source: imaps-frontend/node_modules/throttle-debounce/cjs/index.js

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Last change on this file was d565449, checked in by stefan toskovski <stefantoska84@…>, 4 weeks ago

Update repo after prototype presentation

  • Property mode set to 100644
File size: 5.5 KB
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[d565449]1'use strict';
2
3Object.defineProperty(exports, '__esModule', { value: true });
4
5/* eslint-disable no-undefined,no-param-reassign,no-shadow */
6
7/**
8 * Throttle execution of a function. Especially useful for rate limiting
9 * execution of handlers on events like resize and scroll.
10 *
11 * @param {number} delay - A zero-or-greater delay in milliseconds. For event callbacks, values around 100 or 250 (or even higher) are most useful.
12 * @param {boolean} [noTrailing] - Optional, defaults to false. If noTrailing is true, callback will only execute every `delay` milliseconds while the
13 * throttled-function is being called. If noTrailing is false or unspecified, callback will be executed one final time
14 * after the last throttled-function call. (After the throttled-function has not been called for `delay` milliseconds,
15 * the internal counter is reset).
16 * @param {Function} callback - A function to be executed after delay milliseconds. The `this` context and all arguments are passed through, as-is,
17 * to `callback` when the throttled-function is executed.
18 * @param {boolean} [debounceMode] - If `debounceMode` is true (at begin), schedule `clear` to execute after `delay` ms. If `debounceMode` is false (at end),
19 * schedule `callback` to execute after `delay` ms.
20 *
21 * @returns {Function} A new, throttled, function.
22 */
23function throttle (delay, noTrailing, callback, debounceMode) {
24 /*
25 * After wrapper has stopped being called, this timeout ensures that
26 * `callback` is executed at the proper times in `throttle` and `end`
27 * debounce modes.
28 */
29 var timeoutID;
30 var cancelled = false; // Keep track of the last time `callback` was executed.
31
32 var lastExec = 0; // Function to clear existing timeout
33
34 function clearExistingTimeout() {
35 if (timeoutID) {
36 clearTimeout(timeoutID);
37 }
38 } // Function to cancel next exec
39
40
41 function cancel() {
42 clearExistingTimeout();
43 cancelled = true;
44 } // `noTrailing` defaults to falsy.
45
46
47 if (typeof noTrailing !== 'boolean') {
48 debounceMode = callback;
49 callback = noTrailing;
50 noTrailing = undefined;
51 }
52 /*
53 * The `wrapper` function encapsulates all of the throttling / debouncing
54 * functionality and when executed will limit the rate at which `callback`
55 * is executed.
56 */
57
58
59 function wrapper() {
60 for (var _len = arguments.length, arguments_ = new Array(_len), _key = 0; _key < _len; _key++) {
61 arguments_[_key] = arguments[_key];
62 }
63
64 var self = this;
65 var elapsed = Date.now() - lastExec;
66
67 if (cancelled) {
68 return;
69 } // Execute `callback` and update the `lastExec` timestamp.
70
71
72 function exec() {
73 lastExec = Date.now();
74 callback.apply(self, arguments_);
75 }
76 /*
77 * If `debounceMode` is true (at begin) this is used to clear the flag
78 * to allow future `callback` executions.
79 */
80
81
82 function clear() {
83 timeoutID = undefined;
84 }
85
86 if (debounceMode && !timeoutID) {
87 /*
88 * Since `wrapper` is being called for the first time and
89 * `debounceMode` is true (at begin), execute `callback`.
90 */
91 exec();
92 }
93
94 clearExistingTimeout();
95
96 if (debounceMode === undefined && elapsed > delay) {
97 /*
98 * In throttle mode, if `delay` time has been exceeded, execute
99 * `callback`.
100 */
101 exec();
102 } else if (noTrailing !== true) {
103 /*
104 * In trailing throttle mode, since `delay` time has not been
105 * exceeded, schedule `callback` to execute `delay` ms after most
106 * recent execution.
107 *
108 * If `debounceMode` is true (at begin), schedule `clear` to execute
109 * after `delay` ms.
110 *
111 * If `debounceMode` is false (at end), schedule `callback` to
112 * execute after `delay` ms.
113 */
114 timeoutID = setTimeout(debounceMode ? clear : exec, debounceMode === undefined ? delay - elapsed : delay);
115 }
116 }
117
118 wrapper.cancel = cancel; // Return the wrapper function.
119
120 return wrapper;
121}
122
123/* eslint-disable no-undefined */
124/**
125 * Debounce execution of a function. Debouncing, unlike throttling,
126 * guarantees that a function is only executed a single time, either at the
127 * very beginning of a series of calls, or at the very end.
128 *
129 * @param {number} delay - A zero-or-greater delay in milliseconds. For event callbacks, values around 100 or 250 (or even higher) are most useful.
130 * @param {boolean} [atBegin] - Optional, defaults to false. If atBegin is false or unspecified, callback will only be executed `delay` milliseconds
131 * after the last debounced-function call. If atBegin is true, callback will be executed only at the first debounced-function call.
132 * (After the throttled-function has not been called for `delay` milliseconds, the internal counter is reset).
133 * @param {Function} callback - A function to be executed after delay milliseconds. The `this` context and all arguments are passed through, as-is,
134 * to `callback` when the debounced-function is executed.
135 *
136 * @returns {Function} A new, debounced function.
137 */
138
139function debounce (delay, atBegin, callback) {
140 return callback === undefined ? throttle(delay, atBegin, false) : throttle(delay, callback, atBegin !== false);
141}
142
143exports.debounce = debounce;
144exports.throttle = throttle;
145//# sourceMappingURL=index.js.map
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