DIV拖动库，稳定高效，专为您解决DIV拖动的烦恼，支持多实例
此脚本不应直接安装，它是供其他脚本使用的外部库。如果您需要使用该库，请在脚本元属性加入：// @require https://update.greasyfork.icu/scripts/412159/858320/MyDrag.js
// ==UserScript==
// @name MyDrag
// @namespace http://bbs.91wc.net/
// @version 0.1.3
// @description DIV拖动库，稳定高效，专为您解决DIV拖动的烦恼，支持多实例
// @author Wilson
// ==/UserScript==
var MyDragHelper={}, MyDrag = (function(){
function Drag(){
//初始化
this.initialize.apply(this, arguments)
}
Drag.prototype = {
//初始化
initialize : function (drag, options){
this.drag = this.$(drag);
this.drag.style.width = (parseInt(this.drag.style.width)||this.drag.offsetWidth);
this._x = this._y = 0;
this._moveDrag = this.bind(this, this.moveDrag);
this._stopDrag = this.bind(this, this.stopDrag);
this.setOptions(options);
this.handle = this.$(this.options.handle);
this.left = this.options.left;
this.top = this.options.top;
this.right = this.options.right;
this.bottom = this.options.bottom;
this.position = this.options.position;
this.onlyViewport = this.options.onlyViewport;
this.maxContainer = this.$(this.options.maxContainer);
this.maxTop = Math.max(this.maxContainer.clientHeight, this.maxContainer.scrollHeight) - this.drag.offsetHeight + this.maxContainer.offsetTop;
this.maxLeft = Math.max(this.maxContainer.clientWidth, this.maxContainer.scrollWidth) - this.drag.offsetWidth + this.maxContainer.offsetLeft;
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.zIndex = this.options.zIndex;
this.alone = this.options.alone;
if(!this.alone){
MyDragHelper.zIndex = MyDragHelper.zIndex ? ++MyDragHelper.zIndex : this.zIndex;
MyDragHelper.count = MyDragHelper.count ? ++MyDragHelper.count : 1;
}
this.changeLayout();
this.addHandler(this.handle, "mousedown", this.bind(this, this.startDrag));
},
changeLayout : function (){
if(this.right){
this.drag.style.right = this.right + "px";
} else {
this.drag.style.left = (this.maxContainer.offsetLeft + this.left) + "px";
}
if(this.bottom){
this.drag.style.bottom = this.bottom + "px";
} else {
this.drag.style.top = (this.maxContainer.offsetLeft + this.top) + "px";
}
this.drag.style.position = this.position;
this.drag.style.margin = "0"
this.drag.style.zIndex = !this.alone ? MyDragHelper.zIndex : this.zIndex;
},
startDrag : function (event){
var event = event || window.event;
this._x = event.clientX - this.drag.offsetLeft;
this._y = event.clientY - this.drag.offsetTop;
if(!this.alone && MyDragHelper.count > 1) this.drag.style.zIndex = ++MyDragHelper.zIndex;
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;
if(this.limit){
if(iTop < this.maxContainer.offsetTop) iTop = this.maxContainer.offsetTop;
if(iLeft < this.maxContainer.offsetLeft) iLeft = this.maxContainer.offsetLeft;
if(iTop > this.maxTop) iTop = this.maxTop;
if(iLeft > this.maxLeft) iLeft = this.maxLeft;
}
this.lockY || (this.drag.style.top = iTop + "px");
this.lockX || (this.drag.style.left = iLeft + "px");
var iWinWidth = this.onlyViewport ? document.documentElement.clientWidth : this.maxContainer.offsetLeft + this.maxContainer.offsetWidth;
var iWinHeight = this.onlyViewport ? document.documentElement.clientHeight : this.maxContainer.offsetTop + this.maxContainer.offsetHeight;
if(this.drag.offsetLeft<0){
this.drag.style.left =0+'px';
}else if(this.drag.offsetLeft>(iWinWidth-this.drag.offsetWidth)){
this.drag.style.left =iWinWidth-this.drag.offsetWidth+'px';
}
if(this.drag.offsetTop<0){
this.drag.style.top =0+'px';
}else if(this.drag.offsetTop>(iWinHeight-this.drag.offsetHeight)){
this.drag.style.top =iWinHeight-this.drag.offsetHeight+'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){
var thisDragCssZIndex = window.getComputedStyle(this.drag,null).zIndex;
thisDragCssZIndex = isNaN(thisDragCssZIndex) ? 0 : thisDragCssZIndex;
this.options ={
handle: this.drag, //事件对象
top: 0, //默认顶部位置
bottom: 0, //默认底部位置，不支持非body的限定容器
left: 0, //默认左边位置
right: 0, //默认右边位置，不支持非body的限定容器
position: 'absolute', //默认浮动方式
onlyViewport: true, //仅在视窗内拖动
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
zIndex: this.drag.style.zIndex || thisDragCssZIndex || 999999999, //z轴高度
alone: false //是否孤立的，为了防止拖动目标覆盖，默认会和其他拖动层的zIndex相互增加高度
};
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)
}
}
};
return Drag;
})();
/**
//使用示例：
//这里样式仅仅为了演示好看，实际上只需要设置box宽度就好了,如果没设置宽度，div默认100%，不利于看到效果
body,div,h2,p{margin:0;padding:0}
body{font:14px/1.5 arial}
#box{width:300px;height:100px;background:#fef4eb;padding:5px;border:1px solid #666}
#box #title{height:25px;background:#ccc;display:inline-block;cursor:move;width:100%;text-align:center}
.content{text-align:center;line-height:50px}
<div id="box">
<span id="title">按下我拖拽</span>
<div class='content'>内容区</div>
</div>
//调用
var box = document.getElementById("box");
var title = document.getElementById("title");
new MyDrag(box, {handle:title});
//box是拖拽最外层的div，title是按下时控制句柄的div
//其他参数
handle: //拖动控制句柄，就是上面示例的title
limit: //是否限制拖动范围，默认是true
maxContainer: //拖动限制范围的容器，默认是body，可设置在某个div内拖动
top: //顶部位置,默认0
bottom: 0, //默认底部位置，不支持非body的限定容器
left: //左边位置,默认0
right: 0, //默认右边位置，不支持非body的限定容器
position: 'absolute', //默认浮动方式
onlyViewport: //是否仅在视窗内拖动，默认true
lock: //是否锁定位置，默认false，锁定后无法拖动
lockX: //是否锁定水平位置，默认false，锁定后只能y轴拖动
lockY: //是否锁定垂直位置，默认false，锁定后只能x轴拖动
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
zIndex: 可以设置z轴高度，默认会先读取内联样式的设置，再读取css样式设置，都无则是999999999
alone: 是否孤立的，为了防止拖动目标覆盖，默认会和其他拖动层的zIndex相互增加高度
*/