Merge commit 'be3e8236086165e5e45a5a10783823874b3f3ebd' as 'lib/vscode'

lib/vscode/src/vs/base/browser/event.ts

@@ -0,0 +1,40 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { Event as BaseEvent, Emitter } from 'vs/base/common/event';
+
+export type EventHandler = HTMLElement | HTMLDocument | Window;
+
+export interface IDomEvent {
+	<K extends keyof HTMLElementEventMap>(element: EventHandler, type: K, useCapture?: boolean): BaseEvent<HTMLElementEventMap[K]>;
+	(element: EventHandler, type: string, useCapture?: boolean): BaseEvent<any>;
+}
+
+export const domEvent: IDomEvent = (element: EventHandler, type: string, useCapture?: boolean) => {
+	const fn = (e: Event) => emitter.fire(e);
+	const emitter = new Emitter<Event>({
+		onFirstListenerAdd: () => {
+			element.addEventListener(type, fn, useCapture);
+		},
+		onLastListenerRemove: () => {
+			element.removeEventListener(type, fn, useCapture);
+		}
+	});
+
+	return emitter.event;
+};
+
+export interface CancellableEvent {
+	preventDefault(): void;
+	stopPropagation(): void;
+}
+
+export function stop<T extends CancellableEvent>(event: BaseEvent<T>): BaseEvent<T> {
+	return BaseEvent.map(event, e => {
+		e.preventDefault();
+		e.stopPropagation();
+		return e;
+	});
+}