This article mainly introduces various mouse drag-and-drop effects implemented by JavaScript, and involves related techniques for JavaScript to dynamically transform page element attributes in response to mouse events. It has certain reference value. Friends who need it can refer to it. The details are as follows:
This is a JavaScript mouse drag and drop effect code. Through this example, you can learn about the trigger object, set the range limit, specify the container size, lock it horizontally and vertically, and also include acquiring and releasing focus, etc.
A screenshot of the running effect is as follows:
The online demo address is as follows:
http://demo.jb51.net/ js/2015/js-mouse-move-fix-style-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=gb2312" />
<title>拖放效果</title>
</head>
<body>
<script>
var isIE = (document.all) ? true : false;
var $ = function (id) {
return "string" == typeof id ? document.getElementById(id) : id;
};
var Class = {
create: function() {
return function() { this.initialize.apply(this, arguments); }
}
}
var Extend = function(destination, source) {
for (var property in source) {
destination[property] = source[property];
}
}
var Bind = function(object, fun) {
return function() {
return fun.apply(object, arguments);
}
}
var BindAsEventListener = function(object, fun) {
return function(event) {
return fun.call(object, (event || window.event));
}
}
var CurrentStyle = function(element){
return element.currentStyle || document.defaultView.getComputedStyle(element, null);
}
function addEventHandler(oTarget, sEventType, fnHandler) {
if (oTarget.addEventListener) {
oTarget.addEventListener(sEventType, fnHandler, false);
} else if (oTarget.attachEvent) {
oTarget.attachEvent("on" + sEventType, fnHandler);
} else {
oTarget["on" + sEventType] = fnHandler;
}
};
function removeEventHandler(oTarget, sEventType, fnHandler) {
if (oTarget.removeEventListener) {
oTarget.removeEventListener(sEventType, fnHandler, false);
} else if (oTarget.detachEvent) {
oTarget.detachEvent("on" + sEventType, fnHandler);
} else {
oTarget["on" + sEventType] = null;
}
};
//拖放程序
var Drag = Class.create();
Drag.prototype = {
//拖放对象
initialize: function(drag, options) {
this.Drag = $(drag);//拖放对象
this._x = this._y = 0;//记录鼠标相对拖放对象的位置
this._marginLeft = this._marginTop = 0;//记录margin
//事件对象(用于绑定移除事件)
this._fM = BindAsEventListener(this, this.Move);
this._fS = Bind(this, this.Stop);
this.SetOptions(options);
this.Limit = !!this.options.Limit;
this.mxLeft = parseInt(this.options.mxLeft);
this.mxRight = parseInt(this.options.mxRight);
this.mxTop = parseInt(this.options.mxTop);
this.mxBottom = parseInt(this.options.mxBottom);
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 = $(this.options.Handle) || this.Drag;
this._mxContainer = $(this.options.mxContainer) || null;
this.Drag.style.position = "absolute";
//透明
if(isIE && !!this.options.Transparent){
//填充拖放对象
with(this._Handle.appendChild(document.createElement("p")).style){
width = height = "100%"; backgroundColor = "#fff"; filter = "alpha(opacity:0)";
}
}
//修正范围
this.Repair();
addEventHandler(this._Handle, "mousedown", BindAsEventListener(this, this.Start));
},
//设置默认属性
SetOptions: function(options) {
this.options = {//默认值
Handle: "",//设置触发对象（不设置则使用拖放对象）
Limit: false,//是否设置范围限制(为true时下面参数有用,可以是负数)
mxLeft: 0,//左边限制
mxRight: 9999,//右边限制
mxTop: 0,//上边限制
mxBottom: 9999,//下边限制
mxContainer: "",//指定限制在容器内
LockX: false,//是否锁定水平方向拖放
LockY: false,//是否锁定垂直方向拖放
Lock: false,//是否锁定
Transparent: false,//是否透明
onStart: function(){},//开始移动时执行
onMove: function(){},//移动时执行
onStop: function(){}//结束移动时执行
};
Extend(this.options, options || {});
},
//准备拖动
Start: function(oEvent) {
if(this.Lock){ return; }
this.Repair();
//记录鼠标相对拖放对象的位置
this._x = oEvent.clientX - this.Drag.offsetLeft;
this._y = oEvent.clientY - this.Drag.offsetTop;
//记录margin
this._marginLeft = parseInt(CurrentStyle(this.Drag).marginLeft) || 0;
this._marginTop = parseInt(CurrentStyle(this.Drag).marginTop) || 0;
//mousemove时移动 mouseup时停止
addEventHandler(document, "mousemove", this._fM);
addEventHandler(document, "mouseup", this._fS);
if(isIE){
//焦点丢失
addEventHandler(this._Handle, "losecapture", this._fS);
//设置鼠标捕获
this._Handle.setCapture();
}else{
//焦点丢失
addEventHandler(window, "blur", this._fS);
//阻止默认动作
oEvent.preventDefault();
};
//附加程序
this.onStart();
},
//修正范围
Repair: function() {
if(this.Limit){
//修正错误范围参数
this.mxRight = Math.max(this.mxRight, this.mxLeft + this.Drag.offsetWidth);
this.mxBottom = Math.max(this.mxBottom, this.mxTop + this.Drag.offsetHeight);
//如果有容器必须设置position为relative来相对定位，并在获取offset之前设置
!this._mxContainer || CurrentStyle(this._mxContainer).position == "relative" || (this._mxContainer.style.position = "relative");
}
},
//拖动
Move: function(oEvent) {
//判断是否锁定
if(this.Lock){ this.Stop(); return; };
//清除选择
window.getSelection ? window.getSelection().removeAllRanges() : document.selection.empty();
//设置移动参数
var iLeft = oEvent.clientX - this._x, iTop = oEvent.clientY - this._y;
//设置范围限制
if(this.Limit){
//设置范围参数
var mxLeft = this.mxLeft, mxRight = this.mxRight, mxTop = this.mxTop, mxBottom = this.mxBottom;
//如果设置了容器，再修正范围参数
if(!!this._mxContainer){
mxLeft = Math.max(mxLeft, 0);
mxTop = Math.max(mxTop, 0);
mxRight = Math.min(mxRight, this._mxContainer.clientWidth);
mxBottom = Math.min(mxBottom, this._mxContainer.clientHeight);
};
//修正移动参数
iLeft = Math.max(Math.min(iLeft, mxRight - this.Drag.offsetWidth), mxLeft);
iTop = Math.max(Math.min(iTop, mxBottom - this.Drag.offsetHeight), mxTop);
}
//设置位置，并修正margin
if(!this.LockX){ this.Drag.style.left = iLeft - this._marginLeft + "px"; }
if(!this.LockY){ this.Drag.style.top = iTop - this._marginTop + "px"; }
//附加程序
this.onMove();
},
//停止拖动
Stop: function() {
//移除事件
removeEventHandler(document, "mousemove", this._fM);
removeEventHandler(document, "mouseup", this._fS);
if(isIE){
removeEventHandler(this._Handle, "losecapture", this._fS);
this._Handle.releaseCapture();
}else{
removeEventHandler(window, "blur", this._fS);
};
//附加程序
this.onStop();
}
};
</script>
<style>
#idContainer{ border:10px solid #990000; width:600px; height:300px;}
#idDrag{ border:5px solid #C4E3FD; background:#C4E3FD; width:50px; height:50px; top:50px; left:50px;}
#idHandle{cursor:move; height:25px; background:#0000FF; overflow:hidden;}
</style>
<p id="idContainer">
<p id="idDrag"><p id="idHandle"></p></p>
</p>
<input id="idReset" type="button" value="复位" />
<input id="idLock" type="button" value="锁定" />
<input id="idLockX" type="button" value="锁定水平" />
<input id="idLockY" type="button" value="锁定垂直" />
<input id="idLimit" type="button" value="范围锁定" />
<input id="idLimitOff" type="button" value="取消范围锁定" />
<br />拖放状态：<span id="idShow">未开始</span>
<script>
var drag = new Drag("idDrag", { mxContainer: "idContainer", Handle: "idHandle", Limit: true,
onStart: function(){ $("idShow").innerHTML = "开始拖放"; },
onMove: function(){ $("idShow").innerHTML = "left："+this.Drag.offsetLeft+"；top:"+this.Drag.offsetTop; },
onStop: function(){ $("idShow").innerHTML = "结束拖放"; }
});
$("idReset").onclick = function(){
drag.Limit = true;
drag.mxLeft = drag.mxTop = 0;
drag.mxRight = drag.mxBottom = 9999;
drag.LockX = drag.LockY = drag.Lock = false;
}
$("idLock").onclick = function(){ drag.Lock = true; }
$("idLockX").onclick = function(){ drag.LockX = true; }
$("idLockY").onclick = function(){ drag.LockY = true; }
$("idLimit").onclick = function(){ drag.mxRight = drag.mxBottom = 200;drag.Limit = true; }
$("idLimitOff").onclick = function(){ drag.Limit = false; }
</script>
</body>
</html>The above is the entire content of this chapter. For more related tutorials, please Visit JavaScript Video Tutorial!
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