move menubars modifier key emitter to dom.ts

refs #109062

src/vs/base/browser/dom.ts

@@ -10,12 +10,13 @@ import { IMouseEvent, StandardMouseEvent } from 'vs/base/browser/mouseEvent';
 import { TimeoutTimer } from 'vs/base/common/async';
 import { onUnexpectedError } from 'vs/base/common/errors';
 import { Emitter, Event } from 'vs/base/common/event';
-import { Disposable, IDisposable, toDisposable } from 'vs/base/common/lifecycle';
+import { Disposable, DisposableStore, IDisposable, toDisposable } from 'vs/base/common/lifecycle';
 import * as platform from 'vs/base/common/platform';
 import { URI } from 'vs/base/common/uri';
 import { FileAccess, RemoteAuthorities } from 'vs/base/common/network';
 import { BrowserFeatures } from 'vs/base/browser/canIUse';
 import { insane, InsaneOptions } from 'vs/base/common/insane/insane';
+import { KeyCode } from 'vs/base/common/keyCodes';
 
 export function clearNode(node: HTMLElement): void {
 	while (node.firstChild) {
@@ -1435,3 +1436,123 @@ export namespace WebFileSystemAccess {
 		return false;
 	}
 }
+
+type ModifierKey = 'alt' | 'ctrl' | 'shift';
+
+export interface IModifierKeyStatus {
+	altKey: boolean;
+	shiftKey: boolean;
+	ctrlKey: boolean;
+	lastKeyPressed?: ModifierKey;
+	lastKeyReleased?: ModifierKey;
+	event?: KeyboardEvent;
+}
+
+
+export class ModifierKeyEmitter extends Emitter<IModifierKeyStatus> {
+
+	private readonly _subscriptions = new DisposableStore();
+	private _keyStatus: IModifierKeyStatus;
+	private static instance: ModifierKeyEmitter;
+
+	private constructor() {
+		super();
+
+		this._keyStatus = {
+			altKey: false,
+			shiftKey: false,
+			ctrlKey: false
+		};
+
+		this._subscriptions.add(domEvent(document.body, 'keydown', true)(e => {
+			const event = new StandardKeyboardEvent(e);
+
+			if (e.altKey && !this._keyStatus.altKey) {
+				this._keyStatus.lastKeyPressed = 'alt';
+			} else if (e.ctrlKey && !this._keyStatus.ctrlKey) {
+				this._keyStatus.lastKeyPressed = 'ctrl';
+			} else if (e.shiftKey && !this._keyStatus.shiftKey) {
+				this._keyStatus.lastKeyPressed = 'shift';
+			} else if (event.keyCode !== KeyCode.Alt) {
+				this._keyStatus.lastKeyPressed = undefined;
+			} else {
+				return;
+			}
+
+			this._keyStatus.altKey = e.altKey;
+			this._keyStatus.ctrlKey = e.ctrlKey;
+			this._keyStatus.shiftKey = e.shiftKey;
+
+			if (this._keyStatus.lastKeyPressed) {
+				this._keyStatus.event = e;
+				this.fire(this._keyStatus);
+			}
+		}));
+
+		this._subscriptions.add(domEvent(document.body, 'keyup', true)(e => {
+			if (!e.altKey && this._keyStatus.altKey) {
+				this._keyStatus.lastKeyReleased = 'alt';
+			} else if (!e.ctrlKey && this._keyStatus.ctrlKey) {
+				this._keyStatus.lastKeyReleased = 'ctrl';
+			} else if (!e.shiftKey && this._keyStatus.shiftKey) {
+				this._keyStatus.lastKeyReleased = 'shift';
+			} else {
+				this._keyStatus.lastKeyReleased = undefined;
+			}
+
+			if (this._keyStatus.lastKeyPressed !== this._keyStatus.lastKeyReleased) {
+				this._keyStatus.lastKeyPressed = undefined;
+			}
+
+			this._keyStatus.altKey = e.altKey;
+			this._keyStatus.ctrlKey = e.ctrlKey;
+			this._keyStatus.shiftKey = e.shiftKey;
+
+			if (this._keyStatus.lastKeyReleased) {
+				this._keyStatus.event = e;
+				this.fire(this._keyStatus);
+			}
+		}));
+
+		this._subscriptions.add(domEvent(document.body, 'mousedown', true)(e => {
+			this._keyStatus.lastKeyPressed = undefined;
+		}));
+
+		this._subscriptions.add(domEvent(document.body, 'mouseup', true)(e => {
+			this._keyStatus.lastKeyPressed = undefined;
+		}));
+
+		this._subscriptions.add(domEvent(document.body, 'mousemove', true)(e => {
+			if (e.buttons) {
+				this._keyStatus.lastKeyPressed = undefined;
+			}
+		}));
+
+		this._subscriptions.add(domEvent(window, 'blur')(e => {
+			this._keyStatus.lastKeyPressed = undefined;
+			this._keyStatus.lastKeyReleased = undefined;
+			this._keyStatus.altKey = false;
+			this._keyStatus.shiftKey = false;
+			this._keyStatus.shiftKey = false;
+
+			this.fire(this._keyStatus);
+		}));
+	}
+
+	get keyStatus(): IModifierKeyStatus {
+		return this._keyStatus;
+	}
+
+	static getInstance() {
+		if (!ModifierKeyEmitter.instance) {
+			ModifierKeyEmitter.instance = new ModifierKeyEmitter();
+		}
+
+		return ModifierKeyEmitter.instance;
+	}
+
+	dispose() {
+		super.dispose();
+		this._subscriptions.dispose();
+	}
+}