JS drag and drop library example based on object-oriented implementation

JS drag and drop library example based on object-oriented implementation_javascript skills

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Release： 2016-05-16 15:37:59

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The example in this article describes the JS-based object-oriented drag and drop library. Share it with everyone for your reference. The details are as follows:

This is an object-oriented JS drag and drop library that can set horizontal locking, vertical locking, locking position, locking range, etc. After setting these ranges, dragging can only be done in the set mode. I think this is Pretty good drag and drop example.

The screenshot of the running effect is as follows:

The online demo address is as follows:

http://demo.jb51.net/js/2015/js-mxdx-draw-plug-codes/

The specific code is as follows:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<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{width:100px;height:100px;background:#fef4eb;padding:5px;margin:50px;border:1px solid #f60;}
#box .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" &#63; document.getElementById(id) : id
 },
 //添加绑定事件
 addHandler : function (oElement, sEventType, fnHandler)
 {
  return oElement.addEventListener &#63; oElement.addEventListener(sEventType, fnHandler, false) : oElement.attachEvent("on" + sEventType, fnHandler)
 },
 //删除绑定事件
 removeHandler : function (oElement, sEventType, fnHandler)
 {
  return oElement.removeEventListener &#63; 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 aInput = document.getElementsByTagName("input");
 //锁定范围接口
 aInput[0].onclick = function ()
 {
  oDrag.limit = !oDrag.limit;
  this.value = oDrag.limit &#63; "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 &#63; "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 &#63; "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 &#63; "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
 };
 //开始拖拽时方法
 oDrag.onStop = function ()
 {
  oSpan.innerHTML = "结束拖拽"
 };
};
</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"></h2>
</div>
</body>
</html>

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