Preload Images

gistfile1.txt

// preload images	
function preloadImages() {
	var items = [], current = 0, errors = [], timer;
	

	
	var resetTimer = function() {
		stopTimer();
		startTimer();
	};

	var stopTimer = function() {
		if (timer) {
			clearTimeout(timer);	
		}
	};

	var startTimer = function() {
		// if process for some reason gets stuck, forcefully finish it all
		timer = setTimeout(function() {
			onProgress(100);
			onComplete();
		}, 10000);
	};

        var getImages = function(element) {
		$(element).find('*:not(script,link,style,meta,head,title)').each(function() {
			var url = "";
			
			if ($(this).css('background-image').indexOf('none') == -1) {
				url = $(this).css('background-image');
				if(url.indexOf('url') != -1) {
					var temp = url.match(/url\((.*?)\)/);
					url = temp[1].replace(/\"/g, '');
				}
			} else if ($(this).get(0).nodeName.toLowerCase() == 'img' && typeof($(this).attr('src')) != undefined) {
				url = $(this).attr('src');
			}
			
			if (url.length > 0 && $.inArray(url, items) < 0) {
				items.push(url);
			}
		});
	}

	//create preloaded image
	var preloading = function() {
		var queue = [];
		
		for (var url in items) {
			loadImg(url);
		}

		startTimer();
	};
	
	var loadImg = function(url) {
		var imgLoad = new Image();
		imgLoad.onload = completeLoading;
		imgLoad.onerror = completeLoading;
		imgLoad.src = url;
	};
	
	//update progress bar once image loaded
	var completeLoading = function() {
		current++;

		var per = Math.round((current / (items.length || 1)) * 100);
		
		//if all images loaded
		if(current >= items.length) {
			current = items.length;
			onProgress(100);
			onComplete();
		} else {
			onProgress(per);
		}
	};
	
	function onComplete() {
		stopTimer();
	}
	
	function onProgress(per) {
		resetTimer();
	}
}