mirror of
https://github.com/codeninjasuk/codeninjasuk.github.io.git
synced 2024-11-22 23:38:01 -05:00
252 lines
10 KiB
JavaScript
252 lines
10 KiB
JavaScript
/*!
|
|
* jQuery throttle / debounce - v1.1 - 3/7/2010
|
|
* http://benalman.com/projects/jquery-throttle-debounce-plugin/
|
|
*
|
|
* Copyright (c) 2010 "Cowboy" Ben Alman
|
|
* Dual licensed under the MIT and GPL licenses.
|
|
* http://benalman.com/about/license/
|
|
*/
|
|
|
|
// Script: jQuery throttle / debounce: Sometimes, less is more!
|
|
//
|
|
// *Version: 1.1, Last updated: 3/7/2010*
|
|
//
|
|
// Project Home - http://benalman.com/projects/jquery-throttle-debounce-plugin/
|
|
// GitHub - http://github.com/cowboy/jquery-throttle-debounce/
|
|
// Source - http://github.com/cowboy/jquery-throttle-debounce/raw/master/jquery.ba-throttle-debounce.js
|
|
// (Minified) - http://github.com/cowboy/jquery-throttle-debounce/raw/master/jquery.ba-throttle-debounce.min.js (0.7kb)
|
|
//
|
|
// About: License
|
|
//
|
|
// Copyright (c) 2010 "Cowboy" Ben Alman,
|
|
// Dual licensed under the MIT and GPL licenses.
|
|
// http://benalman.com/about/license/
|
|
//
|
|
// About: Examples
|
|
//
|
|
// These working examples, complete with fully commented code, illustrate a few
|
|
// ways in which this plugin can be used.
|
|
//
|
|
// Throttle - http://benalman.com/code/projects/jquery-throttle-debounce/examples/throttle/
|
|
// Debounce - http://benalman.com/code/projects/jquery-throttle-debounce/examples/debounce/
|
|
//
|
|
// About: Support and Testing
|
|
//
|
|
// Information about what version or versions of jQuery this plugin has been
|
|
// tested with, what browsers it has been tested in, and where the unit tests
|
|
// reside (so you can test it yourself).
|
|
//
|
|
// jQuery Versions - none, 1.3.2, 1.4.2
|
|
// Browsers Tested - Internet Explorer 6-8, Firefox 2-3.6, Safari 3-4, Chrome 4-5, Opera 9.6-10.1.
|
|
// Unit Tests - http://benalman.com/code/projects/jquery-throttle-debounce/unit/
|
|
//
|
|
// About: Release History
|
|
//
|
|
// 1.1 - (3/7/2010) Fixed a bug in <jQuery.throttle> where trailing callbacks
|
|
// executed later than they should. Reworked a fair amount of internal
|
|
// logic as well.
|
|
// 1.0 - (3/6/2010) Initial release as a stand-alone project. Migrated over
|
|
// from jquery-misc repo v0.4 to jquery-throttle repo v1.0, added the
|
|
// no_trailing throttle parameter and debounce functionality.
|
|
//
|
|
// Topic: Note for non-jQuery users
|
|
//
|
|
// jQuery isn't actually required for this plugin, because nothing internal
|
|
// uses any jQuery methods or properties. jQuery is just used as a namespace
|
|
// under which these methods can exist.
|
|
//
|
|
// Since jQuery isn't actually required for this plugin, if jQuery doesn't exist
|
|
// when this plugin is loaded, the method described below will be created in
|
|
// the `Cowboy` namespace. Usage will be exactly the same, but instead of
|
|
// $.method() or jQuery.method(), you'll need to use Cowboy.method().
|
|
|
|
(function(window,undefined){
|
|
'$:nomunge'; // Used by YUI compressor.
|
|
|
|
// Since jQuery really isn't required for this plugin, use `jQuery` as the
|
|
// namespace only if it already exists, otherwise use the `Cowboy` namespace,
|
|
// creating it if necessary.
|
|
var $ = window.jQuery || window.Cowboy || ( window.Cowboy = {} ),
|
|
|
|
// Internal method reference.
|
|
jq_throttle;
|
|
|
|
// Method: jQuery.throttle
|
|
//
|
|
// Throttle execution of a function. Especially useful for rate limiting
|
|
// execution of handlers on events like resize and scroll. If you want to
|
|
// rate-limit execution of a function to a single time, see the
|
|
// <jQuery.debounce> method.
|
|
//
|
|
// In this visualization, | is a throttled-function call and X is the actual
|
|
// callback execution:
|
|
//
|
|
// > Throttled with `no_trailing` specified as false or unspecified:
|
|
// > ||||||||||||||||||||||||| (pause) |||||||||||||||||||||||||
|
|
// > X X X X X X X X X X X X
|
|
// >
|
|
// > Throttled with `no_trailing` specified as true:
|
|
// > ||||||||||||||||||||||||| (pause) |||||||||||||||||||||||||
|
|
// > X X X X X X X X X X
|
|
//
|
|
// Usage:
|
|
//
|
|
// > var throttled = jQuery.throttle( delay, [ no_trailing, ] callback );
|
|
// >
|
|
// > jQuery('selector').bind( 'someevent', throttled );
|
|
// > jQuery('selector').unbind( 'someevent', throttled );
|
|
//
|
|
// This also works in jQuery 1.4+:
|
|
//
|
|
// > jQuery('selector').bind( 'someevent', jQuery.throttle( delay, [ no_trailing, ] callback ) );
|
|
// > jQuery('selector').unbind( 'someevent', callback );
|
|
//
|
|
// Arguments:
|
|
//
|
|
// delay - (Number) A zero-or-greater delay in milliseconds. For event
|
|
// callbacks, values around 100 or 250 (or even higher) are most useful.
|
|
// no_trailing - (Boolean) Optional, defaults to false. If no_trailing is
|
|
// true, callback will only execute every `delay` milliseconds while the
|
|
// throttled-function is being called. If no_trailing is false or
|
|
// unspecified, callback will be executed one final time after the last
|
|
// throttled-function call. (After the throttled-function has not been
|
|
// called for `delay` milliseconds, the internal counter is reset)
|
|
// callback - (Function) A function to be executed after delay milliseconds.
|
|
// The `this` context and all arguments are passed through, as-is, to
|
|
// `callback` when the throttled-function is executed.
|
|
//
|
|
// Returns:
|
|
//
|
|
// (Function) A new, throttled, function.
|
|
|
|
$.throttle = jq_throttle = function( delay, no_trailing, callback, debounce_mode ) {
|
|
// After wrapper has stopped being called, this timeout ensures that
|
|
// `callback` is executed at the proper times in `throttle` and `end`
|
|
// debounce modes.
|
|
var timeout_id,
|
|
|
|
// Keep track of the last time `callback` was executed.
|
|
last_exec = 0;
|
|
|
|
// `no_trailing` defaults to falsy.
|
|
if ( typeof no_trailing !== 'boolean' ) {
|
|
debounce_mode = callback;
|
|
callback = no_trailing;
|
|
no_trailing = undefined;
|
|
}
|
|
|
|
// The `wrapper` function encapsulates all of the throttling / debouncing
|
|
// functionality and when executed will limit the rate at which `callback`
|
|
// is executed.
|
|
function wrapper() {
|
|
var that = this,
|
|
elapsed = +new Date() - last_exec,
|
|
args = arguments;
|
|
|
|
// Execute `callback` and update the `last_exec` timestamp.
|
|
function exec() {
|
|
last_exec = +new Date();
|
|
callback.apply( that, args );
|
|
};
|
|
|
|
// If `debounce_mode` is true (at_begin) this is used to clear the flag
|
|
// to allow future `callback` executions.
|
|
function clear() {
|
|
timeout_id = undefined;
|
|
};
|
|
|
|
if ( debounce_mode && !timeout_id ) {
|
|
// Since `wrapper` is being called for the first time and
|
|
// `debounce_mode` is true (at_begin), execute `callback`.
|
|
exec();
|
|
}
|
|
|
|
// Clear any existing timeout.
|
|
timeout_id && clearTimeout( timeout_id );
|
|
|
|
if ( debounce_mode === undefined && elapsed > delay ) {
|
|
// In throttle mode, if `delay` time has been exceeded, execute
|
|
// `callback`.
|
|
exec();
|
|
|
|
} else if ( no_trailing !== true ) {
|
|
// In trailing throttle mode, since `delay` time has not been
|
|
// exceeded, schedule `callback` to execute `delay` ms after most
|
|
// recent execution.
|
|
//
|
|
// If `debounce_mode` is true (at_begin), schedule `clear` to execute
|
|
// after `delay` ms.
|
|
//
|
|
// If `debounce_mode` is false (at end), schedule `callback` to
|
|
// execute after `delay` ms.
|
|
timeout_id = setTimeout( debounce_mode ? clear : exec, debounce_mode === undefined ? delay - elapsed : delay );
|
|
}
|
|
};
|
|
|
|
// Set the guid of `wrapper` function to the same of original callback, so
|
|
// it can be removed in jQuery 1.4+ .unbind or .die by using the original
|
|
// callback as a reference.
|
|
if ( $.guid ) {
|
|
wrapper.guid = callback.guid = callback.guid || $.guid++;
|
|
}
|
|
|
|
// Return the wrapper function.
|
|
return wrapper;
|
|
};
|
|
|
|
// Method: jQuery.debounce
|
|
//
|
|
// Debounce execution of a function. Debouncing, unlike throttling,
|
|
// guarantees that a function is only executed a single time, either at the
|
|
// very beginning of a series of calls, or at the very end. If you want to
|
|
// simply rate-limit execution of a function, see the <jQuery.throttle>
|
|
// method.
|
|
//
|
|
// In this visualization, | is a debounced-function call and X is the actual
|
|
// callback execution:
|
|
//
|
|
// > Debounced with `at_begin` specified as false or unspecified:
|
|
// > ||||||||||||||||||||||||| (pause) |||||||||||||||||||||||||
|
|
// > X X
|
|
// >
|
|
// > Debounced with `at_begin` specified as true:
|
|
// > ||||||||||||||||||||||||| (pause) |||||||||||||||||||||||||
|
|
// > X X
|
|
//
|
|
// Usage:
|
|
//
|
|
// > var debounced = jQuery.debounce( delay, [ at_begin, ] callback );
|
|
// >
|
|
// > jQuery('selector').bind( 'someevent', debounced );
|
|
// > jQuery('selector').unbind( 'someevent', debounced );
|
|
//
|
|
// This also works in jQuery 1.4+:
|
|
//
|
|
// > jQuery('selector').bind( 'someevent', jQuery.debounce( delay, [ at_begin, ] callback ) );
|
|
// > jQuery('selector').unbind( 'someevent', callback );
|
|
//
|
|
// Arguments:
|
|
//
|
|
// delay - (Number) A zero-or-greater delay in milliseconds. For event
|
|
// callbacks, values around 100 or 250 (or even higher) are most useful.
|
|
// at_begin - (Boolean) Optional, defaults to false. If at_begin is false or
|
|
// unspecified, callback will only be executed `delay` milliseconds after
|
|
// the last debounced-function call. If at_begin is true, callback will be
|
|
// executed only at the first debounced-function call. (After the
|
|
// throttled-function has not been called for `delay` milliseconds, the
|
|
// internal counter is reset)
|
|
// callback - (Function) A function to be executed after delay milliseconds.
|
|
// The `this` context and all arguments are passed through, as-is, to
|
|
// `callback` when the debounced-function is executed.
|
|
//
|
|
// Returns:
|
|
//
|
|
// (Function) A new, debounced, function.
|
|
|
|
$.debounce = function( delay, at_begin, callback ) {
|
|
return callback === undefined
|
|
? jq_throttle( delay, at_begin, false )
|
|
: jq_throttle( delay, callback, at_begin !== false );
|
|
};
|
|
|
|
})(this);
|