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
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
|
/**
* @file fn.js
* @module fn
*/
import { newGUID } from './guid.js';
import window from 'global/window';
export const UPDATE_REFRESH_INTERVAL = 30;
/**
* A private, internal-only function for changing the context of a function.
*
* It also stores a unique id on the function so it can be easily removed from
* events.
*
* @private
* @function
* @param {*} context
* The object to bind as scope.
*
* @param {Function} fn
* The function to be bound to a scope.
*
* @param {number} [uid]
* An optional unique ID for the function to be set
*
* @return {Function}
* The new function that will be bound into the context given
*/
export const bind_ = function(context, fn, uid) {
// Make sure the function has a unique ID
if (!fn.guid) {
fn.guid = newGUID();
}
// Create the new function that changes the context
const bound = fn.bind(context);
// Allow for the ability to individualize this function
// Needed in the case where multiple objects might share the same prototype
// IF both items add an event listener with the same function, then you try to remove just one
// it will remove both because they both have the same guid.
// when using this, you need to use the bind method when you remove the listener as well.
// currently used in text tracks
bound.guid = (uid) ? uid + '_' + fn.guid : fn.guid;
return bound;
};
/**
* Wraps the given function, `fn`, with a new function that only invokes `fn`
* at most once per every `wait` milliseconds.
*
* @function
* @param {Function} fn
* The function to be throttled.
*
* @param {number} wait
* The number of milliseconds by which to throttle.
*
* @return {Function}
*/
export const throttle = function(fn, wait) {
let last = window.performance.now();
const throttled = function(...args) {
const now = window.performance.now();
if (now - last >= wait) {
fn(...args);
last = now;
}
};
return throttled;
};
/**
* Creates a debounced function that delays invoking `func` until after `wait`
* milliseconds have elapsed since the last time the debounced function was
* invoked.
*
* Inspired by lodash and underscore implementations.
*
* @function
* @param {Function} func
* The function to wrap with debounce behavior.
*
* @param {number} wait
* The number of milliseconds to wait after the last invocation.
*
* @param {boolean} [immediate]
* Whether or not to invoke the function immediately upon creation.
*
* @param {Object} [context=window]
* The "context" in which the debounced function should debounce. For
* example, if this function should be tied to a Video.js player,
* the player can be passed here. Alternatively, defaults to the
* global `window` object.
*
* @return {Function}
* A debounced function.
*/
export const debounce = function(func, wait, immediate, context = window) {
let timeout;
const cancel = () => {
context.clearTimeout(timeout);
timeout = null;
};
/* eslint-disable consistent-this */
const debounced = function() {
const self = this;
const args = arguments;
let later = function() {
timeout = null;
later = null;
if (!immediate) {
func.apply(self, args);
}
};
if (!timeout && immediate) {
func.apply(self, args);
}
context.clearTimeout(timeout);
timeout = context.setTimeout(later, wait);
};
/* eslint-enable consistent-this */
debounced.cancel = cancel;
return debounced;
};
|
