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 = {

	Quart: {

		easeOut: function(t,b,c,d){

			return -c * ((t=t/d-1)*t*t*t - 1) + b;

		}

	},

	Back: {

		easeOut: function(t,b,c,d,s){

			if (s == undefined) s = 1.70158;

			return c*((t=t/d-1)*t*((s+1)*t + s) + 1) + b;

		}

	},

	Bounce: {

		easeOut: function(t,b,c,d){

			if ((t/=d) < (1/2.75)) {

				return c*(7.5625*t*t) + b;

			} else if (t < (2/2.75)) {

				return c*(7.5625*(t-=(1.5/2.75))*t + .75) + b;

			} else if (t < (2.5/2.75)) {

				return c*(7.5625*(t-=(2.25/2.75))*t + .9375) + b;

			} else {

				return c*(7.5625*(t-=(2.625/2.75))*t + .984375) + b;

			}

		}

	}

}





//容器对象,滑动对象,切换数量

var SlideTrans = function(container, slider, count, options) {

	this._slider = $(slider);

	this._container = $(container);//容器对象

	this._timer = null;//定时器

	this._count = Math.abs(count);//切换数量

	this._target = 0;//目标值

	this._t = this._b = this._c = 0;//tween参数

	

	this.Index = 0;//当前索引

	

	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";//方向

	

	//样式设置

	var p = CurrentStyle(this._container).position;

	p == "relative" || p == "absolute" || (this._container.style.position = "relative");

	this._container.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 = {

  //设置默认属性

  SetOptions: function(options) {

	this.options = {//默认值

		Vertical:	true,//是否垂直方向（方向不能改）

		Auto:		true,//是否自动

		Change:		0,//改变量

		Duration:	100,//滑动持续时间

		Time:		10,//滑动延时

		Pause:		4000,//停顿时间(Auto为true时有效)

		onStart:	function(){},//开始转换时执行

		onFinish:	function(){},//完成转换时执行

		Tween:		Tween.Quart.easeOut//tween算子

	};

	Extend(this.options, options || {});

  },

  //开始切换

  Run: function(index) {

	//修正index

	index == undefined && (index = this.Index);

	index < 0 && (index = this._count - 1) || index >= this._count && (index = 0);

	//设置参数

	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();

  },

  //移动

  Move: function() {

	clearTimeout(this._timer);

	//未到达目标继续移动否则进行下一次滑动

	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));

	}

  },

  //移动到

  MoveTo: function(i) {

	this._slider.style[this._css] = i + "px";

  },

  //下一个

  Next: function() {

	this.Run(++this.Index);

  },

  //上一个

  Previous: function() {

	this.Run(--this.Index);

  },

  //停止

  Stop: function() {

	clearTimeout(this._timer); this.MoveTo(this._target);

  }

}



var forEach = function(array, callback, thisObject){

		if(array.forEach){

			array.forEach(callback, thisObject);

		}else{

			for (var i = 0, len = array.length; i < len; i++) { callback.call(thisObject, array[i], i, array); }

		}

	}

	

	var st = new SlideTrans("idContainer2", "idSlider2", 4, { Vertical: false });

	

	var nums = [];

	//插入数字

	for(var i = 0, n = st._count - 1; i <= n;){

		(nums[i] = $("idNum").appendChild(document.createElement("li"))).innerHTML = ++i;

	}

	

	forEach(nums, function(o, i){

		o.onmouseover = function(){ o.className = "on"; st.Auto = false; st.Run(i); }

		o.onmouseout = function(){ o.className = ""; st.Auto = true; st.Run(); }

	})

	

	//设置按钮样式

	st.onStart = function(){

		forEach(nums, function(o, i){ o.className = st.Index == i ? "on" : ""; })

	}

	st.Run();