/*
 *滑动展示箱子
 */
function ScrollBox(){
//实例名称
this.instName;

//滚动区ID
this.scrollZoneId='';

//滑动区ID
this.sliderZoneId='';

//滑动区域横坐标(相对于滚动区)
this.x_coordinate=0;

//动作前滑动区横坐标
this.X=0;

//单元宽度
this.unitWidth=0;

//单元个数
this.unitSize=0;

//滚动区显示单元个数
this.showUnitSize=0;

//计时器
this.timer=null;

//计时间隔
this.interval=24;

//移动幅度.
this.moveRange=2;

//目前在显示的首单元索引号
this.firstShowUnitIndex=1;

//水平滑动方向 -1:左,1右
this.slideDirection=-1;
/**************************************************************/
/**************************************************************/
/**************************************************************/
/*
 * 初始化
 */
this.init=function(i_name,sc_id,sl_id,u_width,s_size,u_size){
	
	this.instName=i_name;
	this.scrollZoneId=sc_id;
	this.sliderZoneId=sl_id;
	this.unitWidth=u_width;
	this.showUnitSize=s_size;
	this.unitSize=u_size;
		
}

/*
 * 水平移动一段距离
 */
this.move=function(range){
    var s_zone =document.getElementById(this.sliderZoneId);	
	this.x_coordinate=this.x_coordinate+range;
	s_zone.style.left=this.x_coordinate+'px';	
}

/*
 * 向左水平移动一定距离
 */
this.moveLeft=function(moveLength){
	this.move(-moveLength);
}
/*
 * 向右水平移动一定距离
 */
this.moveRight=function(moveLength){
   this.move(moveLength);	
}
/*
 * 关闭计时器
 */
this.stopTimer=function(){
	window.clearTimeout(this.timer);
}

/*
 * 向左滑动展示下一个单元
 */
this.nextUnitLeft=function(){
	
   if(this.X==((this.showUnitSize-this.unitSize)*this.unitWidth)){
	  return ;
   }
   if(this.x_coordinate==this.X-this.unitWidth){
	  this.X=this.X-this.unitWidth;
	  this.stopTimer();
	  return;
   }
   this.moveLeft(this.moveRange);
   this.timer=window.setTimeout(this.instName+'.nextUnitLeft();',1);
}

/*
 * 向右滑动展示下一个单元
 */
this.nextUnitRight=function(){
	
	if(this.X==0){
	  return ;
	}
	
    if(this.x_coordinate==this.X+this.unitWidth){	
	  this.X=this.X+this.unitWidth;
	  this.stopTimer();
	  return;
	}
	this.moveRight(this.moveRange);
	this.timer=window.setTimeout(this.instName+'.nextUnitRight();',1);

}

/**
  * 向左滑动
  */
this.slideLeft=function(){
	this.moveLeft(this.moveRange);
	this.timer=window.setTimeout(this.instName+'.slideLeft();',this.interval);
}

/**
  * 向右滑动
  */
this.slideRight=function(){
	this.moveRight(this.moveRange);
	this.timer=window.setTimeout(this.instName+'.slideRight();',this.interval);
}

/**
  * 停止滑动
  */
this.stopSlide=function(){
	
	this.X=parseInt(this.x_coordinate/this.unitWidth)*this.unitWidth;
	//this.X=(parseInt(this.x_coordinate/this.unitWidth)+1)*this.unitWidth;
	//this.X=-540;
	this.stopTimer();
}

/*
 *自动滑动
 */
this.autoSlide=function(){
	
	if( (this.slideDirection==1 && this.x_coordinate==0 )|| 
		(this.slideDirection==-1 && this.x_coordinate==(this.showUnitSize-this.unitSize)*this.unitWidth) ){
	    this.slideDirection=this.slideDirection*-1;
	}	
	this.move(this.slideDirection*this.moveRange);	
	this.timer=window.setTimeout(this.instName+'.autoSlide();',this.interval);
}


}