1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
6 * @fileoverview EventTracker is a simple class that manages the addition and
7 * removal of DOM event listeners. In particular, it keeps track of all
8 * listeners that have been added and makes it easy to remove some or all of
9 * them without requiring all the information again. This is particularly handy
10 * when the listener is a generated function such as a lambda or the result of
11 * calling Function.bind.
15 * The type of the internal tracking entry. TODO(dbeam): move this back to
16 * EventTracker.Entry when https://github.com/google/closure-compiler/issues/544
18 * @typedef {{node: !Node,
23 var EventTrackerEntry;
25 // Use an anonymous function to enable strict mode just for this file (which
26 // will be concatenated with other files when embedded in Chrome).
27 var EventTracker = (function() {
31 * Create an EventTracker to track a set of events.
32 * EventTracker instances are typically tied 1:1 with other objects or
33 * DOM elements whose listeners should be removed when the object is disposed
34 * or the corresponding elements are removed from the DOM.
37 function EventTracker() {
39 * @type {Array.<EventTrackerEntry>}
45 EventTracker.prototype = {
47 * Add an event listener - replacement for Node.addEventListener.
48 * @param {!Node} node The DOM node to add a listener to.
49 * @param {string} eventType The type of event to subscribe to.
50 * @param {Function} listener The listener to add.
51 * @param {boolean} capture Whether to invoke during the capture phase.
53 add: function(node, eventType, listener, capture) {
60 this.listeners_.push(h);
61 node.addEventListener(eventType, listener, capture);
65 * Remove any specified event listeners added with this EventTracker.
66 * @param {!Node} node The DOM node to remove a listener from.
67 * @param {?string} eventType The type of event to remove.
69 remove: function(node, eventType) {
70 this.listeners_ = this.listeners_.filter(function(h) {
71 if (h.node == node && (!eventType || (h.eventType == eventType))) {
72 EventTracker.removeEventListener_(h);
80 * Remove all event listeners added with this EventTracker.
82 removeAll: function() {
83 this.listeners_.forEach(EventTracker.removeEventListener_);
89 * Remove a single event listener given it's tracking entry. It's up to the
90 * caller to ensure the entry is removed from listeners_.
91 * @param {EventTrackerEntry} h The entry describing the listener to remove.
94 EventTracker.removeEventListener_ = function(h) {
95 h.node.removeEventListener(h.eventType, h.listener, h.capture);