IE 6透明PNG修复-SuperSlight

Posted 2021-02-27

Getting SuperSleight running on a page is quite straightforward, you just need to link the supplied javascript file into your document inside conditional comments so that it is delivered to only Internet Explorer 6 or older.

var supersleight	= function() {
 
	var root = false;
	var applyPositioning = true;
 
	// Path to a transparent GIF image
	var shim			= 'x.gif';
 
	// RegExp to match above GIF image name
	var shim_pattern	= /x.gif$/i;
 
 
 
	var fnLoadPngs = function() { 
		if (root) {
			root = document.getElementById(root);
		}else{
			root = document;
		}
		for (var i = root.all.length - 1, obj = null; (obj = root.all[i]); i--) {
			// background pngs
			if (obj.currentStyle.backgroundImage.match(/.png/i) !== null) {
				bg_fnFixPng(obj);
			}
			// image elements
			if (obj.tagName=='IMG' && obj.src.match(/.png$/i) !== null){
				el_fnFixPng(obj);
			}
			// apply position to 'active' elements
			if (applyPositioning && (obj.tagName=='A' || obj.tagName=='INPUT') && obj.style.position === ''){
				obj.style.position = 'relative';
			}
		}
	};
 
	var bg_fnFixPng = function(obj) {
		var mode = 'scale';
		var bg	= obj.currentStyle.backgroundImage;
		var src = bg.substring(5,bg.length-2);
		if (obj.currentStyle.backgroundRepeat == 'no-repeat') {
			mode = 'crop';
		}
		obj.style.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader(src='" + src + "', sizingMethod='" + mode + "')";
		obj.style.backgroundImage = 'url('+shim+')';
	};
 
	var el_fnFixPng = function(img) {
		var src = img.src;
		img.style.width = img.width + "px";
		img.style.height = img.height + "px";
		img.style.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader(src='" + src + "', sizingMethod='scale')";
		img.src = shim;
	};
 
	var addLoadEvent = function(func) {
		var oldonload = window.onload;
		if (typeof window.onload != 'function') {
			window.onload = func;
		} else {
			window.onload = function() {
				if (oldonload) {
					oldonload();
				}
				func();
			};
		}
	};
 
	return {
		init: function() { 
			addLoadEvent(fnLoadPngs);
		},
 
		limitTo: function(el) {
			root = el;
		},
 
		run: function() {
			fnLoadPngs();
		}
	};
}();
 
// limit to part of the page ... pass an ID to limitTo:
// supersleight.limitTo('header');
 
supersleight.init();