var $$ = function (id) {
 return "string" == typeof id ? document.getElementById(id) : id;
};

var Extend = function(destination, source) {
 for (var property in source) {
  destination[property] = source[property];
 }
 return destination;
}

var CurrentStyle = function(element){
 return element.currentStyle || document.defaultView.getComputedStyle(element, null);
}

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

var Tween = {
	Quint: {
		easeIn: function(t,b,c,d){
			return c*(t/=d)*t*t*t*t + b;
		},
		easeOut: function(t,b,c,d){
			return c*((t=t/d-1)*t*t*t*t + 1) + b;
		},
		easeInOut: function(t,b,c,d){
			if ((t/=d/2) < 1) return c/2*t*t*t*t*t + b;
			return c/2*((t-=2)*t*t*t*t + 2) + b;
		}
	}
}


//瀹瑰櫒瀵硅薄,婊戝姩瀵硅薄,鍒囨崲鏁伴噺
var SlideTrans = function(index_features, slider, count, options) {
 this._slider = $$(slider);
 this._index_features = $$(index_features);//瀹瑰櫒瀵硅薄
 this._timer = null;//瀹氭椂鍣?
 this._count = Math.abs(count);//鍒囨崲鏁伴噺
 this._target = 0;//鐩爣鍊?
 this._t = this._b = this._c = 0;//tween鍙傛暟
 
 this.Index = 0;//褰撳墠绱㈠紩
 
 this.SetOptions(options);
 
 this.Auto = !!this.options.Auto;
 this.Duration = Math.abs(this.options.Duration);
 this.Time = Math.abs(this.options.Time);
 this.Pause = Math.abs(this.options.Pause);
 this.Tween = this.options.Tween;
 this.onStart = this.options.onStart;
 this.onFinish = this.options.onFinish;
 
 var bVertical = !!this.options.Vertical;
 this._css = bVertical ? "top" : "left";//鏂瑰悜
 
 //鏍峰紡璁剧疆
 var p = CurrentStyle(this._index_features).position;
 p == "relative" || p == "absolute" || (this._index_features.style.position = "relative");
 this._index_features.style.overflow = "hidden";
 this._slider.style.position = "absolute";
 
 this.Change = this.options.Change ? this.options.Change :
  this._slider[bVertical ? "offsetHeight" : "offsetWidth"] / this._count;
};
SlideTrans.prototype = {
  //璁剧疆榛樿灞炴€?
  SetOptions: function(options) {
 this.options = {//榛樿鍊?
  Vertical: true,//鏄惁鍨傜洿鏂瑰悜锛堟柟鍚戜笉鑳芥敼锛?
  Auto:  true,//鏄惁鑷姩
  Change:  0,//鏀瑰彉閲?
  Duration: 60,//婊戝姩鎸佺画鏃堕棿
  Time:  10,//婊戝姩寤舵椂
  Pause:  4000,//鍋滈】鏃堕棿(Auto涓簍rue鏃舵湁鏁?
  onStart: function(){},//寮€濮嬭浆鎹㈡椂鎵ц
  onFinish: function(){},//瀹屾垚杞崲鏃舵墽琛?
  Tween:  Tween.Quint.easeOut//tween绠楀瓙
 };
 Extend(this.options, options || {});
  },
  //寮€濮嬪垏鎹?
  Run: function(index) {
 //淇index
 index == undefined && (index = this.Index);
 index < 0 && (index = this._count - 1) || index >= this._count && (index = 0);
 //璁剧疆鍙傛暟
 this._target = -Math.abs(this.Change) * (this.Index = index);
 this._t = 0;
 this._b = parseInt(CurrentStyle(this._slider)[this.options.Vertical ? "top" : "left"]);
 this._c = this._target - this._b;
 
 this.onStart();
 this.Move();
  },
  //绉诲姩
  Move: function() {
 clearTimeout(this._timer);
 //鏈埌杈剧洰鏍囩户缁Щ鍔ㄥ惁鍒欒繘琛屼笅涓€娆℃粦鍔?
 if (this._c && this._t < this.Duration) {
  this.MoveTo(Math.round(this.Tween(this._t++, this._b, this._c, this.Duration)));
  this._timer = setTimeout(Bind(this, this.Move), this.Time);
 }else{
  this.MoveTo(this._target);
  this.Auto && (this._timer = setTimeout(Bind(this, this.Next), this.Pause));
 }
  },
  //绉诲姩鍒?
  MoveTo: function(i) {
 this._slider.style[this._css] = i + "px";
  },
  //涓嬩竴涓?
  Next: function() {
 this.Run(++this.Index);
  },
  //涓婁竴涓?
  Previous: function() {
this.Index=this.Index-1;
 this.Run( this.Index);
  },
  //鍋滄
  Stop: function() {
 clearTimeout(this._timer); this.MoveTo(this._target);
  }
};