/* 
FUNCTION: Preloads images referenced in stylesheets
CALLED FROM:  _global/javascript.js
PARAMS: @titleFilter 

Added a filter param @titleFilter so we can decide which stylesheets to preload. 
This was necessary b/c the script was trying to parse BV CSS files from a different 
domain and was causing a security error. 
*/

preloadCssImages = function(titleFilter){

	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 title = sheets[i].title;
		if (title == titleFilter){
		
			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"
	
			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[0] == '/' || this.match('http://')) ? this : baseURL + this;     //set src either absolute or rel to css dir
					k++;
				});
			}
		}	
	}

	
	return allImgs;
}