notebook: initial renderer communication

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

@@ -0,0 +1,56 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { Emitter } from 'vs/base/common/event';
+import { ExtHostNotebookRenderersShape, IMainContext, MainContext, MainThreadNotebookRenderersShape } from 'vs/workbench/api/common/extHost.protocol';
+import { ExtHostNotebookController } from 'vs/workbench/api/common/extHostNotebook';
+import * as vscode from 'vscode';
+
+export class ExtHostNotebookRenderers implements ExtHostNotebookRenderersShape {
+	private readonly _rendererMessageEmitters = new Map<string /* rendererId */, Emitter<{ document: vscode.NotebookEditor, data: any }>>();
+	private readonly proxy: MainThreadNotebookRenderersShape;
+
+	constructor(mainContext: IMainContext, private readonly _extHostNotebook: ExtHostNotebookController) {
+		this.proxy = mainContext.getProxy(MainContext.MainThreadNotebookRenderers);
+	}
+
+	public $postRendererMessage(editorId: string, rendererId: string, message: unknown): void {
+		const editor = this._extHostNotebook.getEditorById(editorId);
+		if (!editor) {
+			return;
+		}
+
+		this._rendererMessageEmitters.get(rendererId)?.fire({ document: editor.apiEditor, data: message });
+	}
+
+	public createRendererMessaging<TSend, TRecv>(rendererId: string): vscode.NotebookRendererMessaging<TSend, TRecv> {
+		const emitter = this.getOrCreateEmitterFor(rendererId);
+		const listener = emitter.event(e => messaging.messageHandler?.(e.document, e.data));
+		const messaging: vscode.NotebookRendererMessaging<TSend, TRecv> = {
+			dispose: () => listener.dispose(),
+			postMessage: message => this.proxy.$postMessage(rendererId, message),
+		};
+
+		return messaging;
+	}
+
+	private getOrCreateEmitterFor(rendererId: string) {
+		let emitter = this._rendererMessageEmitters.get(rendererId);
+		if (emitter) {
+			return emitter;
+		}
+
+		emitter = new Emitter({
+			onLastListenerRemove: () => {
+				emitter?.dispose();
+				this._rendererMessageEmitters.delete(rendererId);
+			}
+		});
+
+		this._rendererMessageEmitters.set(rendererId, emitter);
+
+		return emitter;
+	}
+}