| // Copyright 2006 The Closure Library Authors. All Rights Reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS-IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| /** |
| * @fileoverview This event handler allows you to catch focusin and focusout |
| * events on descendants. Unlike the "focus" and "blur" events which do not |
| * propagate consistently, and therefore must be added to the element that is |
| * focused, this allows you to attach one listener to an ancester and you will |
| * be notified when the focus state changes of ony of its descendants. |
| * @author arv@google.com (Erik Arvidsson) |
| * @see ../demos/focushandler.html |
| */ |
| |
| goog.provide('goog.events.FocusHandler'); |
| goog.provide('goog.events.FocusHandler.EventType'); |
| |
| goog.require('goog.events'); |
| goog.require('goog.events.BrowserEvent'); |
| goog.require('goog.events.EventTarget'); |
| goog.require('goog.userAgent'); |
| |
| |
| |
| /** |
| * This event handler allows you to catch focus events when descendants gain or |
| * loses focus. |
| * @param {Element|Document} element The node to listen on. |
| * @constructor |
| * @extends {goog.events.EventTarget} |
| * @final |
| */ |
| goog.events.FocusHandler = function(element) { |
| goog.events.EventTarget.call(this); |
| |
| /** |
| * This is the element that we will listen to the real focus events on. |
| * @type {Element|Document} |
| * @private |
| */ |
| this.element_ = element; |
| |
| // In IE we use focusin/focusout and in other browsers we use a capturing |
| // listner for focus/blur |
| var typeIn = goog.userAgent.IE ? 'focusin' : 'focus'; |
| var typeOut = goog.userAgent.IE ? 'focusout' : 'blur'; |
| |
| /** |
| * Store the listen key so it easier to unlisten in dispose. |
| * @private |
| * @type {goog.events.Key} |
| */ |
| this.listenKeyIn_ = |
| goog.events.listen(this.element_, typeIn, this, !goog.userAgent.IE); |
| |
| /** |
| * Store the listen key so it easier to unlisten in dispose. |
| * @private |
| * @type {goog.events.Key} |
| */ |
| this.listenKeyOut_ = |
| goog.events.listen(this.element_, typeOut, this, !goog.userAgent.IE); |
| }; |
| goog.inherits(goog.events.FocusHandler, goog.events.EventTarget); |
| |
| |
| /** |
| * Enum type for the events fired by the focus handler |
| * @enum {string} |
| */ |
| goog.events.FocusHandler.EventType = { |
| FOCUSIN: 'focusin', |
| FOCUSOUT: 'focusout' |
| }; |
| |
| |
| /** |
| * This handles the underlying events and dispatches a new event. |
| * @param {goog.events.BrowserEvent} e The underlying browser event. |
| */ |
| goog.events.FocusHandler.prototype.handleEvent = function(e) { |
| var be = e.getBrowserEvent(); |
| var event = new goog.events.BrowserEvent(be); |
| event.type = e.type == 'focusin' || e.type == 'focus' ? |
| goog.events.FocusHandler.EventType.FOCUSIN : |
| goog.events.FocusHandler.EventType.FOCUSOUT; |
| this.dispatchEvent(event); |
| }; |
| |
| |
| /** @override */ |
| goog.events.FocusHandler.prototype.disposeInternal = function() { |
| goog.events.FocusHandler.superClass_.disposeInternal.call(this); |
| goog.events.unlistenByKey(this.listenKeyIn_); |
| goog.events.unlistenByKey(this.listenKeyOut_); |
| delete this.element_; |
| }; |