remove event emitter from focus tracker

src/vs/base/browser/dom.ts

@@ -8,13 +8,14 @@ import * as platform from 'vs/base/common/platform';
 import { TPromise } from 'vs/base/common/winjs.base';
 import { TimeoutTimer } from 'vs/base/common/async';
 import { onUnexpectedError } from 'vs/base/common/errors';
-import { EventEmitter } from 'vs/base/common/eventEmitter';
-import { Disposable, IDisposable } from 'vs/base/common/lifecycle';
+import { Disposable, IDisposable, dispose } from 'vs/base/common/lifecycle';
 import { isObject } from 'vs/base/common/types';
 import * as browser from 'vs/base/browser/browser';
 import { IKeyboardEvent, StandardKeyboardEvent } from 'vs/base/browser/keyboardEvent';
 import { IMouseEvent, StandardMouseEvent } from 'vs/base/browser/mouseEvent';
 import { CharCode } from 'vs/base/common/charCode';
+import Event, { Emitter } from 'vs/base/common/event';
+import { domEvent } from 'vs/base/browser/event';
 
 export function clearNode(node: HTMLElement) {
 	while (node.firstChild) {
@@ -417,12 +418,17 @@ export interface IEventMerger<R, E> {
 	(lastEvent: R, currentEvent: E): R;
 }
 
+export interface DOMEvent {
+	preventDefault(): void;
+	stopPropagation(): void;
+}
+
 const MINIMUM_TIME_MS = 16;
-const DEFAULT_EVENT_MERGER: IEventMerger<Event, Event> = function (lastEvent: Event, currentEvent: Event) {
+const DEFAULT_EVENT_MERGER: IEventMerger<DOMEvent, DOMEvent> = function (lastEvent: DOMEvent, currentEvent: DOMEvent) {
 	return currentEvent;
 };
 
-class TimeoutThrottledDomListener<R, E extends Event> extends Disposable {
+class TimeoutThrottledDomListener<R, E extends DOMEvent> extends Disposable {
 
 	constructor(node: any, type: string, handler: (event: R) => void, eventMerger: IEventMerger<R, E> = <any>DEFAULT_EVENT_MERGER, minimumTimeMs: number = MINIMUM_TIME_MS) {
 		super();
@@ -452,7 +458,7 @@ class TimeoutThrottledDomListener<R, E extends Event> extends Disposable {
 	}
 }
 
-export function addDisposableThrottledListener<R, E extends Event = Event>(node: any, type: string, handler: (event: R) => void, eventMerger?: IEventMerger<R, E>, minimumTimeMs?: number): IDisposable {
+export function addDisposableThrottledListener<R, E extends DOMEvent = DOMEvent>(node: any, type: string, handler: (event: R) => void, eventMerger?: IEventMerger<R, E>, minimumTimeMs?: number): IDisposable {
 	return new TimeoutThrottledDomListener<R, E>(node, type, handler, eventMerger, minimumTimeMs);
 }
 
@@ -813,8 +819,8 @@ export const EventHelper = {
 };
 
 export interface IFocusTracker {
-	addBlurListener(fn: () => void): IDisposable;
-	addFocusListener(fn: () => void): IDisposable;
+	onDidFocus: Event<void>;
+	onDidBlur: Event<void>;
 	dispose(): void;
 }
 
@@ -836,49 +842,49 @@ export function restoreParentsScrollTop(node: Element, state: number[]): void {
 	}
 }
 
-class FocusTracker extends Disposable implements IFocusTracker {
+class FocusTracker implements IFocusTracker {
 
-	private _eventEmitter: EventEmitter;
+	private _onDidFocus = new Emitter<void>();
+	readonly onDidFocus: Event<void> = this._onDidFocus.event;
 
-	constructor(element: HTMLElement | Window) {
-		super();
+	private _onDidBlur = new Emitter<void>();
+	readonly onDidBlur: Event<void> = this._onDidBlur.event;
 
+	private disposables: IDisposable[] = [];
+
+	constructor(element: HTMLElement | Window) {
 		let hasFocus = false;
 		let loosingFocus = false;
 
-		this._eventEmitter = this._register(new EventEmitter());
-
-		let onFocus = (event: Event) => {
+		let onFocus = () => {
 			loosingFocus = false;
 			if (!hasFocus) {
 				hasFocus = true;
-				this._eventEmitter.emit('focus', {});
+				this._onDidFocus.fire();
 			}
 		};
 
-		let onBlur = (event: Event) => {
+		let onBlur = () => {
 			if (hasFocus) {
 				loosingFocus = true;
 				window.setTimeout(() => {
 					if (loosingFocus) {
 						loosingFocus = false;
 						hasFocus = false;
-						this._eventEmitter.emit('blur', {});
+						this._onDidBlur.fire();
 					}
 				}, 0);
 			}
 		};
 
-		this._register(addDisposableListener(element, EventType.FOCUS, onFocus, true));
-		this._register(addDisposableListener(element, EventType.BLUR, onBlur, true));
-	}
-
-	public addFocusListener(fn: () => void): IDisposable {
-		return this._eventEmitter.addListener('focus', fn);
+		domEvent(element, EventType.FOCUS, true)(onFocus, null, this.disposables);
+		domEvent(element, EventType.BLUR, true)(onBlur, null, this.disposables);
 	}
 
-	public addBlurListener(fn: () => void): IDisposable {
-		return this._eventEmitter.addListener('blur', fn);
+	dispose(): void {
+		this.disposables = dispose(this.disposables);
+		this._onDidFocus.dispose();
+		this._onDidBlur.dispose();
 	}
 }
 
@@ -1007,7 +1013,7 @@ export function getElementsByTagName(tag: string): HTMLElement[] {
 	return Array.prototype.slice.call(document.getElementsByTagName(tag), 0);
 }
 
-export function finalHandler<T extends Event>(fn: (event: T) => any): (event: T) => any {
+export function finalHandler<T extends DOMEvent>(fn: (event: T) => any): (event: T) => any {
 	return e => {
 		e.preventDefault();
 		e.stopPropagation();

src/vs/base/browser/ui/actionbar/actionbar.ts

@@ -487,14 +487,14 @@ export class ActionBar implements IActionRunner {
 		});
 
 		this.focusTracker = DOM.trackFocus(this.domNode);
-		this.focusTracker.addBlurListener(() => {
+		this.toDispose.push(this.focusTracker.onDidBlur(() => {
 			if (document.activeElement === this.domNode || !DOM.isAncestor(document.activeElement, this.domNode)) {
 				this._onDidBlur.fire();
 				this.focusedItem = undefined;
 			}
-		});
+		}));
 
-		this.focusTracker.addFocusListener(() => this.updateFocusedItem());
+		this.toDispose.push(this.focusTracker.onDidFocus(() => this.updateFocusedItem()));
 
 		this.actionsList = document.createElement('ul');
 		this.actionsList.className = 'actions-container';

src/vs/base/browser/ui/splitview/panelview.ts

@@ -146,8 +146,8 @@ export abstract class Panel implements IView {
 		this.renderHeader(this.header);
 
 		const focusTracker = trackFocus(this.header);
-		focusTracker.addFocusListener(() => addClass(this.header, 'focused'));
-		focusTracker.addBlurListener(() => removeClass(this.header, 'focused'));
+		focusTracker.onDidFocus(() => addClass(this.header, 'focused'));
+		focusTracker.onDidBlur(() => removeClass(this.header, 'focused'));
 
 		this.updateHeader();
 

src/vs/base/parts/tree/browser/treeView.ts

@@ -485,8 +485,8 @@ export class TreeView extends HeightMap {
 		}
 
 		var focusTracker = DOM.trackFocus(this.domNode);
-		focusTracker.addFocusListener(() => this.onFocus());
-		focusTracker.addBlurListener(() => this.onBlur());
+		this.viewListeners.push(focusTracker.onDidFocus(() => this.onFocus()));
+		this.viewListeners.push(focusTracker.onDidBlur(() => this.onBlur()));
 		this.viewListeners.push(focusTracker);
 
 		this.viewListeners.push(DOM.addDisposableListener(this.domNode, 'keydown', (e) => this.onKeyDown(e)));

src/vs/editor/browser/widget/codeEditorWidget.ts

@@ -468,14 +468,14 @@ class CodeEditorWidgetFocusTracker extends Disposable {
 		this._hasFocus = false;
 		this._domFocusTracker = this._register(dom.trackFocus(domElement));
 
-		this._domFocusTracker.addFocusListener(() => {
+		this._register(this._domFocusTracker.onDidFocus(() => {
 			this._hasFocus = true;
 			this._onChange.fire(void 0);
-		});
-		this._domFocusTracker.addBlurListener(() => {
+		}));
+		this._register(this._domFocusTracker.onDidBlur(() => {
 			this._hasFocus = false;
 			this._onChange.fire(void 0);
-		});
+		}));
 	}
 
 	public hasFocus(): boolean {

src/vs/editor/contrib/find/findWidget.ts

@@ -193,7 +193,7 @@ export class FindWidget extends Widget implements IOverlayWidget, IHorizontalSas
 		}));
 		this._findInputFocused = CONTEXT_FIND_INPUT_FOCUSED.bindTo(contextKeyService);
 		this._focusTracker = this._register(dom.trackFocus(this._findInput.inputBox.inputElement));
-		this._focusTracker.addFocusListener(() => {
+		this._register(this._focusTracker.onDidFocus(() => {
 			this._findInputFocused.set(true);
 
 			if (this._toggleSelectionFind.checked) {
@@ -209,10 +209,10 @@ export class FindWidget extends Widget implements IOverlayWidget, IHorizontalSas
 					}
 				}
 			}
-		});
-		this._focusTracker.addBlurListener(() => {
+		}));
+		this._register(this._focusTracker.onDidBlur(() => {
 			this._findInputFocused.set(false);
-		});
+		}));
 
 		this._codeEditor.addOverlayWidget(this);
 		this._viewZone = new FindWidgetViewZone(0); // Put it before the first line then users can scroll beyond the first line.

src/vs/editor/contrib/find/simpleFindWidget.ts

@@ -113,12 +113,12 @@ export abstract class SimpleFindWidget extends Widget {
 		});
 
 		this._focusTracker = this._register(dom.trackFocus(this._innerDomNode));
-		this._register(this._focusTracker.addFocusListener(this.onFocusTrackerFocus.bind(this)));
-		this._register(this._focusTracker.addBlurListener(this.onFocusTrackerBlur.bind(this)));
+		this._register(this._focusTracker.onDidFocus(this.onFocusTrackerFocus.bind(this)));
+		this._register(this._focusTracker.onDidBlur(this.onFocusTrackerBlur.bind(this)));
 
 		this._findInputFocusTracker = this._register(dom.trackFocus(this._findInput.domNode));
-		this._register(this._findInputFocusTracker.addFocusListener(this.onFindInputFocusTrackerFocus.bind(this)));
-		this._register(this._findInputFocusTracker.addBlurListener(this.onFindInputFocusTrackerBlur.bind(this)));
+		this._register(this._findInputFocusTracker.onDidFocus(this.onFindInputFocusTrackerFocus.bind(this)));
+		this._register(this._findInputFocusTracker.onDidBlur(this.onFindInputFocusTrackerBlur.bind(this)));
 
 		this._register(dom.addDisposableListener(this._innerDomNode, 'click', (event) => {
 			event.stopPropagation();

src/vs/workbench/browser/parts/editor/editorGroupsControl.ts

@@ -424,7 +424,9 @@ export class EditorGroupsControl extends Themable implements IEditorGroupsContro
 
 		// Track focus on editor container
 		this.visibleEditorFocusTrackers[position] = DOM.trackFocus(editor.getContainer().getHTMLElement());
-		this.visibleEditorFocusTrackers[position].addFocusListener(() => {
+
+		// TODO@ben: when is this listener disposed?
+		this.visibleEditorFocusTrackers[position].onDidFocus(() => {
 			this.onFocusGained(editor);
 		});
 	}

src/vs/workbench/browser/parts/views/panelViewlet.ts

@@ -70,7 +70,7 @@ export abstract class ViewletPanel extends Panel {
 
 		const focusTracker = trackFocus(container);
 		this.disposables.push(focusTracker);
-		this.disposables.push(focusTracker.addFocusListener(() => this._onDidFocus.fire()));
+		this.disposables.push(focusTracker.onDidFocus(() => this._onDidFocus.fire()));
 	}
 
 	protected renderHeader(container: HTMLElement): void {

src/vs/workbench/parts/markers/browser/markersPanel.ts

@@ -227,9 +227,8 @@ export class MarkersPanel extends Panel {
 		}));
 
 		const focusTracker = this._register(dom.trackFocus(this.tree.getHTMLElement()));
-		focusTracker.addBlurListener(() => {
-			this.markerFocusContextKey.set(false);
-		});
+		this._register(focusTracker.onDidBlur(() => this.markerFocusContextKey.set(false)));
+		this._register(focusTracker);
 
 		this.toUnbind.push(this.listService.register(this.tree));
 	}

src/vs/workbench/parts/preferences/browser/keybindingsEditor.ts

@@ -132,8 +132,8 @@ export class KeybindingsEditor extends BaseEditor implements IKeybindingsEditor
 		this.createBody(keybindingsEditorElement);
 
 		const focusTracker = this._register(DOM.trackFocus(parentElement));
-		this._register(focusTracker.addFocusListener(() => this.keybindingsEditorContextKey.set(true)));
-		this._register(focusTracker.addBlurListener(() => this.keybindingsEditorContextKey.reset()));
+		this._register(focusTracker.onDidFocus(() => this.keybindingsEditorContextKey.set(true)));
+		this._register(focusTracker.onDidBlur(() => this.keybindingsEditorContextKey.reset()));
 	}
 
 	setInput(input: KeybindingsEditorInput): TPromise<void> {

src/vs/workbench/parts/preferences/browser/preferencesEditor.ts

@@ -662,7 +662,7 @@ class SideBySidePreferencesWidget extends Widget {
 		}));
 
 		const focusTracker = this._register(DOM.trackFocus(parentElement));
-		this._register(focusTracker.addFocusListener(() => this._onFocus.fire()));
+		this._register(focusTracker.onDidFocus(() => this._onFocus.fire()));
 	}
 
 	public setInput(defaultPreferencesEditorInput: DefaultPreferencesEditorInput, editablePreferencesEditorInput: EditorInput, options?: EditorOptions): TPromise<{ defaultPreferencesRenderer: IPreferencesRenderer<ISetting>, editablePreferencesRenderer: IPreferencesRenderer<ISetting> }> {

src/vs/workbench/parts/preferences/browser/preferencesWidgets.ts

@@ -179,8 +179,9 @@ export class SettingsGroupTitleWidget extends Widget implements IViewZone {
 		this.onclick(this.titleContainer, () => this.toggle());
 		this.onkeydown(this.titleContainer, (e) => this.onKeyDown(e));
 		const focusTracker = this._register(DOM.trackFocus(this.titleContainer));
-		focusTracker.addFocusListener(() => this.toggleFocus(true));
-		focusTracker.addBlurListener(() => this.toggleFocus(false));
+
+		this._register(focusTracker.onDidFocus(() => this.toggleFocus(true)));
+		this._register(focusTracker.onDidBlur(() => this.toggleFocus(false)));
 
 		this.icon = DOM.append(this.titleContainer, DOM.$('.expand-collapse-icon'));
 		this.title = DOM.append(this.titleContainer, DOM.$('.title'));
@@ -499,11 +500,11 @@ export class SearchWidget extends Widget {
 
 		this.inputBox.inputElement.setAttribute('aria-live', 'assertive');
 		const focusTracker = this._register(DOM.trackFocus(this.inputBox.inputElement));
-		this._register(focusTracker.addFocusListener(() => this._onFocus.fire()));
+		this._register(focusTracker.onDidFocus(() => this._onFocus.fire()));
 
 		if (this.options.focusKey) {
-			this._register(focusTracker.addFocusListener(() => this.options.focusKey.set(true)));
-			this._register(focusTracker.addBlurListener(() => this.options.focusKey.set(false)));
+			this._register(focusTracker.onDidFocus(() => this.options.focusKey.set(true)));
+			this._register(focusTracker.onDidBlur(() => this.options.focusKey.set(false)));
 		}
 	}
 

src/vs/workbench/parts/scm/electron-browser/scmViewlet.ts

@@ -561,7 +561,7 @@ export class RepositoryPanel extends ViewletPanel {
 
 	protected renderBody(container: HTMLElement): void {
 		const focusTracker = trackFocus(container);
-		this.disposables.push(focusTracker.addFocusListener(() => this.repository.focus()));
+		this.disposables.push(focusTracker.onDidFocus(() => this.repository.focus()));
 		this.disposables.push(focusTracker);
 
 		// Input

src/vs/workbench/parts/search/browser/searchViewlet.ts

@@ -317,13 +317,13 @@ export class SearchViewlet extends Viewlet {
 	}
 
 	private trackInputBox(inputFocusTracker: dom.IFocusTracker, contextKey?: IContextKey<boolean>): void {
-		this.toUnbind.push(inputFocusTracker.addFocusListener(() => {
+		this.toUnbind.push(inputFocusTracker.onDidFocus(() => {
 			this.inputBoxFocused.set(true);
 			if (contextKey) {
 				contextKey.set(true);
 			}
 		}));
-		this.toUnbind.push(inputFocusTracker.addBlurListener(() => {
+		this.toUnbind.push(inputFocusTracker.onDidBlur(() => {
 			this.inputBoxFocused.set(this.searchWidget.searchInputHasFocus()
 				|| this.searchWidget.replaceInputHasFocus()
 				|| this.inputPatternIncludes.inputHasFocus()

src/vs/workbench/parts/search/browser/searchWidget.ts

@@ -241,12 +241,8 @@ export class SearchWidget extends Widget {
 		}));
 
 		this.searchInputFocusTracker = this._register(dom.trackFocus(this.searchInput.inputBox.inputElement));
-		this._register(this.searchInputFocusTracker.addFocusListener(() => {
-			this.searchInputBoxFocused.set(true);
-		}));
-		this._register(this.searchInputFocusTracker.addBlurListener(() => {
-			this.searchInputBoxFocused.set(false);
-		}));
+		this._register(this.searchInputFocusTracker.onDidFocus(() => this.searchInputBoxFocused.set(true)));
+		this._register(this.searchInputFocusTracker.onDidBlur(() => this.searchInputBoxFocused.set(false)));
 	}
 
 	private renderReplaceInput(parent: HTMLElement): void {
@@ -268,12 +264,8 @@ export class SearchWidget extends Widget {
 		this.replaceActionBar.push([this.replaceAllAction], { icon: true, label: false });
 
 		this.replaceInputFocusTracker = this._register(dom.trackFocus(this.replaceInput.inputElement));
-		this._register(this.replaceInputFocusTracker.addFocusListener(() => {
-			this.replaceInputBoxFocused.set(true);
-		}));
-		this._register(this.replaceInputFocusTracker.addBlurListener(() => {
-			this.replaceInputBoxFocused.set(false);
-		}));
+		this._register(this.replaceInputFocusTracker.onDidFocus(() => this.replaceInputBoxFocused.set(true)));
+		this._register(this.replaceInputFocusTracker.onDidBlur(() => this.replaceInputBoxFocused.set(false)));
 	}
 
 	triggerReplaceAll(): TPromise<any> {