discourse/vendor/assets/javascripts/jquery.ba-resize.js
2017-03-22 16:39:18 -04:00

247 lines
9.0 KiB
JavaScript

/*!
* jQuery resize event - v1.1 - 3/14/2010
* http://benalman.com/projects/jquery-resize-plugin/
*
* Copyright (c) 2010 "Cowboy" Ben Alman
* Dual licensed under the MIT and GPL licenses.
* http://benalman.com/about/license/
*/
// Script: jQuery resize event
//
// *Version: 1.1, Last updated: 3/14/2010*
//
// Project Home - http://benalman.com/projects/jquery-resize-plugin/
// GitHub - http://github.com/cowboy/jquery-resize/
// Source - http://github.com/cowboy/jquery-resize/raw/master/jquery.ba-resize.js
// (Minified) - http://github.com/cowboy/jquery-resize/raw/master/jquery.ba-resize.min.js (1.0kb)
//
// About: License
//
// Copyright (c) 2010 "Cowboy" Ben Alman,
// Dual licensed under the MIT and GPL licenses.
// http://benalman.com/about/license/
//
// About: Examples
//
// This working example, complete with fully commented code, illustrates a few
// ways in which this plugin can be used.
//
// resize event - http://benalman.com/code/projects/jquery-resize/examples/resize/
//
// 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 - 1.3.2, 1.4.1, 1.4.2
// Browsers Tested - Internet Explorer 6-8, Firefox 2-3.6, Safari 3-4, Chrome, Opera 9.6-10.1.
// Unit Tests - http://benalman.com/code/projects/jquery-resize/unit/
//
// About: Release History
//
// 1.1 - (3/14/2010) Fixed a minor bug that was causing the event to trigger
// immediately after bind in some circumstances. Also changed $.fn.data
// to $.data to improve performance.
// 1.0 - (2/10/2010) Initial release
(function($,window,undefined){
'$:nomunge'; // Used by YUI compressor.
// A jQuery object containing all non-window elements to which the resize
// event is bound.
var elems = $([]),
// Extend $.resize if it already exists, otherwise create it.
jq_resize = $.resize = $.extend( $.resize, {} ),
timeout_id,
// Reused strings.
str_setTimeout = 'setTimeout',
str_resize = 'resize',
str_data = str_resize + '-special-event',
str_delay = 'delay',
str_throttle = 'throttleWindow';
// Property: jQuery.resize.delay
//
// The numeric interval (in milliseconds) at which the resize event polling
// loop executes. Defaults to 250.
jq_resize[ str_delay ] = 250;
// Property: jQuery.resize.throttleWindow
//
// Throttle the native window object resize event to fire no more than once
// every <jQuery.resize.delay> milliseconds. Defaults to true.
//
// Because the window object has its own resize event, it doesn't need to be
// provided by this plugin, and its execution can be left entirely up to the
// browser. However, since certain browsers fire the resize event continuously
// while others do not, enabling this will throttle the window resize event,
// making event behavior consistent across all elements in all browsers.
//
// While setting this property to false will disable window object resize
// event throttling, please note that this property must be changed before any
// window object resize event callbacks are bound.
jq_resize[ str_throttle ] = true;
// Event: resize event
//
// Fired when an element's width or height changes. Because browsers only
// provide this event for the window element, for other elements a polling
// loop is initialized, running every <jQuery.resize.delay> milliseconds
// to see if elements' dimensions have changed. You may bind with either
// .resize( fn ) or .bind( "resize", fn ), and unbind with .unbind( "resize" ).
//
// Usage:
//
// > jQuery('selector').bind( 'resize', function(e) {
// > // element's width or height has changed!
// > ...
// > });
//
// Additional Notes:
//
// * The polling loop is not created until at least one callback is actually
// bound to the 'resize' event, and this single polling loop is shared
// across all elements.
//
// Double firing issue in jQuery 1.3.2:
//
// While this plugin works in jQuery 1.3.2, if an element's event callbacks
// are manually triggered via .trigger( 'resize' ) or .resize() those
// callbacks may double-fire, due to limitations in the jQuery 1.3.2 special
// events system. This is not an issue when using jQuery 1.4+.
//
// > // While this works in jQuery 1.4+
// > $(elem).css({ width: new_w, height: new_h }).resize();
// >
// > // In jQuery 1.3.2, you need to do this:
// > var elem = $(elem);
// > elem.css({ width: new_w, height: new_h });
// > elem.data( 'resize-special-event', { width: elem.width(), height: elem.height() } );
// > elem.resize();
$.event.special[ str_resize ] = {
// Called only when the first 'resize' event callback is bound per element.
setup: function() {
// Since window has its own native 'resize' event, return false so that
// jQuery will bind the event using DOM methods. Since only 'window'
// objects have a .setTimeout method, this should be a sufficient test.
// Unless, of course, we're throttling the 'resize' event for window.
if ( !jq_resize[ str_throttle ] && this[ str_setTimeout ] ) { return false; }
var elem = $(this);
// Add this element to the list of internal elements to monitor.
elems = elems.add( elem );
// Initialize data store on the element.
$.data( this, str_data, { w: elem.width(), h: elem.height() } );
// If this is the first element added, start the polling loop.
if ( elems.length === 1 ) {
loopy();
}
},
// Called only when the last 'resize' event callback is unbound per element.
teardown: function() {
// Since window has its own native 'resize' event, return false so that
// jQuery will unbind the event using DOM methods. Since only 'window'
// objects have a .setTimeout method, this should be a sufficient test.
// Unless, of course, we're throttling the 'resize' event for window.
if ( !jq_resize[ str_throttle ] && this[ str_setTimeout ] ) { return false; }
var elem = $(this);
// Remove this element from the list of internal elements to monitor.
elems = elems.not( elem );
// Remove any data stored on the element.
elem.removeData( str_data );
// If this is the last element removed, stop the polling loop.
if ( !elems.length ) {
clearTimeout( timeout_id );
}
},
// Called every time a 'resize' event callback is bound per element (new in
// jQuery 1.4).
add: function( handleObj ) {
// Since window has its own native 'resize' event, return false so that
// jQuery doesn't modify the event object. Unless, of course, we're
// throttling the 'resize' event for window.
if ( !jq_resize[ str_throttle ] && this[ str_setTimeout ] ) { return false; }
var old_handler;
// The new_handler function is executed every time the event is triggered.
// This is used to update the internal element data store with the width
// and height when the event is triggered manually, to avoid double-firing
// of the event callback. See the "Double firing issue in jQuery 1.3.2"
// comments above for more information.
function new_handler( e, w, h ) {
var elem = $(this),
data = $.data( this, str_data );
// If called from the polling loop, w and h will be passed in as
// arguments. If called manually, via .trigger( 'resize' ) or .resize(),
// those values will need to be computed.
data.w = w !== undefined ? w : elem.width();
data.h = h !== undefined ? h : elem.height();
old_handler.apply( this, arguments );
};
// This may seem a little complicated, but it normalizes the special event
// .add method between jQuery 1.4/1.4.1 and 1.4.2+
if ( $.isFunction( handleObj ) ) {
// 1.4, 1.4.1
old_handler = handleObj;
return new_handler;
} else {
// 1.4.2+
old_handler = handleObj.handler;
handleObj.handler = new_handler;
}
}
};
function loopy() {
// Start the polling loop, asynchronously.
timeout_id = window[ str_setTimeout ](function(){
// Iterate over all elements to which the 'resize' event is bound.
elems.each(function(){
var elem = $(this),
width = elem.width(),
height = elem.height(),
data = $.data( this, str_data );
// If element size has changed since the last time, update the element
// data store and trigger the 'resize' event.
if ( width !== data.w || height !== data.h ) {
elem.trigger( str_resize, [ data.w = width, data.h = height ] );
}
});
// Loop.
loopy();
}, jq_resize[ str_delay ] );
};
})(jQuery,this);