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1 // Copyright (c) 2011 The Chromium Authors. All rights reserved. | 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 | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 /** | 5 /** |
6 * @fileoverview EventTracker is a simple class that manages the addition and | 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 | 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 | 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 | 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 | 10 * when the listener is a generated function such as a lambda or the result of |
11 * calling Function.bind. | 11 * calling Function.bind. |
12 */ | 12 */ |
13 | 13 |
14 /** | 14 /** |
15 * The type of the internal tracking entry. TODO(dbeam): move this back to | 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 | 16 * EventTracker.Entry when https://github.com/google/closure-compiler/issues/544 |
17 * is fixed. | 17 * is fixed. |
18 * @typedef {{node: !Node, | 18 * @typedef {{node: !Node, |
19 * eventType: string, | 19 * eventType: string, |
20 * listener: Function, | 20 * listener: Function, |
21 * capture: boolean}} | 21 * capture: boolean}} |
22 */ | 22 */ |
23 var EventTrackerEntry; | 23 var EventTrackerEntry; |
24 | 24 |
25 // Use an anonymous function to enable strict mode just for this file (which | 25 /** |
26 // will be concatenated with other files when embedded in Chrome). | 26 * Create an EventTracker to track a set of events. |
27 var EventTracker = (function() { | 27 * EventTracker instances are typically tied 1:1 with other objects or |
28 'use strict'; | 28 * DOM elements whose listeners should be removed when the object is disposed |
| 29 * or the corresponding elements are removed from the DOM. |
| 30 * @constructor |
| 31 */ |
| 32 function EventTracker() { |
| 33 /** |
| 34 * @type {Array.<EventTrackerEntry>} |
| 35 * @private |
| 36 */ |
| 37 this.listeners_ = []; |
| 38 } |
| 39 |
| 40 EventTracker.prototype = { |
| 41 /** |
| 42 * Add an event listener - replacement for Node.addEventListener. |
| 43 * @param {!Node} node The DOM node to add a listener to. |
| 44 * @param {string} eventType The type of event to subscribe to. |
| 45 * @param {Function} listener The listener to add. |
| 46 * @param {boolean} capture Whether to invoke during the capture phase. |
| 47 */ |
| 48 add: function(node, eventType, listener, capture) { |
| 49 var h = { |
| 50 node: node, |
| 51 eventType: eventType, |
| 52 listener: listener, |
| 53 capture: capture |
| 54 }; |
| 55 this.listeners_.push(h); |
| 56 node.addEventListener(eventType, listener, capture); |
| 57 }, |
29 | 58 |
30 /** | 59 /** |
31 * Create an EventTracker to track a set of events. | 60 * Remove any specified event listeners added with this EventTracker. |
32 * EventTracker instances are typically tied 1:1 with other objects or | 61 * @param {!Node} node The DOM node to remove a listener from. |
33 * DOM elements whose listeners should be removed when the object is disposed | 62 * @param {?string} eventType The type of event to remove. |
34 * or the corresponding elements are removed from the DOM. | |
35 * @constructor | |
36 */ | 63 */ |
37 function EventTracker() { | 64 remove: function(node, eventType) { |
38 /** | 65 this.listeners_ = this.listeners_.filter(function(h) { |
39 * @type {Array.<EventTrackerEntry>} | 66 if (h.node == node && (!eventType || (h.eventType == eventType))) { |
40 * @private | 67 EventTracker.removeEventListener_(h); |
41 */ | 68 return false; |
| 69 } |
| 70 return true; |
| 71 }); |
| 72 }, |
| 73 |
| 74 /** |
| 75 * Remove all event listeners added with this EventTracker. |
| 76 */ |
| 77 removeAll: function() { |
| 78 this.listeners_.forEach(EventTracker.removeEventListener_); |
42 this.listeners_ = []; | 79 this.listeners_ = []; |
43 } | 80 } |
| 81 }; |
44 | 82 |
45 EventTracker.prototype = { | 83 /** |
46 /** | 84 * Remove a single event listener given it's tracking entry. It's up to the |
47 * Add an event listener - replacement for Node.addEventListener. | 85 * caller to ensure the entry is removed from listeners_. |
48 * @param {!Node} node The DOM node to add a listener to. | 86 * @param {EventTrackerEntry} h The entry describing the listener to remove. |
49 * @param {string} eventType The type of event to subscribe to. | 87 * @private |
50 * @param {Function} listener The listener to add. | 88 */ |
51 * @param {boolean} capture Whether to invoke during the capture phase. | 89 EventTracker.removeEventListener_ = function(h) { |
52 */ | 90 h.node.removeEventListener(h.eventType, h.listener, h.capture); |
53 add: function(node, eventType, listener, capture) { | 91 }; |
54 var h = { | |
55 node: node, | |
56 eventType: eventType, | |
57 listener: listener, | |
58 capture: capture | |
59 }; | |
60 this.listeners_.push(h); | |
61 node.addEventListener(eventType, listener, capture); | |
62 }, | |
63 | |
64 /** | |
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. | |
68 */ | |
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); | |
73 return false; | |
74 } | |
75 return true; | |
76 }); | |
77 }, | |
78 | |
79 /** | |
80 * Remove all event listeners added with this EventTracker. | |
81 */ | |
82 removeAll: function() { | |
83 this.listeners_.forEach(EventTracker.removeEventListener_); | |
84 this.listeners_ = []; | |
85 } | |
86 }; | |
87 | |
88 /** | |
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. | |
92 * @private | |
93 */ | |
94 EventTracker.removeEventListener_ = function(h) { | |
95 h.node.removeEventListener(h.eventType, h.listener, h.capture); | |
96 }; | |
97 | |
98 return EventTracker; | |
99 })(); | |
100 | |
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