/*
#首页JS名字空间
2010/6/4
*/
var CIndex = {};

CIndex.initSlide = function( bigPicsID, smallPicsID, descID ){
	CSlide.init( bigPicsID, smallPicsID, descID );
};

/*幻灯片图片展示*/
var CSlide = {};

CSlide.bigPicHeight = 300;

CSlide.bigPicsID = "";

CSlide.smallPicsID = "";

CSlide.descID = "";

CSlide.bigPics = null;

CSlide.smallPics = null;

CSlide.desc = null;

CSlide.bigPicsContainer = null;

CSlide.currentIndex = 0;

CSlide.currentTop = 0; //当前picsContainer的Top

CSlide.interval = 3000; //每隔3秒钟，焦点图自动切换一次

CSlide.completeTime = 1000; //多久完成2幅大图的切换

CSlide.times = 50; //多少次移动完成图片的切换

CSlide.scrollTimeHandle = null;

CSlide.scrollStoped = false; //用户触动的切换是否停止

CSlide.timedChangeHandle = null; //定时切换焦点图的定时器句柄

CSlide.restDist = 0;

CSlide.num = 0; //焦点图的个数

CSlide.init = function( bigPicsID, smallPicsID, descID ){
	var _t = CSlide;
	_t.bigPics = $( "#" + bigPicsID + " > ul > li" );
	_t.smallPics = $( "#" + smallPicsID + " > ul > li" );
	_t.desc = $( "#" + descID + " > ul > li" );
	_t.bigPicsID = bigPicsID;
	_t.smallPicsID = smallPicsID;
	_t.descID = descID;
	_t.bigPicsContainer = $( "#" + bigPicsID );
	_t.num = _t.smallPics.length;
	//为小图绑定onmouse事件
	for( var i = 0; i < _t.smallPics.length; i++ ){
		$( _t.smallPics[i] ).attr( "for", i );
		$( _t.bigPics[i] ).attr( "for", i );
		$( _t.desc[i] ).attr( "for", i );
	}
	_t.smallPics.mouseover( function(){
		clearTimeout( _t.timedChangeHandle );
		var index = parseInt( $(this).attr( "for" ) );
		_t.scroll( _t.currentIndex, index );
	} );
	_t.smallPics.mouseout( function(){
		var index = parseInt( $(this).attr( "for" ) );
		_t.timedChange();
	} );
	_t.timedChange();
};

//大图滚动
CSlide.scroll = function( fromIndex, toIndex ){
	var _t = CSlide;
	_t.smallPics[fromIndex].className = "";
	_t.smallPics[toIndex].className = "current";
	_t.desc[fromIndex].className = "";
	_t.desc[toIndex].className = "current";
	var offset = toIndex - fromIndex;
	if( offset == 0 )
		return false;
	var targetTop = -1 * _t.bigPicHeight * toIndex; //目标top
	var currentTop = parseInt( _t.bigPicsContainer.css( "top" ) );
	var distance = targetTop - currentTop;
	//自动移动的次数
	if( Math.abs( offset ) > 2 ){
		_t.times = 120; 
	}
	var lastSpeed = distance % _t.times; //最后一次移动的像素数
	var speed = parseInt( distance/_t.times ); //平均每次移动的像素数
	clearInterval( _t.scrollTimeHandle ); //停止手动触发的自动滚动
	//clearTimeout( _t.timedChangeHandle );
	//alert( speed );
	_t.scrollTimeHandle = setInterval( function(){ _t.move( speed ); }, 10 ); //每20ms移动一次
	setTimeout( function(){ _t.move( lastSpeed ); }, 10 );
	_t.currentIndex = toIndex;
};

//将bigPicsContainer的top定时移动某个距离
CSlide.move = function( dist ){
	var _t = CSlide;
	var currentTop = parseInt( _t.bigPicsContainer.css( "top" ) );
	var newTop = ( currentTop + dist ) + "px";
	_t.bigPicsContainer.css( "top", newTop );
	_t.times--;
	if( _t.times == -1 ){
		clearInterval( _t.scrollTimeHandle );
		_t.times = 50;
	}
};

//定时切换焦点图
CSlide.timedChange = function(){
	var _t = CSlide;
	_t.timedChangeHandle = setInterval( function(){ var nextIndex = _t.currentIndex+1; if( nextIndex == _t.smallPics.length ) nextIndex = 0; _t.scroll( _t.currentIndex, nextIndex ); }, 5000 );
};