1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
|
// Copyright 2019 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
window['chrome'] = window['chrome'] || {};
/**
* Sends messages to the browser. See
* https://chromium.googlesource.com/chromium/src/+/main/docs/webui_explainer.md#chrome_send
*
* @param {string} message name to be passed to the browser.
* @param {Array=} args optional.
*/
window['chrome']['send'] = function(message, args) {
__gCrWeb.message.invokeOnHost({
'command': 'webui.chromeSend',
'message': message,
'arguments': args || [],
});
};
try {
new EventTarget().constructor;
} catch {
/**
* Minimal EventTarget polyfill for webui.
* TODO(crbug.com/1173902): delete once iOS 13 is deprecated.
* @constructor
*/
const EventTarget = function() {
/**
* @type {Object}
*/
this.listeners_ = {};
};
/**
* Registers an event handler of a specific event type on the EventTarget.
* @param {string} type event type.
* @param {function} listener event callback.
* @param {object|boolean|null} options event options.
*/
EventTarget.prototype.addEventListener = function(type, listener, options) {
if (!(type in this.listeners_)) {
this.listeners_[type] = [];
}
this.listeners_[type].push({listener: listener, options: options});
};
/**
* Removes an event listener from the EventTarget.
* @param {string} type event type.
* @param {function} listener event callback.
* @param {object|boolean|null} options event options.
*/
EventTarget.prototype.removeEventListener = function(
type, listener, options) {
if (!(type in this.listeners_)) {
return;
}
const stubs = this.listeners_[type];
let i = 0;
while (i < stubs.length) {
if (stubs[i].listener === listener &&
JSON.stringify(stubs[i].options) === JSON.stringify(options)) {
stubs.splice(i, 1);
} else {
i++;
}
}
};
/**
* Dispatches an event to this EventTarget.
* @param {!Event} event event to dispatch.
* @return {boolean}
*/
EventTarget.prototype.dispatchEvent = function(event) {
if (!(event.type in this.listeners)) {
return true;
}
// Iterate on copy, in case options.once requires removing listener.
const stubs = this.listeners_[type].slice(0);
for (let i = 0; i < stubs.length; i++) {
stubs[i].listener.call(this, event);
if (typeof stubs[i].options === 'object' && stubs[i].options.once) {
this.removeEventListener(
event.type, stubs[i].listener, stubs[i].options);
}
}
return !event.defaultPrevented;
};
window.EventTarget = EventTarget;
}
|
