65 lines
1.9 KiB
JavaScript
65 lines
1.9 KiB
JavaScript
|
"use strict";
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Copyright (c) 2013-present, Facebook, Inc.
|
||
|
|
*
|
||
|
|
* This source code is licensed under the MIT license found in the
|
||
|
|
* LICENSE file in the root directory of this source tree.
|
||
|
|
*
|
||
|
|
* @typechecks
|
||
|
|
*/
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Invokes the given callback after a specified number of milliseconds have
|
||
|
|
* elapsed, ignoring subsequent calls.
|
||
|
|
*
|
||
|
|
* For example, if you wanted to update a preview after the user stops typing
|
||
|
|
* you could do the following:
|
||
|
|
*
|
||
|
|
* elem.addEventListener('keyup', debounce(this.updatePreview, 250), false);
|
||
|
|
*
|
||
|
|
* The returned function has a reset method which can be called to cancel a
|
||
|
|
* pending invocation.
|
||
|
|
*
|
||
|
|
* var debouncedUpdatePreview = debounce(this.updatePreview, 250);
|
||
|
|
* elem.addEventListener('keyup', debouncedUpdatePreview, false);
|
||
|
|
*
|
||
|
|
* // later, to cancel pending calls
|
||
|
|
* debouncedUpdatePreview.reset();
|
||
|
|
*
|
||
|
|
* @param {function} func - the function to debounce
|
||
|
|
* @param {number} wait - how long to wait in milliseconds
|
||
|
|
* @param {*} context - optional context to invoke the function in
|
||
|
|
* @param {?function} setTimeoutFunc - an implementation of setTimeout
|
||
|
|
* if nothing is passed in the default setTimeout function is used
|
||
|
|
* @param {?function} clearTimeoutFunc - an implementation of clearTimeout
|
||
|
|
* if nothing is passed in the default clearTimeout function is used
|
||
|
|
*/
|
||
|
|
function debounce(func, wait, context, setTimeoutFunc, clearTimeoutFunc) {
|
||
|
|
setTimeoutFunc = setTimeoutFunc || setTimeout;
|
||
|
|
clearTimeoutFunc = clearTimeoutFunc || clearTimeout;
|
||
|
|
var timeout;
|
||
|
|
|
||
|
|
function debouncer() {
|
||
|
|
for (var _len = arguments.length, args = new Array(_len), _key = 0; _key < _len; _key++) {
|
||
|
|
args[_key] = arguments[_key];
|
||
|
|
}
|
||
|
|
|
||
|
|
debouncer.reset();
|
||
|
|
|
||
|
|
var callback = function callback() {
|
||
|
|
func.apply(context, args);
|
||
|
|
};
|
||
|
|
|
||
|
|
callback.__SMmeta = func.__SMmeta;
|
||
|
|
timeout = setTimeoutFunc(callback, wait);
|
||
|
|
}
|
||
|
|
|
||
|
|
debouncer.reset = function () {
|
||
|
|
clearTimeoutFunc(timeout);
|
||
|
|
};
|
||
|
|
|
||
|
|
return debouncer;
|
||
|
|
}
|
||
|
|
|
||
|
|
module.exports = debounce;
|