QQ space picture pop-up effect code implemented by JS_javascript skills

The example in this article describes the QQ space picture pop-up effect code implemented by JS. Share it with everyone for your reference, the details are as follows:

<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>

html part:

<a class="add" href="javascript:;" onclick="imageShow('img/hn_bg.jpg')">
<span>图片效果</span>
</a>

Readers who are interested in more JavaScript-related content can check out the special topics on this site: "Summary of JavaScript search algorithm techniques", "Summary of JavaScript animation special effects and techniques", "Summary of JavaScript errors and debugging techniques", "Summary of JavaScript data structures and algorithm techniques", "Summary of JavaScript traversal algorithms and techniques" and "JavaScript Mathematics Summary of operation usage》

I hope this article will be helpful to everyone in JavaScript programming.