JS实现多Div模块拖拽功能

空闲时间，同事让帮忙整个JS拖拽div模块功能。于是便在网上搜索，总结如下一个可实现多div模块拖拽的功能。一下是整体的HTML代码，
里边可以控制到拖拽开始（onStart），拖拽时候（onMove），拖拽结束（onStop）三个时候的准确状态值及坐标
<!DOCTYPE>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>拖拽库</title>
<style type="text/css">
	div,h2,p{margin:0;padding:0;}
	body{font:14px/1.5 arial;}
	#box{100px;height:100px;background:#fef4eb;padding:5px;margin:50px;border:1px solid #f60;}
	#box .title{height:25px;background:#f60;}
	#box2{100px;height:100px;background:#fef4eb;padding:5px;margin:100px;border:1px solid #f60;}
	#box2 .title{height:25px;background:#f60;}
	#tool{margin-bottom:10px;}
</style>
<script type="text/javascript">
function Drag()
{
	 //初始化
	 this.initialize.apply(this, arguments)
}
Drag.prototype = {
 //初始化
 initialize : function (drag, options)
 {
	 this.drag = this.$(drag);
	 this._x = this._y = 0;
	 this._moveDrag = this.bind(this, this.moveDrag);
	 this._stopDrag = this.bind(this, this.stopDrag);
	 
	 this.setOptions(options);
	 
	 this.handle = this.$(this.options.handle);
	 this.maxContainer = this.$(this.options.maxContainer);
	 
	 this.maxTop = Math.max(this.maxContainer.clientHeight, this.maxContainer.scrollHeight) - this.drag.offsetHeight;
	 this.maxLeft = Math.max(this.maxContainer.clientWidth, this.maxContainer.scrollWidth) - this.drag.offsetWidth;
	 
	 this.limit = this.options.limit;
	 this.lockX = this.options.lockX;
	 this.lockY = this.options.lockY;
	 this.lock = this.options.lock;
	 
	 this.onStart = this.options.onStart;
	 this.onMove = this.options.onMove;
	 this.onStop = this.options.onStop;
	 
	 this.handle.style.cursor = "move";
	 
	 this.changeLayout();
	 
	 this.addHandler(this.handle, "mousedown", this.bind(this, this.startDrag))
 },
 changeLayout : function ()
 {
	 this.drag.style.top = this.drag.offsetTop + "px";
	 this.drag.style.left = this.drag.offsetLeft + "px";
	 this.drag.style.position = "absolute";
	 this.drag.style.margin = "0"
 },
	startDrag : function (event)
 { 
	 var event = event || window.event;
	 
	 this._x = event.clientX - this.drag.offsetLeft;
	 this._y = event.clientY - this.drag.offsetTop;
	 
	 this.addHandler(document, "mousemove", this._moveDrag);
	 this.addHandler(document, "mouseup", this._stopDrag);
	 
	 event.preventDefault && event.preventDefault();
	 this.handle.setCapture && this.handle.setCapture();
	 
	 this.onStart()
 },
 moveDrag : function (event)
 {
	 var event = event || window.event;
	 
	 var iTop = event.clientY - this._y;
	 var iLeft = event.clientX - this._x;
	 
	 if (this.lock) return;
	 
	 this.limit && (iTop < 0 && (iTop = 0), iLeft < 0 && (iLeft = 0), iTop > this.maxTop && (iTop = this.maxTop), iLeft > this.maxLeft && (iLeft = this.maxLeft));
	 
	 this.lockY || (this.drag.style.top = iTop + "px");
	 this.lockX || (this.drag.style.left = iLeft + "px");
	 
	 event.preventDefault && event.preventDefault();
	 
	 this.onMove()
 },
 stopDrag : function ()
 {
	 this.removeHandler(document, "mousemove", this._moveDrag);
	 this.removeHandler(document, "mouseup", this._stopDrag);
	 
	 this.handle.releaseCapture && this.handle.releaseCapture();
	 
	 this.onStop()
 },
 //参数设置
 setOptions : function (options){
	this.options = {
	  handle:  this.drag, //事件对象
	  limit:  true, //锁定范围
	  lock:  false, //锁定位置
	  lockX:  false, //锁定水平位置
	  lockY:  false, //锁定垂直位置
	  maxContainer: document.documentElement || document.body, //指定限制容器
	  onStart: function () {}, //开始时回调函数
	  onMove:  function () {}, //拖拽时回调函数
	  onStop:  function () {} //停止时回调函数
	};
	for (var p in options) this.options[p] = options[p]
 },
 //获取id
 $ : function (id){
		return typeof id === "string" ? document.getElementById(id) : id
  },
 //添加绑定事件
 addHandler : function (oElement, sEventType, fnHandler) {
	 return oElement.addEventListener ? oElement.addEventListener(sEventType, fnHandler, false) : oElement.attachEvent("on" + sEventType, fnHandler)
 },
 //删除绑定事件
 removeHandler : function (oElement, sEventType, fnHandler) {
	return oElement.removeEventListener ? oElement.removeEventListener(sEventType, fnHandler, false) : oElement.detachEvent("on" + sEventType, fnHandler)
 },
 //绑定事件到对象
 bind : function (object, fnHandler) {
	return function () {
		return fnHandler.apply(object, arguments) 
		}
	}
};
  
  
//应用
window.onload = function (){
	 var oBox = document.getElementById("box"); 
	 var oTitle = oBox.getElementsByTagName("h2")[0];
	 var oSpan = document.getElementsByTagName("span")[0];
	 var oDrag = new Drag(oBox, {handle:oTitle, limit:false});
	 
	 
	 var oBox2 = document.getElementById("box2"); 
	 var oTitle2 = oBox2.getElementsByTagName("h2")[0];
	 var oSpan2 = document.getElementsByTagName("span")[0];
	 var oDrag2 = new Drag(oBox2, {handle:oTitle2, limit:false});
	 
	 
	 var aInput = document.getElementsByTagName("input");
 
	 //锁定范围接口
	 aInput[0].onclick = function (){
		 oDrag.limit = !oDrag.limit;
		 this.value = oDrag.limit ? "取消锁定范围" : "锁定范围"
	 };
 
	 //水平锁定接口
	 aInput[1].onclick = function () {
		 oDrag.lockX = !oDrag.lockX;
		 this.value = oDrag.lockX ? "取消水平锁定" : "水平锁定"
	 };
 
	 //垂直锁定接口
	 aInput[2].onclick = function (){
		 oDrag.lockY = !oDrag.lockY;
		 this.value = oDrag.lockY ? "取消垂直锁定" : "垂直锁定"
	 };
 
	 //锁定位置接口
	 aInput[3].onclick = function () {
		 oDrag.lock = !oDrag.lock;
		 this.value = oDrag.lock ? "取消锁定位置" : "锁定位置"
	 };
 
	 //开始拖拽时方法
	 oDrag.onStart = function ()  {
		oSpan.innerHTML = "开始拖拽" 
	 };
 
	 //开始拖拽时方法
	 oDrag.onMove = function () {
		oSpan.innerHTML = "left:" + this.drag.offsetLeft + ", top:" + this.drag.offsetTop 
	 };
	 
	 //结束拖拽时方法
	 oDrag.onStop = function () {
		oSpan.innerHTML = "结束拖拽了" 
	 };
};
</script>
</head>
<body>
	<div id="tool">
		  <input type="button" value="锁定范围" />
		  <input type="button" value="水平锁定" />
		  <input type="button" value="垂直锁定" />
		  <input type="button" value="锁定位置" />
	</div>
	<p>拖放状态：<span>未开始</span></p>
	<div id="box"> 
		<h2 class="title">我是第一个模块</h2>
	</div>

	<div id="box2"> 
	 <h2 class="title">我是第二个模块</h2>
	</div>
</body>
</html>
　　以后还会更新...