/**
 * -------------------------------------------------------------------- jQuery-Plugin "preloadCssImages" by Scott Jehl, scott@filamentgroup.com http://www.filamentgroup.com reference article: http://www.filamentgroup.com/lab/update_automatically_preload_images_from_css_with_jquery/ demo page: http://www.filamentgroup.com/examples/preloadImages/index_v2.php
 * 
 * Copyright (c) 2008 Filament Group, Inc Dual licensed under the MIT (filamentgroup.com/examples/mit-license.txt) and GPL (filamentgroup.com/examples/gpl-license.txt) licenses.
 * 
 * Version: 3.0, 06.21.2008 Changelog: 02.20.2008 initial Version 1.0 06.04.2008 Version 2.0 : removed need for any passed arguments. Images load from any and all directories. 06.21.2008 Version 3.0 : Added options for loading status. Fixed IE abs image path bug (thanks Sam Pohlenz). --------------------------------------------------------------------
 */
jQuery.preloadCssImages = function(settings) {
	var settings = jQuery.extend( {
		statusTextEl : null,
		statusBarEl : null
	}, settings);

	var allImgs = [];// new array for all the image urls
	var k = 0; // iterator for adding images
	var sheets = document.styleSheets;// array of stylesheets

	for ( var i = 0; i < sheets.length; i++) {// loop through each stylesheet
		var cssPile = '';// create large string of all css rules in sheet
		var csshref = (sheets[i].href) ? sheets[i].href : 'window.location.href';
		var baseURLarr = csshref.split('/');// split href at / to make array
		baseURLarr.pop();// remove file path from baseURL array
		var baseURL = baseURLarr.join('/');// create base url for the images in this sheet (css file's dir)
		if (baseURL != "")
			baseURL += '/'; // tack on a / if needed
		if (document.styleSheets[i].cssRules) {// w3
			var thisSheetRules = document.styleSheets[i].cssRules; // w3
			for ( var j = 0; j < thisSheetRules.length; j++) {
				cssPile += thisSheetRules[j].cssText;
			}
		} else {
			cssPile += document.styleSheets[i].cssText;
		}

		// parse cssPile for image urls and load them into the DOM
		var imgUrls = cssPile.match(/[^\(]+\.(gif|jpg|jpeg|png)/g);// reg ex to get a string of between a "(" and a ".filename"
		var loaded = 0; // number of images loaded
		if (imgUrls != null && imgUrls.length > 0 && imgUrls != '') {// loop array\
			var arr = jQuery.makeArray(imgUrls);// create array from regex obj
			jQuery(arr).each(function() {
				allImgs[k] = new Image(); // new img obj
					allImgs[k].src = (this.charAt(0) == '/' || this.match('http://')) ? this : baseURL + this; // set src either absolute or rel to css dir

					$(allImgs[k]).load(function() {
						loaded++;
						// send updates to status elements if applicable
							if (settings.statusTextEl) {
								$(settings.statusTextEl).html('<span class="numLoaded">' + loaded + '</span> of <span class="numTotal">' + allImgs.length + '</span> loaded (<span class="percentLoaded">' + (loaded / allImgs.length * 100).toFixed(0) + '%</span>) <span class="currentImg">Cargando: <span>' + allImgs[loaded - 1].src.split('/')[allImgs[loaded - 1].src.split('/').length - 1] + '</span></span>');
							}
							if (settings.statusBarEl) {
								var barWidth = $(settings.statusBarEl).width();
								$(settings.statusBarEl).css('background-position', -(barWidth - (barWidth * loaded / allImgs.length).toFixed(0)) + 'px 50%');
							}
						});
					k++;
				});
		}
	}//loop
	return allImgs;
}