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
100
101
102
103
104
105
|
/*
* Copyright (C) 2023-2024 Yomitan Authors
* Copyright (C) 2019-2022 Yomichan Authors
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
/**
* The following typedef is required because the JSDoc `implements` tag doesn't work with `import()`.
* https://github.com/microsoft/TypeScript/issues/49905
* @typedef {import('core').EventDispatcherOffGeneric} EventDispatcherOffGeneric
*/
/**
* Base class controls basic event dispatching.
* @template {import('core').EventSurface} TSurface
* @implements {EventDispatcherOffGeneric}
*/
export class EventDispatcher {
/**
* Creates a new instance.
*/
constructor() {
/** @type {Map<import('core').EventNames<TSurface>, import('core').EventHandlerAny[]>} */
this._eventMap = new Map();
}
/**
* Triggers an event with the given name and specified argument.
* @template {import('core').EventNames<TSurface>} TName
* @param {TName} eventName The string representing the event's name.
* @param {import('core').EventArgument<TSurface, TName>} details The argument passed to the callback functions.
* @returns {boolean} `true` if any callbacks were registered, `false` otherwise.
*/
trigger(eventName, details) {
const callbacks = this._eventMap.get(eventName);
if (typeof callbacks === 'undefined') { return false; }
for (const callback of callbacks) {
callback(details);
}
return true;
}
/**
* Adds a single event listener to a specific event.
* @template {import('core').EventNames<TSurface>} TName
* @param {TName} eventName The string representing the event's name.
* @param {import('core').EventHandler<TSurface, TName>} callback The event listener callback to add.
*/
on(eventName, callback) {
let callbacks = this._eventMap.get(eventName);
if (typeof callbacks === 'undefined') {
callbacks = [];
this._eventMap.set(eventName, callbacks);
}
callbacks.push(callback);
}
/**
* Removes a single event listener from a specific event.
* @template {import('core').EventNames<TSurface>} TName
* @param {TName} eventName The string representing the event's name.
* @param {import('core').EventHandler<TSurface, TName>} callback The event listener callback to add.
* @returns {boolean} `true` if the callback was removed, `false` otherwise.
*/
off(eventName, callback) {
const callbacks = this._eventMap.get(eventName);
if (typeof callbacks === 'undefined') { return false; }
const ii = callbacks.length;
for (let i = 0; i < ii; ++i) {
if (callbacks[i] === callback) {
callbacks.splice(i, 1);
if (callbacks.length === 0) {
this._eventMap.delete(eventName);
}
return true;
}
}
return false;
}
/**
* Checks if an event has any listeners.
* @template {import('core').EventNames<TSurface>} TName
* @param {TName} eventName The string representing the event's name.
* @returns {boolean} `true` if the event has listeners, `false` otherwise.
*/
hasListeners(eventName) {
const callbacks = this._eventMap.get(eventName);
return (typeof callbacks !== 'undefined' && callbacks.length > 0);
}
}
|