// JavaScript Document
var ljf = function (id) {
        return "string" == typeof id ? document.getElementById(id) : id;
};

var Class = {
  create: function() {
        return function() {
          this.initialize.apply(this, arguments);
        }
  }
}

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

var TransformView = Class.create();
TransformView.prototype = {
  //容器对象,滑动对象,切换参数,切换数量
  initialize: function(container, slider, parameter, count, options) {
        if(parameter <= 0 || count <= 0) return;
        var oContainer = ljf(container), oSlider = ljf(slider), oThis = this;

        this.Index = 0;//当前索引
        
        this._timer = null;//定时器
        this._slider = oSlider;//滑动对象
        this._parameter = parameter;//切换参数
        this._count = count || 0;//切换数量
        this._target = 0;//目标参数
        
        this.SetOptions(options);
        
        this.Up = !!this.options.Up;
        this.Step = Math.abs(this.options.Step);
        this.Time = Math.abs(this.options.Time);
        this.Auto = !!this.options.Auto;
        this.Pause = Math.abs(this.options.Pause);
        this.onStart = this.options.onStart;
        this.onFinish = this.options.onFinish;
        
        oContainer.style.overflow = "hidden";
        oContainer.style.position = "relative";
        
        oSlider.style.position = "absolute";
        oSlider.style.top = oSlider.style.left = 0;
  },
  //设置默认属性
  SetOptions: function(options) {
        this.options = {//默认值
                Up:                        true,//是否向上(否则向左)
                Step:                5,//滑动变化率
                Time:                10,//滑动延时
                Auto:                true,//是否自动转换
                Pause:                2000,//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
        };
        Object.extend(this.options, options || {});
  },
  //开始切换设置
  Start: function() {
        if(this.Index < 0){
                this.Index = this._count - 1;
        } else if (this.Index >= this._count){ this.Index = 0; }
        
        this._target = -1 * this._parameter * this.Index;
        this.onStart();
        this.Move();
  },
  //移动
  Move: function() {
        clearTimeout(this._timer);
        var oThis = this, style = this.Up ? "top" : "left", iNow = parseInt(this._slider.style[style]) || 0, iStep = this.GetStep(this._target, iNow);
        
        if (iStep != 0) {
                this._slider.style[style] = (iNow + iStep) + "px";
                this._timer = setTimeout(function(){ oThis.Move(); }, this.Time);
        } else {
                this._slider.style[style] = this._target + "px";
                this.onFinish();
                if (this.Auto) { this._timer = setTimeout(function(){ oThis.Index++; oThis.Start(); }, this.Pause); }
        }
  },
  //获取步长
  GetStep: function(iTarget, iNow) {
        var iStep = (iTarget - iNow) / this.Step;
        if (iStep == 0) return 0;
        if (Math.abs(iStep) < 1) return (iStep > 0 ? 1 : -1);
        return iStep;
  },
  //停止
  Stop: function(iTarget, iNow) {
        clearTimeout(this._timer);
        this._slider.style[this.Up ? "top" : "left"] = this._target + "px";
  }
};

window.onload=function(){
        function Each(list, fun){
                for (var i = 0, len = list.length; i < len; i++) { fun(list[i], i); }
        };
        
        var objs = ljf("idNum").getElementsByTagName("li");
        
        var tv = new TransformView("idTransformView", "idSlider", 210, 5, {
                onStart : function(){ Each(objs, function(o, i){ o.className = tv.Index == i ? "on" : ""; }) }//按钮样式
        });
        
        tv.Start();
        
        Each(objs, function(o, i){
                o.onmouseover = function(){
                        o.className = "on";
                        tv.Auto = false;
                        tv.Index = i;
                        tv.Start();
                }
                o.onmouseout = function(){
                        o.className = "";
                        tv.Auto = true;
                        tv.Start();
                }
        })
}