Switch webview api back to use delegate model

For #77131

Going back the the delegate based model for a few reasons:

- It gives us a better approach to add additional API hooks in the future (such as for rename)

- In practive, the capabilities were almost always the same as the `userData` on the document. It is rather confusing to have both `userData` and the capabilities 'on' the document

extensions/image-preview/src/preview.ts

@@ -27,8 +27,8 @@ export class PreviewManager implements vscode.CustomEditorProvider {
 		private readonly zoomStatusBarEntry: ZoomStatusBarEntry,
 	) { }
 
-	public async resolveCustomDocument(_document: vscode.CustomDocument): Promise<vscode.CustomEditorCapabilities> {
-		return {};
+	public async resolveCustomDocument(_document: vscode.CustomDocument): Promise<void> {
+		// noop
 	}
 
 	public async resolveCustomEditor(

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

@@ -148,8 +148,8 @@ export class MarkdownPreviewManager extends Disposable implements vscode.Webview
 		this.registerDynamicPreview(preview);
 	}
 
-	public async resolveCustomDocument(_document: vscode.CustomDocument): Promise<vscode.CustomEditorCapabilities> {
-		return {};
+	public async resolveCustomDocument(_document: vscode.CustomDocument): Promise<void> {
+		// noop
 	}
 
 	public async resolveCustomTextEditor(

src/vs/vscode.proposed.d.ts

@@ -1222,78 +1222,88 @@ declare module 'vscode' {
 	// - Should we expose edits?
 	// - More properties from `TextDocument`?
 
-	/**
-	 * Defines the capabilities of a custom webview editor.
-	 */
-	interface CustomEditorCapabilities {
-		/**
-		 * Defines the editing capability of a custom webview document.
-		 *
-		 * When not provided, the document is considered readonly.
-		 */
-		readonly editing?: CustomEditorEditingCapability;
-	}
-
 	/**
 	 * Defines the editing capability of a custom webview editor. This allows the webview editor to hook into standard
 	 * editor events such as `undo` or `save`.
 	 *
 	 * @param EditType Type of edits.
 	 */
-	interface CustomEditorEditingCapability<EditType = unknown> {
+	interface CustomEditorEditingDelegate<EditType = unknown> {
 		/**
 		 * Save the resource.
 		 *
+		 * @param document Document to save.
 		 * @param cancellation Token that signals the save is no longer required (for example, if another save was triggered).
 		 *
 		 * @return Thenable signaling that the save has completed.
 		 */
-		save(cancellation: CancellationToken): Thenable<void>;
+		save(document: CustomDocument, cancellation: CancellationToken): Thenable<void>;
 
 		/**
 		 * Save the existing resource at a new path.
 		 *
+		 * @param document Document to save.
 		 * @param targetResource Location to save to.
 		 *
 		 * @return Thenable signaling that the save has completed.
 		 */
-		saveAs(targetResource: Uri): Thenable<void>;
+		saveAs(document: CustomDocument, targetResource: Uri): Thenable<void>;
 
 		/**
 		 * Event triggered by extensions to signal to VS Code that an edit has occurred.
 		 */
-		readonly onDidEdit: Event<EditType>;
+		readonly onDidEdit: Event<{
+			/**
+			 * Document the edit is for.
+			 */
+			readonly document: CustomDocument;
+
+			/**
+			 * Object that describes the edit.
+			 *
+			 * Edit objects are passed back to your extension in `undoEdits`, `applyEdits`, and `revert`.
+			 */
+			readonly edit: EditType;
+
+			/**
+			 * Display name describing the edit.
+			 */
+			readonly label?: string;
+		}>;
 
 		/**
 		 * Apply a set of edits.
 		 *
 		 * Note that is not invoked when `onDidEdit` is called because `onDidEdit` implies also updating the view to reflect the edit.
 		 *
+		 * @param document Document to apply edits to.
 		 * @param edit Array of edits. Sorted from oldest to most recent.
 		 *
 		 * @return Thenable signaling that the change has completed.
 		 */
-		applyEdits(edits: readonly EditType[]): Thenable<void>;
+		applyEdits(document: CustomDocument, edits: readonly EditType[]): Thenable<void>;
 
 		/**
 		 * Undo a set of edits.
 		 *
 		 * This is triggered when a user undoes an edit.
 		 *
+		 * @param document Document to undo edits from.
 		 * @param edit Array of edits. Sorted from most recent to oldest.
 		 *
 		 * @return Thenable signaling that the change has completed.
 		 */
-		undoEdits(edits: readonly EditType[]): Thenable<void>;
+		undoEdits(document: CustomDocument, edits: readonly EditType[]): Thenable<void>;
 
 		/**
 		 * Revert the file to its last saved state.
 		 *
+		 * @param document Document to revert.
 		 * @param change Added or applied edits.
 		 *
 		 * @return Thenable signaling that the change has completed.
 		 */
-		revert(change: {
+		revert(document: CustomDocument, change: {
 			readonly undoneEdits: readonly EditType[];
 			readonly appliedEdits: readonly EditType[];
 		}): Thenable<void>;
@@ -1311,12 +1321,13 @@ declare module 'vscode' {
 		 * made in quick succession, `backup` is only triggered after the last one. `backup` is not invoked when
 		 * `auto save` is enabled (since auto save already persists resource ).
 		 *
+		 * @param document Document to revert.
 		 * @param cancellation Token that signals the current backup since a new backup is coming in. It is up to your
 		 * extension to decided how to respond to cancellation. If for example your extension is backing up a large file
 		 * in an operation that takes time to complete, your extension may decide to finish the ongoing backup rather
 		 * than cancelling it to ensure that VS Code has some valid backup.
 		 */
-		backup(cancellation: CancellationToken): Thenable<void>;
+		backup(document: CustomDocument, cancellation: CancellationToken): Thenable<void>;
 	}
 
 	/**
@@ -1375,7 +1386,7 @@ declare module 'vscode' {
 		 *
 		 * @return The capabilities of the resolved document.
 		 */
-		resolveCustomDocument(document: CustomDocument): Thenable<CustomEditorCapabilities>;
+		resolveCustomDocument(document: CustomDocument): Thenable<void>;
 
 		/**
 		 * Resolve a webview editor for a given resource.
@@ -1393,6 +1404,13 @@ declare module 'vscode' {
 		 * @return Thenable indicating that the webview editor has been resolved.
 		 */
 		resolveCustomEditor(document: CustomDocument, webviewPanel: WebviewPanel): Thenable<void>;
+
+		/**
+		 * Defines the editing capability of a custom webview document.
+		 *
+		 * When not provided, the document is considered readonly.
+		 */
+		readonly editingDelegate?: CustomEditorEditingDelegate;
 	}
 
 	/**

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

@@ -366,14 +366,14 @@ export class MainThreadWebviews extends Disposable implements extHostProtocol.Ma
 		return this._customEditorService.models.add(resource, viewType, model);
 	}
 
-	public async $onDidEdit(resourceComponents: UriComponents, viewType: string, editId: number): Promise<void> {
+	public async $onDidEdit(resourceComponents: UriComponents, viewType: string, editId: number, label: string | undefined): Promise<void> {
 		const resource = URI.revive(resourceComponents);
 		const model = await this._customEditorService.models.get(resource, viewType);
 		if (!model || !(model instanceof MainThreadCustomEditorModel)) {
 			throw new Error('Could not find model for webview editor');
 		}
 
-		model.pushEdit(editId);
+		model.pushEdit(editId, label);
 	}
 
 	private hookupWebviewEventDelegate(handle: extHostProtocol.WebviewPanelHandle, input: WebviewInput) {
@@ -604,7 +604,7 @@ class MainThreadCustomEditorModel extends Disposable implements ICustomEditorMod
 		return this._viewType;
 	}
 
-	public pushEdit(editId: number) {
+	public pushEdit(editId: number, label: string | undefined) {
 		if (!this._editable) {
 			throw new Error('Document is not editable');
 		}
@@ -617,7 +617,7 @@ class MainThreadCustomEditorModel extends Disposable implements ICustomEditorMod
 		this._undoService.pushElement({
 			type: UndoRedoElementType.Resource,
 			resource: this.resource,
-			label: 'Edit', // TODO: get this from extensions?
+			label: label ?? 'Edit',
 			undo: async () => {
 				if (!this._editable) {
 					return;

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

@@ -592,7 +592,7 @@ export interface MainThreadWebviewsShape extends IDisposable {
 	$registerCustomEditorProvider(extension: WebviewExtensionDescription, viewType: string, options: modes.IWebviewPanelOptions): void;
 	$unregisterEditorProvider(viewType: string): void;
 
-	$onDidEdit(resource: UriComponents, viewType: string, editId: number): void;
+	$onDidEdit(resource: UriComponents, viewType: string, editId: number, label: string | undefined): void;
 }
 
 export interface WebviewPanelViewStateData {

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

@@ -5,7 +5,7 @@
 
 import { CancellationToken } from 'vs/base/common/cancellation';
 import { Emitter, Event } from 'vs/base/common/event';
-import { Disposable } from 'vs/base/common/lifecycle';
+import { Disposable, DisposableStore } from 'vs/base/common/lifecycle';
 import { URI, UriComponents } from 'vs/base/common/uri';
 import { generateUuid } from 'vs/base/common/uuid';
 import * as modes from 'vs/editor/common/modes';
@@ -248,25 +248,31 @@ export class ExtHostWebviewEditor extends Disposable implements vscode.WebviewPa
 
 class CustomDocument extends Disposable implements vscode.CustomDocument {
 
-	public static create(proxy: MainThreadWebviewsShape, viewType: string, uri: vscode.Uri) {
-		return Object.seal(new CustomDocument(proxy, viewType, uri));
+	public static create(
+		viewType: string,
+		uri: vscode.Uri,
+		editingDelegate: vscode.CustomEditorEditingDelegate | undefined
+	) {
+		return Object.seal(new CustomDocument(viewType, uri, editingDelegate));
 	}
 
 	// Explicitly initialize all properties as we seal the object after creation!
 
 	readonly #_edits = new Cache<unknown>('edits');
 
-	readonly #proxy: MainThreadWebviewsShape;
 	readonly #viewType: string;
 	readonly #uri: vscode.Uri;
+	readonly #editingDelegate: vscode.CustomEditorEditingDelegate | undefined;
 
-	#capabilities: vscode.CustomEditorCapabilities | undefined = undefined;
-
-	private constructor(proxy: MainThreadWebviewsShape, viewType: string, uri: vscode.Uri) {
+	private constructor(
+		viewType: string,
+		uri: vscode.Uri,
+		editingDelegate: vscode.CustomEditorEditingDelegate | undefined,
+	) {
 		super();
-		this.#proxy = proxy;
 		this.#viewType = viewType;
 		this.#uri = uri;
+		this.#editingDelegate = editingDelegate;
 	}
 
 	dispose() {
@@ -289,47 +295,35 @@ class CustomDocument extends Disposable implements vscode.CustomDocument {
 
 	//#region Internal
 
-	/** @internal*/ _setCapabilities(capabilities: vscode.CustomEditorCapabilities) {
-		if (this.#capabilities) {
-			throw new Error('Capabilities already provided');
-		}
-
-		this.#capabilities = capabilities;
-		capabilities.editing?.onDidEdit(edit => {
-			const id = this.#_edits.add([edit]);
-			this.#proxy.$onDidEdit(this.uri, this.viewType, id);
-		});
-	}
-
 	/** @internal*/ async _revert(changes: { undoneEdits: number[], redoneEdits: number[] }) {
-		const editing = this.getEditingCapability();
+		const editing = this.getEditingDelegate();
 		const undoneEdits = changes.undoneEdits.map(id => this.#_edits.get(id, 0));
 		const appliedEdits = changes.redoneEdits.map(id => this.#_edits.get(id, 0));
-		return editing.revert({ undoneEdits, appliedEdits });
+		return editing.revert(this, { undoneEdits, appliedEdits });
 	}
 
 	/** @internal*/ _undo(editId: number) {
-		const editing = this.getEditingCapability();
+		const editing = this.getEditingDelegate();
 		const edit = this.#_edits.get(editId, 0);
-		return editing.undoEdits([edit]);
+		return editing.undoEdits(this, [edit]);
 	}
 
 	/** @internal*/ _redo(editId: number) {
-		const editing = this.getEditingCapability();
+		const editing = this.getEditingDelegate();
 		const edit = this.#_edits.get(editId, 0);
-		return editing.applyEdits([edit]);
+		return editing.applyEdits(this, [edit]);
 	}
 
 	/** @internal*/ _save(cancellation: CancellationToken) {
-		return this.getEditingCapability().save(cancellation);
+		return this.getEditingDelegate().save(this, cancellation);
 	}
 
 	/** @internal*/ _saveAs(target: vscode.Uri) {
-		return this.getEditingCapability().saveAs(target);
+		return this.getEditingDelegate().saveAs(this, target);
 	}
 
 	/** @internal*/ _backup(cancellation: CancellationToken) {
-		return this.getEditingCapability().backup(cancellation);
+		return this.getEditingDelegate().backup(this, cancellation);
 	}
 
 	/** @internal*/ _disposeEdits(editIds: number[]) {
@@ -338,13 +332,17 @@ class CustomDocument extends Disposable implements vscode.CustomDocument {
 		}
 	}
 
+	/** @internal*/ _pushEdit(edit: unknown): number {
+		return this.#_edits.add([edit]);
+	}
+
 	//#endregion
 
-	private getEditingCapability(): vscode.CustomEditorEditingCapability {
-		if (!this.#capabilities?.editing) {
+	private getEditingDelegate(): vscode.CustomEditorEditingDelegate {
+		if (!this.#editingDelegate) {
 			throw new Error('Document is not editable');
 		}
-		return this.#capabilities.editing;
+		return this.#editingDelegate;
 	}
 }
 
@@ -487,17 +485,24 @@ export class ExtHostWebviews implements ExtHostWebviewsShape {
 		provider: vscode.CustomEditorProvider | vscode.CustomTextEditorProvider,
 		options: vscode.WebviewPanelOptions | undefined = {}
 	): vscode.Disposable {
-		let disposable: vscode.Disposable;
+		const disposables = new DisposableStore();
 		if ('resolveCustomTextEditor' in provider) {
-			disposable = this._editorProviders.addTextProvider(viewType, extension, provider);
+			disposables.add(this._editorProviders.addTextProvider(viewType, extension, provider));
 			this._proxy.$registerTextEditorProvider(toExtensionData(extension), viewType, options);
 		} else {
-			disposable = this._editorProviders.addCustomProvider(viewType, extension, provider);
+			disposables.add(this._editorProviders.addCustomProvider(viewType, extension, provider));
 			this._proxy.$registerCustomEditorProvider(toExtensionData(extension), viewType, options);
+			if (provider.editingDelegate) {
+				disposables.add(provider.editingDelegate.onDidEdit(e => {
+					const document = e.document;
+					const editId = (document as CustomDocument)._pushEdit(e.edit);
+					this._proxy.$onDidEdit(document.uri, document.viewType, editId, e.label);
+				}));
+			}
 		}
 
 		return VSCodeDisposable.from(
-			disposable,
+			disposables,
 			new VSCodeDisposable(() => {
 				this._proxy.$unregisterEditorProvider(viewType);
 			}));
@@ -592,12 +597,11 @@ export class ExtHostWebviews implements ExtHostWebviewsShape {
 		}
 
 		const revivedResource = URI.revive(resource);
-		const document = CustomDocument.create(this._proxy, viewType, revivedResource);
-		const capabilities = await entry.provider.resolveCustomDocument(document);
-		document._setCapabilities(capabilities);
+		const document = CustomDocument.create(viewType, revivedResource, entry.provider.editingDelegate);
+		await entry.provider.resolveCustomDocument(document);
 		this._documents.add(document);
 		return {
-			editable: !!capabilities.editing
+			editable: !!entry.provider.editingDelegate,
 		};
 	}