// JavaScript Document
var $ = 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 = $(container), oSlider = $(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 = $("idNum").getElementsByTagName("li");
  
  var tv = new TransformView("idTransformView", "idSlider", 190, 3, {
	  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();
	  }
  })
}