
 			this.logger.log('updateForView', { markdownFile: resource });
-			this.initialLine = topLine;
+			this.line = topLine;
 			this.webview.postMessage({
 				type: 'updateView',
 				line: topLine,
@@ -233,25 +291,28 @@ export class MarkdownPreview {
 
 		const document = await vscode.workspace.openTextDocument(resource);
 		if (!this.forceUpdate && this.currentVersion && this.currentVersion.resource.fsPath === resource.fsPath && this.currentVersion.version === document.version) {
-			if (this.initialLine) {
+			if (this.line) {
-				this.updateForView(resource, this.initialLine);
+				this.updateForView(resource, this.line);
 			}
 			return;
 		}
 		this.forceUpdate = false;
 
 		this.currentVersion = { resource, version: document.version };
-		this.contentProvider.provideTextDocumentContent(document, this.previewConfigurations, this.initialLine)
+		this.contentProvider.provideTextDocumentContent(document, this.previewConfigurations, this.line)
 			.then(content => {
 				if (this._resource === resource) {
-					this.webview.title = this.getPreviewTitle(this._resource);
+					this.webview.title = MarkdownPreview.getPreviewTitle(this._resource, this.locked);
 					this.webview.html = content;
 				}
 			});
 	}
 
-	private getLocalResourceRoots(resource: vscode.Uri): vscode.Uri[] {
+	private static getLocalResourceRoots(
-		const baseRoots = this.contributions.previewResourceRoots;
+		resource: vscode.Uri,
+		contributions: MarkdownContributions
+	): vscode.Uri[] {
+		const baseRoots = contributions.previewResourceRoots;
 
 		const folder = vscode.workspace.getWorkspaceFolder(resource);
 		if (folder) {
@@ -266,6 +327,7 @@ export class MarkdownPreview {
 	}
 
 	private onDidScrollPreview(line: number) {
+		this.line = line;
 		for (const editor of vscode.window.visibleTextEditors) {
 			if (!this.isPreviewOf(editor.document.uri)) {
 				continue;

extensions/markdown-language-features/src/features/previewManager.ts

@@ -14,7 +14,7 @@ import { isMarkdownFile } from '../util/file';
 import { MarkdownPreviewConfigurationManager } from './previewConfig';
 import { MarkdownContributions } from '../markdownExtensions';
 
-export class MarkdownPreviewManager {
+export class MarkdownPreviewManager implements vscode.WebviewSerializer {
 	private static readonly markdownPreviewActiveContextKey = 'markdownPreviewFocus';
 
 	private readonly topmostLineMonitor = new MarkdownFileTopmostLineMonitor();
@@ -29,15 +29,14 @@ export class MarkdownPreviewManager {
 		private readonly contributions: MarkdownContributions
 	) {
 		vscode.window.onDidChangeActiveTextEditor(editor => {
-			if (editor) {
+			if (editor && isMarkdownFile(editor.document)) {
-				if (isMarkdownFile(editor.document)) {
+				for (const preview of this.previews.filter(preview => !preview.locked)) {
-					for (const preview of this.previews.filter(preview => !preview.locked)) {
+					preview.update(editor.document.uri);
-						preview.update(editor.document.uri);
-					}
 				}
 			}
 		}, null, this.disposables);
 
+		this.disposables.push(vscode.window.registerWebviewSerializer(MarkdownPreview.viewType, this));
 	}
 
 	public dispose(): void {
@@ -66,7 +65,6 @@ export class MarkdownPreviewManager {
 			preview.reveal(previewSettings.previewColumn);
 		} else {
 			preview = this.createNewPreview(resource, previewSettings);
-			this.previews.push(preview);
 		}
 
 		preview.update(resource);
@@ -90,6 +88,30 @@ export class MarkdownPreviewManager {
 		}
 	}
 
+	public async deserializeWebview(
+		webview: vscode.Webview,
+		state: any
+	): Promise<boolean> {
+		const preview = MarkdownPreview.revive(
+			webview,
+			state,
+			this.contentProvider,
+			this.previewConfigurations,
+			this.logger,
+			this.topmostLineMonitor);
+
+		this.registerPreview(preview);
+		preview.refresh();
+		return true;
+	}
+
+	public async serializeWebview(
+		webview: vscode.Webview,
+	): Promise<any> {
+		const preview = this.previews.find(preview => preview.isWebviewOf(webview));
+		return preview ? preview.state : undefined;
+	}
+
 	private getExistingPreview(
 		resource: vscode.Uri,
 		previewSettings: PreviewSettings
@@ -101,8 +123,8 @@ export class MarkdownPreviewManager {
 	private createNewPreview(
 		resource: vscode.Uri,
 		previewSettings: PreviewSettings
-	) {
+	): MarkdownPreview {
-		const preview = new MarkdownPreview(
+		const preview = MarkdownPreview.create(
 			resource,
 			previewSettings.previewColumn,
 			previewSettings.locked,
@@ -112,6 +134,14 @@ export class MarkdownPreviewManager {
 			this.topmostLineMonitor,
 			this.contributions);
 
+		return this.registerPreview(preview);
+	}
+
+	private registerPreview(
+		preview: MarkdownPreview
+	): MarkdownPreview {
+		this.previews.push(preview);
+
 		preview.onDispose(() => {
 			const existing = this.previews.indexOf(preview!);
 			if (existing >= 0) {

src/vs/vscode.proposed.d.ts

@@ -568,7 +568,7 @@ declare module 'vscode' {
 	 */
 	export interface Webview {
 		/**
-		 * The type of the webview, such as `'markdownw.preview'`
+		 * The type of the webview, such as `'markdown.preview'`
 		 */
 		readonly viewType: string;
 
@@ -636,16 +636,57 @@ declare module 'vscode' {
 		dispose(): any;
 	}
 
+	/**
+	 * Save and restore webviews that have been persisted when vscode shuts down.
+	 */
+	interface WebviewSerializer {
+		/**
+		 * Save a webview's `state`.
+		 *
+		 * Called before shutdown. Webview may or may not be visible.
+		 *
+		 * @param webview Webview to serialize.
+		 *
+		 * @returns JSON serializable state blob.
+		 */
+		serializeWebview(webview: Webview): Thenable<any>;
+
+		/**
+		 * Restore a webview from its `state`.
+		 *
+		 * Called when a serialized webview first becomes active.
+		 *
+		 * @param webview Webview to restore. The serializer should take ownership of this webview.
+		 * @param state Persisted state.
+		 *
+		 * @return Was deserialization successful?
+		 */
+		deserializeWebview(webview: Webview, state: any): Thenable<boolean>;
+	}
+
 	namespace window {
 		/**
 		 * Create and show a new webview.
 		 *
-		 * @param viewType Identifier the type of the webview.
+		 * @param viewType Identifies the type of the webview.
 		 * @param title Title of the webview.
 		 * @param column Editor column to show the new webview in.
 		 * @param options Content settings for the webview.
 		 */
 		export function createWebview(viewType: string, title: string, column: ViewColumn, options: WebviewOptions): Webview;
+
+		/**
+		 * Registers a webview serializer.
+		 *
+		 * Extensions that support reviving should have an `"onView:viewType"` activation method and
+		 * make sure that `registerWebviewSerializer` is called during activation.
+		 *
+		 * Only a single serializer may be registered at a time for a given `viewType`.
+		 *
+		 * @param viewType Type of the webview that can be serialized.
+		 * @param reviver Webview serializer.
+		 */
+		export function registerWebviewSerializer(viewType: string, reviver: WebviewSerializer): Disposable;
 	}
 
 	//#endregion

src/vs/workbench/api/electron-browser/mainThreadWebview.ts

@@ -2,44 +2,58 @@
  *  Copyright (c) Microsoft Corporation. All rights reserved.
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
-
+import { IDisposable, dispose } from 'vs/base/common/lifecycle';
 import * as map from 'vs/base/common/map';
-import { MainThreadWebviewsShape, MainContext, IExtHostContext, ExtHostContext, ExtHostWebviewsShape, WebviewHandle } from 'vs/workbench/api/node/extHost.protocol';
-import { dispose, Disposable } from 'vs/base/common/lifecycle';
-import { extHostNamedCustomer } from './extHostCustomers';
-import { Position } from 'vs/platform/editor/common/editor';
-import { IWorkbenchEditorService } from 'vs/workbench/services/editor/common/editorService';
-import { IContextKeyService } from 'vs/platform/contextkey/common/contextkey';
-import { IPartService } from 'vs/workbench/services/part/common/partService';
-import { IOpenerService } from 'vs/platform/opener/common/opener';
-import * as vscode from 'vscode';
-import { IEditorGroupService } from 'vs/workbench/services/group/common/groupService';
 import URI from 'vs/base/common/uri';
-import { WebviewInput } from 'vs/workbench/parts/webview/electron-browser/webviewInput';
+import { TPromise } from 'vs/base/common/winjs.base';
+import { IContextKeyService } from 'vs/platform/contextkey/common/contextkey';
+import { Position } from 'vs/platform/editor/common/editor';
+import { ILifecycleService } from 'vs/platform/lifecycle/common/lifecycle';
+import { IOpenerService } from 'vs/platform/opener/common/opener';
+import { ExtHostContext, ExtHostWebviewsShape, IExtHostContext, MainContext, MainThreadWebviewsShape, WebviewHandle } from 'vs/workbench/api/node/extHost.protocol';
 import { WebviewEditor } from 'vs/workbench/parts/webview/electron-browser/webviewEditor';
-
+import { WebviewEditorInput } from 'vs/workbench/parts/webview/electron-browser/webviewInput';
+import { IWebviewService, WebviewInputOptions, WebviewReviver } from 'vs/workbench/parts/webview/electron-browser/webviewService';
+import { IWorkbenchEditorService } from 'vs/workbench/services/editor/common/editorService';
+import { IExtensionService } from 'vs/workbench/services/extensions/common/extensions';
+import { IEditorGroupService } from 'vs/workbench/services/group/common/groupService';
+import { extHostNamedCustomer } from './extHostCustomers';
 
 @extHostNamedCustomer(MainContext.MainThreadWebviews)
-export class MainThreadWebviews implements MainThreadWebviewsShape {
+export class MainThreadWebviews implements MainThreadWebviewsShape, WebviewReviver {
+
+	private static readonly viewType = 'mainThreadWebview';
+
 	private static readonly standardSupportedLinkSchemes = ['http', 'https', 'mailto'];
 
-	private _toDispose: Disposable[] = [];
+	private static revivalPool = 0;
+
+	private _toDispose: IDisposable[] = [];
 
 	private readonly _proxy: ExtHostWebviewsShape;
-	private readonly _webviews = new Map<WebviewHandle, WebviewInput>();
+	private readonly _webviews = new Map<WebviewHandle, WebviewEditorInput>();
+	private readonly _revivers = new Set<string>();
 
-	private _activeWebview: WebviewInput | undefined = undefined;
+	private _activeWebview: WebviewEditorInput | undefined = undefined;
 
 	constructor(
 		context: IExtHostContext,
-		@IContextKeyService _contextKeyService: IContextKeyService,
+		@IContextKeyService contextKeyService: IContextKeyService,
-		@IPartService private readonly _partService: IPartService,
+		@IEditorGroupService editorGroupService: IEditorGroupService,
+		@ILifecycleService lifecycleService: ILifecycleService,
 		@IWorkbenchEditorService private readonly _editorService: IWorkbenchEditorService,
-		@IEditorGroupService private readonly _editorGroupService: IEditorGroupService,
+		@IWebviewService private readonly _webviewService: IWebviewService,
-		@IOpenerService private readonly _openerService: IOpenerService
+		@IOpenerService private readonly _openerService: IOpenerService,
+		@IExtensionService private readonly _extensionService: IExtensionService,
+
 	) {
 		this._proxy = context.getProxy(ExtHostContext.ExtHostWebviews);
-		_editorGroupService.onEditorsChanged(this.onEditorsChanged, this, this._toDispose);
+		editorGroupService.onEditorsChanged(this.onEditorsChanged, this, this._toDispose);
+
+		_webviewService.registerReviver(MainThreadWebviews.viewType, this);
+		this._toDispose.push(lifecycleService.onWillShutdown(e => {
+			e.veto(this._onWillShutdown());
+		}));
 	}
 
 	dispose(): void {
@@ -51,30 +65,31 @@ export class MainThreadWebviews implements MainThreadWebviewsShape {
 		viewType: string,
 		title: string,
 		column: Position,
-		options: vscode.WebviewOptions,
+		options: WebviewInputOptions,
 		extensionFolderPath: string
 	): void {
-		const webviewInput = new WebviewInput(title, options, '', {
+		const webview = this._webviewService.createWebview(MainThreadWebviews.viewType, title, column, options, extensionFolderPath, {
+			onDidClickLink: uri => this.onDidClickLink(uri, webview.options),
 			onMessage: message => this._proxy.$onMessage(handle, message),
 			onDidChangePosition: position => this._proxy.$onDidChangePosition(handle, position),
 			onDispose: () => {
 				this._proxy.$onDidDisposeWeview(handle).then(() => {
 					this._webviews.delete(handle);
 				});
-			},
+			}
-			onDidClickLink: (link, options) => this.onDidClickLink(link, options)
+		});
-		}, this._partService);
 
-		this._webviews.set(handle, webviewInput);
+		webview.state = {
+			viewType: viewType,
+			state: undefined
+		};
 
-		this._editorService.openEditor(webviewInput, { pinned: true }, column);
+		this._webviews.set(handle, webview);
 	}
 
 	$disposeWebview(handle: WebviewHandle): void {
 		const webview = this.getWebview(handle);
-		if (webview) {
+		webview.dispose();
-			this._editorService.closeEditor(webview.position, webview);
-		}
 	}
 
 	$setTitle(handle: WebviewHandle, value: string): void {
@@ -84,24 +99,20 @@ export class MainThreadWebviews implements MainThreadWebviewsShape {
 
 	$setHtml(handle: WebviewHandle, value: string): void {
 		const webview = this.getWebview(handle);
-		webview.setHtml(value);
+		webview.html = value;
 	}
 
 	$reveal(handle: WebviewHandle, column: Position): void {
-		const webviewInput = this.getWebview(handle);
+		const webview = this.getWebview(handle);
-		if (webviewInput.position === column) {
+		this._webviewService.revealWebview(webview, column);
-			this._editorService.openEditor(webviewInput, { preserveFocus: true }, column);
-		} else {
-			this._editorGroupService.moveEditor(webviewInput, webviewInput.position, column, { preserveFocus: true });
-		}
 	}
 
 	async $sendMessage(handle: WebviewHandle, message: any): Promise<boolean> {
-		const webviewInput = this.getWebview(handle);
+		const webview = this.getWebview(handle);
 		const editors = this._editorService.getVisibleEditors()
 			.filter(e => e instanceof WebviewEditor)
 			.map(e => e as WebviewEditor)
-			.filter(e => e.input.matches(webviewInput));
+			.filter(e => e.input.matches(webview));
 
 		for (const editor of editors) {
 			editor.sendMessage(message);
@@ -110,18 +121,74 @@ export class MainThreadWebviews implements MainThreadWebviewsShape {
 		return (editors.length > 0);
 	}
 
-	private getWebview(handle: number): WebviewInput {
+	$registerSerializer(viewType: string): void {
-		const webviewInput = this._webviews.get(handle);
+		this._revivers.add(viewType);
-		if (!webviewInput) {
+	}
+
+	$unregisterSerializer(viewType: string): void {
+		this._revivers.delete(viewType);
+	}
+
+	reviveWebview(webview: WebviewEditorInput) {
+		this._extensionService.activateByEvent(`onView:${webview.state.viewType}`).then(() => {
+			const handle = 'revival-' + MainThreadWebviews.revivalPool++;
+			this._webviews.set(handle, webview);
+
+			webview._events = {
+				onDidClickLink: uri => this.onDidClickLink(uri, webview.options),
+				onMessage: message => this._proxy.$onMessage(handle, message),
+				onDidChangePosition: position => this._proxy.$onDidChangePosition(handle, position),
+				onDispose: () => {
+					this._proxy.$onDidDisposeWeview(handle).then(() => {
+						this._webviews.delete(handle);
+					});
+				}
+			};
+
+			this._proxy.$deserializeWebview(handle, webview.state.viewType, webview.state.state, webview.position, webview.options);
+		});
+	}
+
+	canRevive(webview: WebviewEditorInput): boolean {
+		return this._revivers.has(webview.viewType) || webview.reviver !== null;
+	}
+
+	private _onWillShutdown(): TPromise<boolean> {
+		const toRevive: WebviewHandle[] = [];
+		this._webviews.forEach((view, key) => {
+			if (this.canRevive(view)) {
+				toRevive.push(key);
+			}
+		});
+
+		const reviveResponses = toRevive.map(handle =>
+			this._proxy.$serializeWebview(handle).then(state => ({ handle, state })));
+
+		return TPromise.join(reviveResponses).then(results => {
+			for (const result of results) {
+				if (result.state) {
+					const view = this._webviews.get(result.handle);
+					if (view) {
+						view.state.state = result.state;
+					}
+				}
+			}
+			return false; // Don't veto shutdown
+		});
+	}
+
+	private getWebview(handle: WebviewHandle): WebviewEditorInput {
+		const webview = this._webviews.get(handle);
+		if (!webview) {
 			throw new Error('Unknown webview handle:' + handle);
 		}
-		return webviewInput;
+		return webview;
 	}
 
 	private onEditorsChanged() {
 		const activeEditor = this._editorService.getActiveEditor();
-		let newActiveWebview: { input: WebviewInput, handle: WebviewHandle } | undefined = undefined;
+		let newActiveWebview: { input: WebviewEditorInput, handle: WebviewHandle } | undefined = undefined;
-		if (activeEditor && activeEditor.input instanceof WebviewInput) {
+		if (activeEditor && activeEditor.input instanceof WebviewEditorInput) {
 			for (const handle of map.keys(this._webviews)) {
 				const input = this._webviews.get(handle);
 				if (input.matches(activeEditor.input)) {
@@ -132,7 +199,7 @@ export class MainThreadWebviews implements MainThreadWebviewsShape {
 		}
 
 		if (newActiveWebview) {
-			if (!this._activeWebview || !newActiveWebview.input.matches(this._activeWebview)) {
+			if (!this._activeWebview || newActiveWebview.input !== this._activeWebview) {
 				this._proxy.$onDidChangeActiveWeview(newActiveWebview.handle);
 				this._activeWebview = newActiveWebview.input;
 			}
@@ -144,7 +211,7 @@ export class MainThreadWebviews implements MainThreadWebviewsShape {
 		}
 	}
 
-	private onDidClickLink(link: URI, options: vscode.WebviewOptions): void {
+	private onDidClickLink(link: URI, options: WebviewInputOptions): void {
 		if (!link) {
 			return;
 		}

src/vs/workbench/api/node/extHost.api.impl.ts

@@ -418,6 +418,9 @@ export function createApiFactory(
 			}),
 			createWebview: proposedApiFunction(extension, (viewType: string, title: string, column: vscode.ViewColumn, options: vscode.WebviewOptions) => {
 				return extHostWebviews.createWebview(viewType, title, column, options, extension.extensionFolderPath);
+			}),
+			registerWebviewSerializer: proposedApiFunction(extension, (viewType: string, serializer: vscode.WebviewSerializer) => {
+				return extHostWebviews.registerWebviewSerializer(viewType, serializer);
 			})
 		};
 

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

@@ -347,7 +347,7 @@ export interface MainThreadTelemetryShape extends IDisposable {
 	$publicLog(eventName: string, data?: any): void;
 }
 
-export type WebviewHandle = number;
+export type WebviewHandle = string;
 
 export interface MainThreadWebviewsShape extends IDisposable {
 	$createWebview(handle: WebviewHandle, viewType: string, title: string, column: EditorPosition, options: vscode.WebviewOptions, extensionFolderPath: string): void;
@@ -356,12 +356,18 @@ export interface MainThreadWebviewsShape extends IDisposable {
 	$setTitle(handle: WebviewHandle, value: string): void;
 	$setHtml(handle: WebviewHandle, value: string): void;
 	$sendMessage(handle: WebviewHandle, value: any): Thenable<boolean>;
+
+	$registerSerializer(viewType: string): void;
+	$unregisterSerializer(viewType: string): void;
 }
+
 export interface ExtHostWebviewsShape {
 	$onMessage(handle: WebviewHandle, message: any): void;
 	$onDidChangeActiveWeview(handle: WebviewHandle | undefined): void;
 	$onDidDisposeWeview(handle: WebviewHandle): Thenable<void>;
 	$onDidChangePosition(handle: WebviewHandle, newPosition: EditorPosition): void;
+	$deserializeWebview(newWebviewHandle: WebviewHandle, viewType: string, state: any, position: EditorPosition, options: vscode.WebviewOptions): void;
+	$serializeWebview(webviewHandle: WebviewHandle): Thenable<any>;
 }
 
 export interface MainThreadWorkspaceShape extends IDisposable {

src/vs/workbench/api/node/extHostWebview.ts

@@ -9,6 +9,7 @@ import { Event, Emitter } from 'vs/base/common/event';
 import * as typeConverters from 'vs/workbench/api/node/extHostTypeConverters';
 import { Position } from 'vs/platform/editor/common/editor';
 import { TPromise } from 'vs/base/common/winjs.base';
+import { Disposable } from './extHostTypes';
 
 export class ExtHostWebview implements vscode.Webview {
 
@@ -19,6 +20,7 @@ export class ExtHostWebview implements vscode.Webview {
 	private _isDisposed: boolean = false;
 	private _viewColumn: vscode.ViewColumn;
 	private _active: boolean;
+	private _state: any;
 
 	public readonly onMessageEmitter = new Emitter<any>();
 	public readonly onDidReceiveMessage: Event<any> = this.onMessageEmitter.event;
@@ -85,6 +87,11 @@ export class ExtHostWebview implements vscode.Webview {
 		}
 	}
 
+	get state(): any {
+		this.assertNotDisposed();
+		return this._state;
+	}
+
 	get options(): vscode.WebviewOptions {
 		this.assertNotDisposed();
 		return this._options;
@@ -128,11 +135,12 @@ export class ExtHostWebview implements vscode.Webview {
 }
 
 export class ExtHostWebviews implements ExtHostWebviewsShape {
-	private static handlePool = 1;
+	private static webviewHandlePool = 1;
 
 	private readonly _proxy: MainThreadWebviewsShape;
 
 	private readonly _webviews = new Map<WebviewHandle, ExtHostWebview>();
+	private readonly _serializers = new Map<string, vscode.WebviewSerializer>();
 
 	private _activeWebview: ExtHostWebview | undefined;
 
@@ -149,7 +157,7 @@ export class ExtHostWebviews implements ExtHostWebviewsShape {
 		options: vscode.WebviewOptions,
 		extensionFolderPath: string
 	): vscode.Webview {
-		const handle = ExtHostWebviews.handlePool++;
+		const handle = ExtHostWebviews.webviewHandlePool++ + '';
 		this._proxy.$createWebview(handle, viewType, title, typeConverters.fromViewColumn(viewColumn), options, extensionFolderPath);
 
 		const webview = new ExtHostWebview(handle, this._proxy, viewType, viewColumn, options);
@@ -157,6 +165,23 @@ export class ExtHostWebviews implements ExtHostWebviewsShape {
 		return webview;
 	}
 
+	registerWebviewSerializer(
+		viewType: string,
+		serializer: vscode.WebviewSerializer
+	): vscode.Disposable {
+		if (this._serializers.has(viewType)) {
+			throw new Error(`Serializer for '${viewType}' already registered`);
+		}
+
+		this._serializers.set(viewType, serializer);
+		this._proxy.$registerSerializer(viewType);
+
+		return new Disposable(() => {
+			this._serializers.delete(viewType);
+			this._proxy.$unregisterSerializer(viewType);
+		});
+	}
+
 	$onMessage(handle: WebviewHandle, message: any): void {
 		const webview = this.getWebview(handle);
 		if (webview) {
@@ -206,8 +231,35 @@ export class ExtHostWebviews implements ExtHostWebviewsShape {
 		}
 	}
 
-	private readonly _onDidChangeActiveWebview = new Emitter<ExtHostWebview | undefined>();
+	$deserializeWebview(
-	public readonly onDidChangeActiveWebview = this._onDidChangeActiveWebview.event;
+		webviewHandle: WebviewHandle,
+		viewType: string,
+		state: any,
+		position: Position,
+		options: vscode.WebviewOptions
+	): void {
+		const serializer = this._serializers.get(viewType);
+		if (!serializer) {
+			return;
+		}
+
+		const revivedWebview = new ExtHostWebview(webviewHandle, this._proxy, viewType, typeConverters.toViewColumn(position), options);
+		this._webviews.set(webviewHandle, revivedWebview);
+		serializer.deserializeWebview(revivedWebview, state);
+	}
+
+	$serializeWebview(
+		webviewHandle: WebviewHandle
+	): Thenable<any> {
+		const webview = this.getWebview(webviewHandle);
+
+		const serialzer = this._serializers.get(webview.viewType);
+		if (!serialzer) {
+			return TPromise.as(undefined);
+		}
+
+		return serialzer.serializeWebview(webview);
+	}
 
 	private getWebview(handle: WebviewHandle) {
 		return this._webviews.get(handle);

src/vs/workbench/parts/update/electron-browser/releaseNotesEditor.ts

@@ -5,29 +5,29 @@
 
 'use strict';
 
-import { TPromise } from 'vs/base/common/winjs.base';
+import { onUnexpectedError } from 'vs/base/common/errors';
 import { marked } from 'vs/base/common/marked/marked';
-import { IModeService } from 'vs/editor/common/services/modeService';
+import { OS } from 'vs/base/common/platform';
-import { tokenizeToString } from 'vs/editor/common/modes/textToHtmlTokenizer';
+import URI from 'vs/base/common/uri';
+import { TPromise } from 'vs/base/common/winjs.base';
+import { asText } from 'vs/base/node/request';
 import { IMode, TokenizationRegistry } from 'vs/editor/common/modes';
 import { generateTokensCSSForColorMap } from 'vs/editor/common/modes/supports/tokenization';
-import { IWorkbenchEditorService } from 'vs/workbench/services/editor/common/editorService';
+import { tokenizeToString } from 'vs/editor/common/modes/textToHtmlTokenizer';
-import { ServicesAccessor } from 'vs/platform/instantiation/common/instantiation';
+import { IModeService } from 'vs/editor/common/services/modeService';
-import { KeybindingIO } from 'vs/workbench/services/keybinding/common/keybindingIO';
-import { IKeybindingService } from 'vs/platform/keybinding/common/keybinding';
-import { IRequestService } from 'vs/platform/request/node/request';
-import { IEnvironmentService } from 'vs/platform/environment/common/environment';
-import { IPartService } from 'vs/workbench/services/part/common/partService';
-import { IOpenerService } from 'vs/platform/opener/common/opener';
-import { ITelemetryService } from 'vs/platform/telemetry/common/telemetry';
-import { WebviewInput } from 'vs/workbench/parts/webview/electron-browser/webviewInput';
-import { onUnexpectedError } from 'vs/base/common/errors';
-import { addGAParameters } from 'vs/platform/telemetry/node/telemetryNodeUtils';
-import URI from 'vs/base/common/uri';
-import { asText } from 'vs/base/node/request';
 import * as nls from 'vs/nls';
-import { OS } from 'vs/base/common/platform';
+import { IEnvironmentService } from 'vs/platform/environment/common/environment';
-import { IEditorGroupService } from 'vs/workbench/services/group/common/groupService';
+import { ServicesAccessor } from 'vs/platform/instantiation/common/instantiation';
+import { IKeybindingService } from 'vs/platform/keybinding/common/keybinding';
+import { IOpenerService } from 'vs/platform/opener/common/opener';
+import { IRequestService } from 'vs/platform/request/node/request';
+import { ITelemetryService } from 'vs/platform/telemetry/common/telemetry';
+import { addGAParameters } from 'vs/platform/telemetry/node/telemetryNodeUtils';
+import { IWebviewService } from 'vs/workbench/parts/webview/electron-browser/webviewService';
+import { IWorkbenchEditorService } from 'vs/workbench/services/editor/common/editorService';
+import { KeybindingIO } from 'vs/workbench/services/keybinding/common/keybindingIO';
+import { Position } from 'vs/platform/editor/common/editor';
+import { WebviewEditorInput } from 'vs/workbench/parts/webview/electron-browser/webviewInput';
 
 function renderBody(
 	body: string,
@@ -51,18 +51,17 @@ export class ReleaseNotesManager {
 
 	private _releaseNotesCache: { [version: string]: TPromise<string>; } = Object.create(null);
 
-	private _currentReleaseNotes: WebviewInput | undefined = undefined;
+	private _currentReleaseNotes: WebviewEditorInput | undefined = undefined;
 
 	public constructor(
-		@IEditorGroupService private readonly _editorGroupService: IEditorGroupService,
 		@IEnvironmentService private readonly _environmentService: IEnvironmentService,
 		@IKeybindingService private readonly _keybindingService: IKeybindingService,
 		@IModeService private readonly _modeService: IModeService,
 		@IOpenerService private readonly _openerService: IOpenerService,
-		@IPartService private readonly _partService: IPartService,
 		@IRequestService private readonly _requestService: IRequestService,
 		@ITelemetryService private readonly _telemetryService: ITelemetryService,
 		@IWorkbenchEditorService private readonly _editorService: IWorkbenchEditorService,
+		@IWebviewService private readonly _webviewService: IWebviewService,
 	) { }
 
 	public async show(
@@ -73,21 +72,23 @@ export class ReleaseNotesManager {
 		const html = await this.renderBody(releaseNoteText);
 		const title = nls.localize('releaseNotesInputName', "Release Notes: {0}", version);
 
+		const activeEditor = this._editorService.getActiveEditor();
 		if (this._currentReleaseNotes) {
 			this._currentReleaseNotes.setName(title);
-			this._currentReleaseNotes.setHtml(html);
+			this._currentReleaseNotes.html = html;
-			const activeEditor = this._editorService.getActiveEditor();
+			this._webviewService.revealWebview(this._currentReleaseNotes, activeEditor ? activeEditor.position : undefined);
-			if (activeEditor && activeEditor.position !== this._currentReleaseNotes.position) {
-				this._editorGroupService.moveEditor(this._currentReleaseNotes, this._currentReleaseNotes.position, activeEditor.position, { preserveFocus: true });
-			} else {
-				this._editorService.openEditor(this._currentReleaseNotes, { preserveFocus: true });
-			}
 		} else {
-			this._currentReleaseNotes = new WebviewInput(title, { tryRestoreScrollPosition: true, enableFindWidget: true }, html, {
+			this._currentReleaseNotes = this._webviewService.createWebview(
-				onDidClickLink: uri => this.onDidClickLink(uri),
+				'releaseNotes',
-				onDispose: () => { this._currentReleaseNotes = undefined; }
+				title,
-			}, this._partService);
+				activeEditor ? activeEditor.position : Position.ONE,
-			await this._editorService.openEditor(this._currentReleaseNotes, { pinned: true });
+				{ tryRestoreScrollPosition: true, enableFindWidget: true },
+				undefined, {
+					onDidClickLink: uri => this.onDidClickLink(uri),
+					onDispose: () => { this._currentReleaseNotes = undefined; }
+				});
+
+			this._currentReleaseNotes.html = html;
 		}
 
 		return true;

src/vs/workbench/parts/webview/electron-browser/webview.contribution.ts

@@ -7,11 +7,21 @@ import { IEditorRegistry, EditorDescriptor, Extensions as EditorExtensions } fro
 import { WebviewEditor } from './webviewEditor';
 import { SyncDescriptor } from 'vs/platform/instantiation/common/descriptors';
 import { Registry } from 'vs/platform/registry/common/platform';
-import { WebviewInput } from './webviewInput';
+import { WebviewEditorInput } from './webviewInput';
 import { localize } from 'vs/nls';
+import { IEditorInputFactoryRegistry, Extensions as EditorInputExtensions } from 'vs/workbench/common/editor';
+import { registerSingleton } from 'vs/platform/instantiation/common/extensions';
+import { IWebviewService, WebviewService } from './webviewService';
+import { WebviewInputFactory } from 'vs/workbench/parts/webview/electron-browser/webviewInputFactory';
 
 (Registry.as<IEditorRegistry>(EditorExtensions.Editors)).registerEditor(new EditorDescriptor(
 	WebviewEditor,
 	WebviewEditor.ID,
 	localize('webview.editor.label', "webview editor")),
-	[new SyncDescriptor(WebviewInput)]);
+	[new SyncDescriptor(WebviewEditorInput)]);
+
+Registry.as<IEditorInputFactoryRegistry>(EditorInputExtensions.EditorInputFactories).registerEditorInputFactory(
+	WebviewInputFactory.ID,
+	WebviewInputFactory);
+
+registerSingleton(IWebviewService, WebviewService);

src/vs/workbench/parts/webview/electron-browser/webviewEditor.ts

@@ -19,7 +19,7 @@ import { IEnvironmentService } from 'vs/platform/environment/common/environment'
 import { IWorkspaceContextService } from 'vs/platform/workspace/common/workspace';
 import * as DOM from 'vs/base/browser/dom';
 import { Event, Emitter } from 'vs/base/common/event';
-import { WebviewInput } from 'vs/workbench/parts/webview/electron-browser/webviewInput';
+import { WebviewEditorInput } from 'vs/workbench/parts/webview/electron-browser/webviewInput';
 import URI from 'vs/base/common/uri';
 
 export class WebviewEditor extends BaseWebviewEditor {
@@ -29,10 +29,12 @@ export class WebviewEditor extends BaseWebviewEditor {
 	private editorFrame: HTMLElement;
 	private content: HTMLElement;
 	private webviewContent: HTMLElement | undefined;
-	private readonly _onDidFocusWebview: Emitter<void>;
+
 	private _webviewFocusTracker?: DOM.IFocusTracker;
 	private _webviewFocusListenerDisposable?: IDisposable;
 
+	private readonly _onDidFocusWebview = new Emitter<void>();
+
 	constructor(
 		@ITelemetryService telemetryService: ITelemetryService,
 		@IThemeService themeService: IThemeService,
@@ -43,8 +45,6 @@ export class WebviewEditor extends BaseWebviewEditor {
 		@IWorkspaceContextService private readonly _contextService: IWorkspaceContextService
 	) {
 		super(WebviewEditor.ID, telemetryService, themeService, _contextKeyService);
-
-		this._onDidFocusWebview = new Emitter<void>();
 	}
 
 	protected createEditor(parent: Builder): void {
@@ -54,7 +54,7 @@ export class WebviewEditor extends BaseWebviewEditor {
 	}
 
 	private doUpdateContainer() {
-		const webviewContainer = this.input && (this.input as WebviewInput).container;
+		const webviewContainer = this.input && (this.input as WebviewEditorInput).container;
 		if (webviewContainer && webviewContainer.parentElement) {
 			const frameRect = this.editorFrame.getBoundingClientRect();
 			const containerRect = webviewContainer.parentElement.getBoundingClientRect();
@@ -103,14 +103,14 @@ export class WebviewEditor extends BaseWebviewEditor {
 	}
 
 	protected setEditorVisible(visible: boolean, position?: Position): void {
-		if (this.input && this.input instanceof WebviewInput) {
+		if (this.input && this.input instanceof WebviewEditorInput) {
 			if (visible) {
 				this.input.claimWebview(this);
 			} else {
 				this.input.releaseWebview(this);
 			}
 
-			this.updateWebview(this.input as WebviewInput);
+			this.updateWebview(this.input as WebviewEditorInput);
 		}
 
 		if (this.webviewContent) {
@@ -126,7 +126,7 @@ export class WebviewEditor extends BaseWebviewEditor {
 	}
 
 	public clearInput() {
-		if (this.input && this.input instanceof WebviewInput) {
+		if (this.input && this.input instanceof WebviewEditorInput) {
 			this.input.releaseWebview(this);
 		}
 
@@ -136,24 +136,24 @@ export class WebviewEditor extends BaseWebviewEditor {
 		super.clearInput();
 	}
 
-	async setInput(input: WebviewInput, options: EditorOptions): TPromise<void> {
+	async setInput(input: WebviewEditorInput, options: EditorOptions): TPromise<void> {
 		if (this.input && this.input.matches(input)) {
 			return undefined;
 		}
 
 		if (this.input) {
-			(this.input as WebviewInput).releaseWebview(this);
+			(this.input as WebviewEditorInput).releaseWebview(this);
 			this._webview = undefined;
 			this.webviewContent = undefined;
 		}
 
 		await super.setInput(input, options);
 
-		input.onDidChangePosition(this.position);
+		input.onBecameActive(this.position);
 		this.updateWebview(input);
 	}
 
-	private updateWebview(input: WebviewInput) {
+	private updateWebview(input: WebviewEditorInput) {
 		const webview = this.getWebview(input);
 		input.claimWebview(this);
 		webview.options = {
@@ -163,7 +163,7 @@ export class WebviewEditor extends BaseWebviewEditor {
 			useSameOriginForRoot: false,
 			localResourceRoots: input.options.localResourceRoots || this.getDefaultLocalResourceRoots()
 		};
-		input.setHtml(input.html);
+		input.html = input.html;
 
 		if (this.webviewContent) {
 			this.webviewContent.style.visibility = 'visible';
@@ -174,13 +174,13 @@ export class WebviewEditor extends BaseWebviewEditor {
 
 	private getDefaultLocalResourceRoots(): URI[] {
 		const rootPaths = this._contextService.getWorkspace().folders.map(x => x.uri);
-		if ((this.input as WebviewInput).extensionFolderPath) {
+		if ((this.input as WebviewEditorInput).extensionFolderPath) {
-			rootPaths.push((this.input as WebviewInput).extensionFolderPath);
+			rootPaths.push((this.input as WebviewEditorInput).extensionFolderPath);
 		}
 		return rootPaths;
 	}
 
-	private getWebview(input: WebviewInput): Webview {
+	private getWebview(input: WebviewEditorInput): Webview {
 		if (this._webview) {
 			return this._webview;
 		}

src/vs/workbench/parts/webview/electron-browser/webviewInput.ts

@@ -5,69 +5,61 @@
 
 'use strict';
 
-import { TPromise } from 'vs/base/common/winjs.base';
 import { IDisposable, dispose } from 'vs/base/common/lifecycle';
+import URI from 'vs/base/common/uri';
+import { TPromise } from 'vs/base/common/winjs.base';
+import { IEditorInput, IEditorModel, Position } from 'vs/platform/editor/common/editor';
 import { EditorInput, EditorModel } from 'vs/workbench/common/editor';
-import { IEditorModel, Position, IEditorInput } from 'vs/platform/editor/common/editor';
 import { Webview } from 'vs/workbench/parts/html/electron-browser/webview';
 import { IPartService, Parts } from 'vs/workbench/services/part/common/partService';
-import * as vscode from 'vscode';
+import { WebviewEvents, WebviewInputOptions, WebviewReviver } from './webviewService';
-import URI from 'vs/base/common/uri';
 
-export interface WebviewEvents {
-	onMessage?(message: any): void;
-	onDidChangePosition?(newPosition: Position): void;
-	onDispose?(): void;
-	onDidClickLink?(link: URI, options: vscode.WebviewOptions): void;
-}
 
-export interface WebviewInputOptions extends vscode.WebviewOptions {
+export class WebviewEditorInput extends EditorInput {
-	tryRestoreScrollPosition?: boolean;
-}
-
-export class WebviewInput extends EditorInput {
 	private static handlePool = 0;
 
+	public static readonly typeId = 'workbench.editors.webviewInput';
+
 	private _name: string;
 	private _options: WebviewInputOptions;
-	private _html: string;
+	private _html: string = '';
 	private _currentWebviewHtml: string = '';
-	private _events: WebviewEvents | undefined;
+	public _events: WebviewEvents | undefined;
 	private _container: HTMLElement;
 	private _webview: Webview | undefined;
 	private _webviewOwner: any;
 	private _webviewDisposables: IDisposable[] = [];
 	private _position?: Position;
 	private _scrollYPercentage: number = 0;
+	private _state: any;
+
+	private _revived: boolean = false;
+
 	public readonly extensionFolderPath: URI | undefined;
 
 	constructor(
+		public readonly viewType: string,
 		name: string,
 		options: WebviewInputOptions,
-		html: string,
+		state: any,
 		events: WebviewEvents,
-		partService: IPartService,
+		extensionFolderPath: string | undefined,
-		extensionFolderPath?: string
+		public readonly reviver: WebviewReviver | undefined,
+		@IPartService private readonly _partService: IPartService,
 	) {
 		super();
 		this._name = name;
 		this._options = options;
-		this._html = html;
 		this._events = events;
+		this._state = state;
 
 		if (extensionFolderPath) {
 			this.extensionFolderPath = URI.file(extensionFolderPath);
 		}
-
-		const id = WebviewInput.handlePool++;
-		this._container = document.createElement('div');
-		this._container.id = `webview-${id}`;
-
-		partService.getContainer(Parts.EDITOR_PART).appendChild(this._container);
 	}
 
 	public getTypeId(): string {
-		return 'webview';
+		return WebviewEditorInput.typeId;
 	}
 
 	public dispose() {
@@ -119,7 +111,7 @@ export class WebviewInput extends EditorInput {
 		return this._html;
 	}
 
-	public setHtml(value: string): void {
+	public set html(value: string) {
 		if (value === this._currentWebviewHtml) {
 			return;
 		}
@@ -132,6 +124,14 @@ export class WebviewInput extends EditorInput {
 		}
 	}
 
+	public get state(): any {
+		return this._state;
+	}
+
+	public set state(value: any) {
+		this._state = value;
+	}
+
 	public get options(): WebviewInputOptions {
 		return this._options;
 	}
@@ -149,6 +149,12 @@ export class WebviewInput extends EditorInput {
 	}
 
 	public get container(): HTMLElement {
+		if (!this._container) {
+			const id = WebviewEditorInput.handlePool++;
+			this._container = document.createElement('div');
+			this._container.id = `webview-${id}`;
+			this._partService.getContainer(Parts.EDITOR_PART).appendChild(this._container);
+		}
 		return this._container;
 	}
 
@@ -215,10 +221,16 @@ export class WebviewInput extends EditorInput {
 		this._currentWebviewHtml = '';
 	}
 
-	public onDidChangePosition(position: Position) {
+	public onBecameActive(position: Position) {
+		this._position = position;
+
 		if (this._events && this._events.onDidChangePosition) {
 			this._events.onDidChangePosition(position);
 		}
-		this._position = position;
+
+		if (this.reviver && !this._revived) {
+			this._revived = true;
+			this.reviver.reviveWebview(this);
+		}
 	}
 }

src/vs/workbench/parts/webview/electron-browser/webviewInputFactory.ts

@@ -0,0 +1,54 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+'use strict';
+
+import { IInstantiationService } from 'vs/platform/instantiation/common/instantiation';
+import { IEditorInputFactory } from 'vs/workbench/common/editor';
+import { IWebviewService, WebviewInputOptions } from './webviewService';
+import { WebviewEditorInput } from './webviewInput';
+
+interface SerializedWebview {
+	readonly viewType: string;
+	readonly title: string;
+	readonly options: WebviewInputOptions;
+	readonly extensionFolderPath: string;
+	readonly state: any;
+}
+
+export class WebviewInputFactory implements IEditorInputFactory {
+
+	public static readonly ID = WebviewEditorInput.typeId;
+
+	public constructor(
+		@IWebviewService private readonly _webviewService: IWebviewService
+	) { }
+
+	public serialize(
+		input: WebviewEditorInput
+	): string {
+		// Only attempt revival if we may have a reviver
+		if (!this._webviewService.canRevive(input) && !input.reviver) {
+			return null;
+		}
+
+		const data: SerializedWebview = {
+			viewType: input.viewType,
+			title: input.getName(),
+			options: input.options,
+			extensionFolderPath: input.extensionFolderPath.fsPath,
+			state: input.state
+		};
+		return JSON.stringify(data);
+	}
+
+	public deserialize(
+		instantiationService: IInstantiationService,
+		serializedEditorInput: string
+	): WebviewEditorInput {
+		const data: SerializedWebview = JSON.parse(serializedEditorInput);
+		return this._webviewService.createRevivableWebview(data.viewType, data.title, data.state, data.options, data.extensionFolderPath);
+	}
+}

src/vs/workbench/parts/webview/electron-browser/webviewService.ts

@@ -0,0 +1,175 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+import { IDisposable, toDisposable } from 'vs/base/common/lifecycle';
+import URI from 'vs/base/common/uri';
+import { Position } from 'vs/platform/editor/common/editor';
+import { IInstantiationService, createDecorator } from 'vs/platform/instantiation/common/instantiation';
+import { IWorkbenchEditorService } from 'vs/workbench/services/editor/common/editorService';
+import { IEditorGroupService } from 'vs/workbench/services/group/common/groupService';
+import * as vscode from 'vscode';
+import { WebviewEditorInput } from './webviewInput';
+
+export const IWebviewService = createDecorator<IWebviewService>('webviewService');
+
+export interface IWebviewService {
+	_serviceBrand: any;
+
+	createWebview(
+		viewType: string,
+		title: string,
+		column: Position,
+		options: WebviewInputOptions,
+		extensionFolderPath: string,
+		events: WebviewEvents
+	): WebviewEditorInput;
+
+	createRevivableWebview(
+		viewType: string,
+		title: string,
+		state: any,
+		options: WebviewInputOptions,
+		extensionFolderPath: string
+	): WebviewEditorInput;
+
+	revealWebview(
+		webview: WebviewEditorInput,
+		column: Position | undefined
+	): void;
+
+	registerReviver(
+		viewType: string,
+		reviver: WebviewReviver
+	): IDisposable;
+
+	canRevive(
+		input: WebviewEditorInput
+	): boolean;
+}
+
+export interface WebviewReviver {
+	canRevive(
+		webview: WebviewEditorInput
+	): boolean;
+
+	reviveWebview(
+		webview: WebviewEditorInput
+	): void;
+}
+
+export interface WebviewEvents {
+	onMessage?(message: any): void;
+	onDidChangePosition?(newPosition: Position): void;
+	onDispose?(): void;
+	onDidClickLink?(link: URI, options: vscode.WebviewOptions): void;
+}
+
+export interface WebviewInputOptions extends vscode.WebviewOptions {
+	tryRestoreScrollPosition?: boolean;
+}
+
+export class WebviewService implements IWebviewService {
+	_serviceBrand: any;
+
+	private readonly _revivers = new Map<string, WebviewReviver>();
+	private readonly _needingRevival = new Map<string, WebviewEditorInput[]>();
+
+	constructor(
+		@IWorkbenchEditorService private readonly _editorService: IWorkbenchEditorService,
+		@IInstantiationService private readonly _instantiationService: IInstantiationService,
+		@IEditorGroupService private readonly _editorGroupService: IEditorGroupService,
+	) { }
+
+	createWebview(
+		viewType: string,
+		title: string,
+		column: Position,
+		options: vscode.WebviewOptions,
+		extensionFolderPath: string,
+		events: WebviewEvents
+	): WebviewEditorInput {
+		const webviewInput = this._instantiationService.createInstance(WebviewEditorInput, viewType, title, options, {}, events, extensionFolderPath, undefined);
+		this._editorService.openEditor(webviewInput, { pinned: true }, column);
+		return webviewInput;
+	}
+
+	revealWebview(
+		webview: WebviewEditorInput,
+		column: Position | undefined
+	): void {
+		if (typeof column === 'undefined') {
+			column = webview.position;
+		}
+
+		if (webview.position === column) {
+			this._editorService.openEditor(webview, { preserveFocus: true }, column);
+		} else {
+			this._editorGroupService.moveEditor(webview, webview.position, column, { preserveFocus: true });
+		}
+	}
+
+	createRevivableWebview(
+		viewType: string,
+		title: string,
+		state: any,
+		options: WebviewInputOptions,
+		extensionFolderPath: string
+	): WebviewEditorInput {
+		const webviewInput = this._instantiationService.createInstance(WebviewEditorInput, viewType, title, options, state, {}, extensionFolderPath, {
+			canRevive: (webview) => {
+				return true;
+			},
+			reviveWebview: (webview) => {
+				if (!this._needingRevival.has(viewType)) {
+					this._needingRevival.set(viewType, []);
+				}
+				this._needingRevival.get(viewType).push(webviewInput);
+				this.tryRevive(viewType);
+			}
+		});
+
+		return webviewInput;
+	}
+
+	registerReviver(
+		viewType: string,
+		reviver: WebviewReviver
+	): IDisposable {
+		if (this._revivers.has(viewType)) {
+			throw new Error(`Reveriver for 'viewType' already registered`);
+		}
+
+		this._revivers.set(viewType, reviver);
+		this.tryRevive(viewType);
+
+		return toDisposable(() => {
+			this._revivers.delete(viewType);
+		});
+	}
+
+	canRevive(
+		webview: WebviewEditorInput
+	): boolean {
+		const viewType = webview.viewType;
+		return this._revivers.has(viewType) && this._revivers.get(viewType).canRevive(webview);
+	}
+
+	tryRevive(
+		viewType: string
+	) {
+		const reviver = this._revivers.get(viewType);
+		if (!reviver) {
+			return;
+		}
+
+		const toRevive = this._needingRevival.get(viewType);
+		if (!toRevive) {
+			return;
+		}
+
+		for (const webview of toRevive) {
+			reviver.reviveWebview(webview);
+		}
+	}
+}