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) {
  var args = Array.prototype.slice.call(arguments).slice(2);
  return function() {
    return fun.apply(object, args);
  }
}

var BindAsEventListener = function(object, fun) {
  return function(event) {
    return fun.call(object, Event(event));
  }
}

function Event(e){
  var oEvent = isIE ? window.event : e;
  if (isIE) {
    oEvent.pageX = oEvent.clientX + document.documentElement.scrollLeft;
    oEvent.pageY = oEvent.clientY + document.documentElement.scrollTop;
    oEvent.preventDefault = function () { this.returnValue = false; };
    oEvent.detail = oEvent.wheelDelta / (-40);
    oEvent.stopPropagation = function(){ this.cancelBubble = true; }; 
  }
  return oEvent;
}

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;
    }
};


//滑动条程序
var Slider = Class.create();
Slider.prototype = {
  //容器对象，滑块
  initialize: function(container, bar, options) {
  this.Bar = $$(bar);
  this.Container = $$(container);
  this._timer = null;//自动滑移的定时器
  this._ondrag = false;//解决ie的click问题
  //是否最小值、最大值、中间值
  this._IsMin = this._IsMax = this._IsMid = false;
  //实例化一个拖放对象，并限定范围
  this._drag = new Drag(this.Bar, { Limit: true, mxContainer: this.Container,
    onStart: Bind(this, this.DragStart), onStop: Bind(this, this.DragStop), onMove: Bind(this, this.Move)
  });
  
  this.SetOptions(options);
  
  this.WheelSpeed = Math.max(0, this.options.WheelSpeed);
  this.KeySpeed = Math.max(0, this.options.KeySpeed);
  
  this.MinValue = this.options.MinValue;
  this.MaxValue = this.options.MaxValue;

  
  this.RunTime = Math.max(1, this.options.RunTime);
  this.RunStep = Math.max(1, this.options.RunStep);
  
  this.Ease = !!this.options.Ease;
  this.EaseStep = Math.max(1, this.options.EaseStep);
  
  this.onMin = this.options.onMin;
  this.onMax = this.options.onMax;
  this.onMid = this.options.onMid;
  
  this.onDragStart = this.options.onDragStart;
  this.onDragStop = this.options.onDragStop;
  
  this.onMove = this.options.onMove;
  
  this._horizontal = !!this.options.Horizontal;//一般不允许修改
  
  //锁定拖放方向
  this._drag[this._horizontal ? "LockY" : "LockX"] = true;
  
  //点击控制
  addEventHandler(this.Container, "click", BindAsEventListener(this, function(e){ this._ondrag || this.ClickCtrl(e);}));
  //取消冒泡，防止跟Container的click冲突
  addEventHandler(this.Bar, "click", BindAsEventListener(this, function(e){ e.stopPropagation(); }));
  
  //设置鼠标滚轮控制
  this.WheelBind(this.Container);
  //设置方向键控制
  this.KeyBind(this.Container);
  //修正获取焦点
  var oFocus = isIE ? (this.KeyBind(this.Bar), this.Bar) : this.Container;
  addEventHandler(this.Bar, "mousedown", function(){ oFocus.focus(); });
  //ie鼠标捕获和ff的取消默认动作都不能获得焦点，所以要手动获取
  //如果ie把focus设置到Container，那么在出现滚动条时ie的focus可能会导致自动滚屏
  },
  //设置默认属性
  SetOptions: function(options) {
  this.options = {//默认值
    MinValue:  0,//最小值
    MaxValue:  100,//最大值
    WheelSpeed: 5,//鼠标滚轮速度,越大越快(0则取消鼠标滚轮控制)
    KeySpeed:   50,//方向键滚动速度,越大越慢(0则取消方向键控制)
    Horizontal:  true,//是否水平滑动
    RunTime:  20,//自动滑移的延时时间,越大越慢
    RunStep:  2,//自动滑移每次滑动的百分比
    Ease:    true,//是否缓动
    EaseStep:  5,//缓动等级,越大越慢
    onMin:    function(){},//最小值时执行
    onMax:    function(){},//最大值时执行
    onMid:    function(){},//中间值时执行
    onDragStart:function(){},//拖动开始时执行
    onDragStop:  function(){},//拖动结束时执行
    onMove:    function(){}//滑动时执行
  };
  Extend(this.options, options || {});
  },
  //开始拖放滑动
  DragStart: function() {
    this.Stop();
  this.onDragStart();
  this._ondrag = true;
  },
  //结束拖放滑动
  DragStop: function() {
    this.onDragStop();
  setTimeout(Bind(this, function(){ this._ondrag = false; }), 10);
  },
  //滑动中
  Move: function() {
    this.onMove();
  
  var percent = this.GetPercent();
  //最小值判断
  if(percent > 0){
    this._IsMin = false;
  }else{
    if(!this._IsMin){ this.onMin(); this._IsMin = true; }
  }
  //最大值判断
  if(percent < 1){
    this._IsMax = false;
  }else{
    if(!this._IsMax){ this.onMax(); this._IsMax = true; }
  }
  //中间值判断
  if(percent > 0 && percent < 1){
    if(!this._IsMid){ this.onMid(); this._IsMid = true; }
  }else{
    this._IsMid = false;
  }
  },
  //鼠标点击控制
  ClickCtrl: function(e) {
  var o = this.Container, iLeft = o.offsetLeft, iTop = o.offsetTop;
  while (o.offsetParent) { o = o.offsetParent; iLeft += o.offsetLeft; iTop += o.offsetTop; }
  //考虑有滚动条，要用pageX和pageY
  this.EasePos(e.pageX - iLeft - this.Bar.offsetWidth / 2, e.pageY - iTop - this.Bar.offsetHeight / 2);
  },
  //鼠标滚轮控制
  WheelCtrl: function(e) {
  var i = this.WheelSpeed * e.detail;
  this.SetPos(this.Bar.offsetLeft + i, this.Bar.offsetTop + i);
  //防止触发其他滚动条
  e.preventDefault();
  },
  //绑定鼠标滚轮
  WheelBind: function(o) {
    //鼠标滚轮控制
  addEventHandler(o, isIE ? "mousewheel" : "DOMMouseScroll", BindAsEventListener(this, this.WheelCtrl));
  },
  //方向键控制
  KeyCtrl: function(e) {
  if(this.KeySpeed){
    var iLeft = this.Bar.offsetLeft, iWidth = (this.Container.clientWidth - this.Bar.offsetWidth) / this.KeySpeed
      , iTop = this.Bar.offsetTop, iHeight = (this.Container.clientHeight - this.Bar.offsetHeight) / this.KeySpeed;
    //根据按键设置值
    switch (e.keyCode) {
      case 37 ://左
        iLeft -= iWidth; break;
      case 38 ://上
        iTop -= iHeight; break;
      case 39 ://右
        iLeft += iWidth; break;
      case 40 ://下
        iTop += iHeight; break;
      default :
        return;//不是方向按键返回
    }
    this.SetPos(iLeft, iTop);
    //防止触发其他滚动条
    e.preventDefault();
  }
  },
  //绑定方向键
  KeyBind: function(o) {
  addEventHandler(o, "keydown", BindAsEventListener(this, this.KeyCtrl));
  //设置tabIndex使设置对象能支持focus
  o.tabIndex = -1;
  //取消focus时出现的虚线框
  isIE || (o.style.outline = "none");
  },
  //获取当前值
  GetValue: function() {
  //根据最大最小值和滑动百分比取值
  return this.MinValue + this.GetPercent() * (this.MaxValue - this.MinValue);
  },
  //设置值位置
  SetValue: function(value) {
  //根据最大最小值和参数值设置滑块位置
  this.SetPercent((value- this.MinValue)/(this.MaxValue - this.MinValue));
  },
  //获取百分比
  GetPercent: function() {
  //根据滑动条滑块取百分比
  return this._horizontal ? this.Bar.offsetLeft / (this.Container.clientWidth - this.Bar.offsetWidth)
    : this.Bar.offsetTop / (this.Container.clientHeight - this.Bar.offsetHeight)
  },
  //设置百分比位置
  SetPercent: function(value) {
  //根据百分比设置滑块位置
  this.EasePos((this.Container.clientWidth - this.Bar.offsetWidth) * value, (this.Container.clientHeight - this.Bar.offsetHeight) * value);
  },
  //自动滑移(是否递增)
  Run: function(bIncrease) {
  this.Stop();
  //修正一下bIncrease
  bIncrease = !!bIncrease;
  //根据是否递增来设置值
  var percent = this.GetPercent() + (bIncrease ? 1 : -1) * this.RunStep / 100;
  this.SetPos((this.Container.clientWidth - this.Bar.offsetWidth) * percent, (this.Container.clientHeight - this.Bar.offsetHeight) * percent);
  //如果没有到极限值就继续滑移
  if(!(bIncrease ? this._IsMax : this._IsMin)){
    this._timer = setTimeout(Bind(this, this.Run, bIncrease), this.RunTime);
  }
  },
  //停止滑移
  Stop: function() {
  clearTimeout(this._timer);
  },
  //缓动滑移
  EasePos: function(iLeftT, iTopT) {
  this.Stop();
  //必须是整数，否则可能死循环
  iLeftT = Math.round(iLeftT); iTopT = Math.round(iTopT);
  //如果没有设置缓动
  if(!this.Ease){ this.SetPos(iLeftT, iTopT); return; }
  //获取缓动参数
  var iLeftN = this.Bar.offsetLeft, iLeftS = this.GetStep(iLeftT, iLeftN)
  , iTopN = this.Bar.offsetTop, iTopS = this.GetStep(iTopT, iTopN);
  //如果参数有值
  if(this._horizontal ? iLeftS : iTopS){
    //设置位置
    this.SetPos(iLeftN + iLeftS, iTopN + iTopS);
    //如果没有到极限值则继续缓动
    if(this._IsMid){ this._timer = setTimeout(Bind(this, this.EasePos, iLeftT, iTopT), this.RunTime); }
  }
  },
  //获取步长
  GetStep: function(iTarget, iNow) {
    var iStep = (iTarget - iNow) / this.EaseStep;
    if (iStep == 0) return 0;
    if (Math.abs(iStep) < 1) return (iStep > 0 ? 1 : -1);
    return iStep;
  },
  //设置滑块位置
  SetPos: function(iLeft, iTop) {
  this.Stop();
  this._drag.SetPos(iLeft, iTop);
  }
};

//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("div")).style){
      width = height = "100%"; backgroundColor = "#fff"; filter = "alpha(opacity:0)"; fontSize = 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" || CurrentStyle(this._mxContainer).position == "absolute" || (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
  this.SetPos(oEvent.clientX - this._x, oEvent.clientY - this._y);
  },
  //设置位置
  SetPos: function(iLeft, iTop) {
  //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();
  }
};