tao-test/app/taoQtiItem/views/js/portableLib/OAT/waitForMedia.js

89 lines
3.0 KiB
JavaScript

/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; under version 2
* of the License (non-upgradable).
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* Copyright (c) 2015 (original work) Open Assessment Technlogies SA ;
*
* @author Sam Sipasseuth <sam@taotesting.com>
* @requires IMSGlobal/jquery_2_1_1
*/
define(['taoQtiItem/portableLib/jquery_2_1_1'], function($){
'use strict';
var _ns = '.wait';
/**
* Register a plugin that enable waiting for all media being loaded
*
* @fires loaded.wait - fired when a media has been loaded
* @fires all-loaded.wait - fired when all media has been loaded
* @param {Function} [allLoadedCallback] - callback to be executed when all media has been loaded
* @returns {jQueryElement} for chaining
*/
$.fn.waitForMedia = function(allLoadedCallback){
/**
* The callback function that is called after loading all the documents.
*
* @param {jQueryElement} $container The container element on which will be triggered an event.
* @returns {undefined}
*/
function allLoaded($container) {
$container.trigger('all-loaded' + _ns);
if(typeof allLoadedCallback === 'function'){
allLoadedCallback.call($container[0]);
}
}
return this.each(function(){
var $container = $(this),
$img = $container.find('img'),
count = $img.length,
loaded = 0,
/**
* The function to be executed whenever an image is considered loaded
*/
imageLoaded = function () {
$(this)
.trigger('loaded' + _ns)
.off('load' + _ns)
.off('error' + _ns);
loaded++;
if(loaded === count){
allLoaded($container);
}
};
if (count === 0) {
allLoaded($container);
return;
}
$img.each(function(){
if(this.complete){
//the image is already loaded by the browser
imageLoaded.call(this);
}else{
//the image is not yet loaded : add "load" listener
$(this).on('load' + _ns + ' error' + _ns, imageLoaded);
}
});
});
};
});