JavaScript method to implement DIV layer dragging and dynamically add new layers

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JavaScript method to implement DIV layer dragging and dynamically add new layers_javascript skills

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May 16, 2016 pm 03:59 PM

javascriptdrag

The example in this article describes how to implement DIV layer dragging and dynamically adding new layers using JavaScript. Share it with everyone for your reference. The specific analysis is as follows:

Add a new DIV layer without refreshing, and drag the layer. Drag the layer with the mouse to move the position. Save the JS part as a new file. When used, import it from the outside. This drag Layer code is very popular, and this effect can often be seen on large websites such as GG and YAHOO.

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>DIV层拖动，动态增加新层的JavaScript</title>
<style>
body {margin:0px;padding:0px;font-size:12px;text-align:center;}
body > div {text-align:center; margin-right:auto; margin-left:auto;} 
.content{width:900px;}
.content .left{
  float:left;
  width:20%;
  border:1px solid #0066CC;
  margin:3px;
}
.content .center{
 float:left;
 border:1px solid #FF0000;
 margin:3px;
 width:57%
}
.content .right{
 float:right;
 width:20%;
 border:1px solid #FF0000;
 margin:3px
}
.mo{
 height:auto;
 border:1px solid #CCC;
 margin:3px;
 background:#FFF
}
.mo h1{
 background:#ECF9FF;
 height:18px;
 padding:3px;
 cursor:move
}
.closediv{
 cursor:default;
}
.minusspan{
 cursor:default;
}
.mo .nr{
 height:80px;
 border:1px solid #F3F3F3;
 margin:2px
}
h1{
 margin:0px;
 padding:0px;
 text-align:left;
 font-size:12px
}
.dragging {
  FILTER: progid:DXImageTransform.Microsoft.Alpha(opacity=60);
 opacity: 0.6;
 moz-opacity: 0.6
}
</style>
<script language="javascript">
var dragobj={}
window.onerror=function(){return false}
var domid=12
function on_ini(){
  String.prototype.inc=function(s){return this.indexOf(s)>-1&#63;true:false}
  var agent=navigator.userAgent
  window.isOpr=agent.inc("Opera")
  window.isIE=agent.inc("IE") && !isOpr
  window.isMoz=agent.inc("Mozilla") && !isOpr && !isIE
  if(isMoz){
    Event.prototype.__defineGetter__("x",function(){return this.clientX+2})
    Event.prototype.__defineGetter__("y",function(){return this.clientY+2})
  }
  basic_ini()
}
function basic_ini(){
  window.$=function(obj){return typeof(obj)=="string"&#63;document.getElementById(obj):obj}
  window.oDel=function(obj){if($(obj)!=null){$(obj).parentNode.removeChild($(obj))}}
}
window.oDel=function(obj){if($(obj)!=null){$(obj).parentNode.removeChild($(obj))}}
window.onload=function(){
  on_ini()
  var o=document.getElementsByTagName("h1")
  for(var i=0;i<o.length;i++){
    o[i].onmousedown=addevent;
    //添加折叠和关闭按钮
    var tt = document.createElement("div");
    tt.style.cssText = "float:left";
    
    var span = document.createElement("span");
    span.innerHTML = "--"+o[i].innerHTML;
    span.style.cssText = "cursor:default;";
    span.onmousedown = minusDiv;
    tt.appendChild(span);
    
    var close = document.createElement("div");
    close.innerHTML = "X";
    close.style.cssText = "cursor:default;float:right";
    close.onmousedown = closeDiv;
    o[i].innerHTML = "";
    o[i].appendChild(tt);
    o[i].appendChild(close);
  }
}
//折叠或者显示层
function minusDiv(e)
{
  e=e||event
  var nr = this.parentNode.parentNode.nextSibling; //取得内容层
  nr.style.display = nr.style.display==""&#63;"none":"";
}
//移出层
function closeDiv(e)
{
  e=e||event
  var mdiv = this.parentNode.parentNode; //取得目标层
  oDel(mdiv);
}
function addevent(e){
  if(dragobj.o!=null)
    return false
  e=e||event
  dragobj.o=this.parentNode
  dragobj.xy=getxy(dragobj.o)
  dragobj.xx=new Array((e.x-dragobj.xy[1]),(e.y-dragobj.xy[0]))
  //dragobj.o.className = 'dragging';
  dragobj.o.style.width=dragobj.xy[2]+"px"
  dragobj.o.style.height=dragobj.xy[3]+"px"
  dragobj.o.style.left=(e.x-dragobj.xx[0])+"px"
  dragobj.o.style.top=(e.y-dragobj.xx[1])+"px"
  dragobj.o.style.position="absolute"
  dragobj.o.style.filter='alpha(opacity=60)'; //添加拖动透明效果
  var om=document.createElement("div")
  dragobj.otemp=om
  om.style.width=dragobj.xy[2]+"px"
  om.style.height=dragobj.xy[3]+"px"
  om.style.border = "1px dashed red"; //ikaiser添加，实现虚线框
  dragobj.o.parentNode.insertBefore(om,dragobj.o)
  return false
}
document.onselectstart=function(){return false}
window.onfocus=function(){document.onmouseup()}
window.onblur=function(){document.onmouseup()}
document.onmouseup=function(){
  if(dragobj.o!=null){
    dragobj.o.style.width="auto"
    dragobj.o.style.height="auto"
    dragobj.otemp.parentNode.insertBefore(dragobj.o,dragobj.otemp)
    dragobj.o.style.position=""
    oDel(dragobj.otemp)
    dragobj={}
  }
}
document.onmousemove=function(e){
  e=e||event
  if(dragobj.o!=null){
    dragobj.o.style.left=(e.x-dragobj.xx[0])+"px"
    dragobj.o.style.top=(e.y-dragobj.xx[1])+"px"
    createtmpl(e, dragobj.o) //传递当前拖动对象
  }
}
function getxy(e){
  var a=new Array()
  var t=e.offsetTop;
  var l=e.offsetLeft;
  var w=e.offsetWidth;
  var h=e.offsetHeight;
  while(e=e.offsetParent){
    t+=e.offsetTop;
    l+=e.offsetLeft;
  }
  a[0]=t;a[1]=l;a[2]=w;a[3]=h
 return a;
}
function inner(o,e){
  var a=getxy(o)
  if(e.x>a[1] && e.x<(a[1]+a[2]) && e.y>a[0] && e.y<(a[0]+a[3])){
    if(e.y<(a[0]+a[3]/2))
      return 1;
    else
      return 2;
  }else
    return 0;
}
//将当前拖动层在拖动时可变化大小，预览效果
function createtmpl(e, elm){
  for(var i=0;i<domid;i++){
    if(document.getElementById("m"+i) == null) //已经移出的层不再遍历
      continue;
    if($("m"+i)==dragobj.o)
      continue
    var b=inner($("m"+i),e)
    if(b==0)
      continue
    dragobj.otemp.style.width=$("m"+i).offsetWidth
    elm.style.width = $("m"+i).offsetWidth;
    //1为下移，2为上移
    if(b==1){
      $("m"+i).parentNode.insertBefore(dragobj.otemp,$("m"+i))
    }else{
      if($("m"+i).nextSibling==null){
        $("m"+i).parentNode.appendChild(dragobj.otemp)
      }else{
        $("m"+i).parentNode.insertBefore(dragobj.otemp,$("m"+i).nextSibling)
      }
    }
    return
  }
  for(var j=0;j<3;j++){
    if($("dom"+j).innerHTML.inc("div")||$("dom"+j).innerHTML.inc("DIV"))
      continue
    var op=getxy($("dom"+j))
    if(e.x>(op[1]+10) && e.x<(op[1]+op[2]-10)){
      $("dom"+j).appendChild(dragobj.otemp)
      dragobj.otemp.style.width=(op[2]-10)+"px"
    }
  }
}
function add_div()
{
  var o=document.createElement("div")
  o.className="mo"
  o.id="m"+domid
  $('dom0').appendChild(o)
  o.innerHTML="<h1 id="dom-domid">dom"+domid+"</h1><div class=nr></div>"
  o.getElementsByTagName("h1")[0].onmousedown=addevent
  domid++
}
</script>
</head>
<body>
<INPUT TYPE="button" value="添加一个新的DIV层" onclick="add_div();">
<div class=content>
  <div class=left id=dom0>
    <div class=mo id=m0>
      <h1 id="dom">dom0</h1>
      <div class="nr"></div>
    </div>
    <div class=mo id=m1>
      <h1 id="dom">dom1</h1><div class="nr"></div>
    </div>
    <div class=mo id=m2><h1 id="dom">dom2</h1><div class="nr"></div></div>
    <div class=mo id=m3><h1 id="dom">dom3</h1><div class="nr"></div></div>
  </div>
  <div class=center id=dom1>
    <div class=mo id=m4><h1 id="dom">dom4</h1><div class="nr"></div></div>
    <div class=mo id=m5><h1 id="dom">dom5</h1><div class="nr"></div></div>
  </div>
  <div class=right id=dom2>
    <div class=mo id=m8><h1 id="dom">dom8</h1><div class="nr"></div></div>
    <div class=mo id=m9><h1 id="dom">dom9</h1><div class="nr"></div></div>
  </div>
</div>
</body>
</html>

I hope this article will be helpful to everyone’s JavaScript programming design.

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