js 仿QQ空间图片弹出效果

<script type="text/javascript">

function imageShow(which_click) {

	var image_path = which_click;
	//alert(image_path);
	var tag_top = Math.max(document.documentElement.scrollTop, document.body.scrollTop);

	//创建底层灰色DIV
	var index_tag = document.createElement("div");
	index_tag.style.cssText = "width:100%;height:"+Math.max(document.body.clientHeight,document.body.offsetHeight,document.documentElement.clientHeight)+"px;position:relative;background:black;top:0;filter: Alpha(Opacity=80);Opacity:0.8;";
	document.body.appendChild(index_tag);
	//index_tag.ondblclick = closeIndexTag;
	index_tag.onclick = closeIndexTag;
		
	//创建图片DIV
	var img_tag = document.createElement("div");
	img_tag.style.cssText = "font:12px/18px verdana;overflow:auto;text-align:center;position:absolute;width:200px;border:5px solid white;background:white;color:white;left:"+(parseInt(document.body.offsetWidth)/2-100)+"px;top:"+(document.documentElement.clientHeight/3+tag_top)+"px;";
	img_tag.innerHTML = "<div style=‘padding:10px;background:#cccccc;border:1px solid white‘><img src=‘images/loading.gif‘ /><br /><br /><b style=‘color:#999999;font-weight:normal‘>Image loading...</b><br /></div>";
	
	img_tag.oncontextmenu = function() {
		var clsOK=confirm("是否确定关闭图片显示"); 
		if(clsOK)
			closeIndexTag();
		return false;
	}
	img_tag.onclick = closeIndexTag;
	
	//img_tag.onmousemove = barDidplay;
	document.body.appendChild(img_tag);
		
	//构建图片关闭按钮
	var close_tag = document.createElement("div");
	close_tag.style.cssText = "display:none;position:absolute;left:10px;top:10px;color:black;";
	close_tag.innerHTML = "<b style=‘background:none;border:0px solid white;filter:Alpha(Opacity=50);Opacity:0.5;cursor:pointer;‘> 关闭 </b>";
	close_tag.onclick = closeIndexTag;
	
	var img = new Image();
	img.src = image_path;
	img.style.cssText = "border:1px solid #cccccc;filter: Alpha(Opacity=0);Opacity:0;cursor:pointer";
	img.onload = imgOK();

	function imgOK() {
		var temp = 0;
		
		var stop_x = false;
		var stop_y = false;
		var img_tag_x = img_tag.offsetWidth;
		var img_tag_y = img_tag.offsetHeight;
		var img_x = img.width;
		var img_y = img.height;
		var scroll_x=document.documentElement.clientWidth;
		var scroll_y=window.innerHeight||document.documentElement.clientHeight;
		var yy = 0;
		var xx = 0;
		if(img_y > scroll_y || img_x > scroll_x){
			yy = scroll_y - 100;
			xx = (img_x / img_y) * yy;
		}else{
			xx = img_x + 4;
			yy = img_y + 3;
		}
		img.style.width=xx-4+‘px‘;
		img.style.height=yy-3+‘px‘;
		
		var maxTime = setInterval(function() {
			temp += 30;
			if((img_tag_x + temp) < xx) {
				img_tag.style.width = (img_tag_x + temp) + "px";
				img_tag.style.left = (scroll_x - img_tag_x - temp)/2 + "px";
			} else {
				stop_x = true;
				img_tag.style.width = xx + "px";
				img_tag.style.left = (scroll_x - xx)/2 + "px";
			}
			if((img_tag_y + temp) < yy) {
				img_tag.style.height = (img_tag_y + temp) + "px";
				img_tag.style.top = (tag_top + (scroll_y - img_tag_y - temp)/2) + "px";
			} else {
				stop_y = true;
				img_tag.style.height = yy + "px";
				img_tag.style.top = (tag_top + (scroll_y - yy)/2) + "px";
			}
			if(stop_x && stop_y) {
				clearInterval(maxTime);
				img_tag.appendChild(img);
				temp = 0;
				imgOpacity(temp);
			}
		}, 1);
		
		img_tag.innerHTML="";
		img_tag.appendChild(close_tag);
		
	}
	
	function closeIndexTag() {
		document.body.removeChild(index_tag);
		document.body.removeChild(img_tag);
	}

	function imgOpacity(temp_imgOpacity) {
		var temp = temp_imgOpacity;
		temp += 10;
		img.style.filter = "alpha(opacity=" + temp + ")";
		img.style.opacity = temp/100;
		var imgTime = setTimeout(function() {imgOpacity(temp);}, 10);
		if(temp > 100)
			clearTimeout(imgTime);
	}
		
	var bar_show;
	function barDidplay(){
		clearTimeout(bar_show);
		close_tag.style.display = "block";
		bar_show = setTimeout(function() {close_tag.style.display = "none"}, 1000);
	}
}
</script>