/**
* @classDescription 模?Marquee，??????容
* @author Aken Li(www.kxbd.com)
* @DOM
*      <div id="marquee">
*          <ul>
*               <li></li>
*               <li></li>
*          </ul>
*      </div>
* @CSS
*      #marquee {width:200px;height:50px;overflow:hidden;}
* @Usage
*      $('#marquee').kxbdMarquee(options);
* @options
*    isEqual:true,//所有??的元素??是否相等,true,false
*      loop: 0,//循???次?，0??限
*    direction: 'left',//??方向，'left','right','up','down'
*    scrollAmount:1,//步?
*    scrollDelay:20//??
*/
(function($){

    $.fn.kxbdMarquee = function(options){
        var opts = $.extend({},$.fn.kxbdMarquee.defaults, options);
        
        return this.each(function(){
            var $marquee = $(this);//??元素容器
            var _scrollObj = $marquee.get(0);//??元素容器DOM
            var scrollW = $marquee.width();//??元素容器的?度
            var scrollH = $marquee.height();//??元素容器的高度
            var $element = $marquee.children(); //??元素
            var $kids = $element.children();//??子元素
            var scrollSize=0;//??元素尺寸
            var _type = (opts.direction == 'left' || opts.direction == 'right') ? 1:0;//???型，1左右，0上下
            
            //防止??子元素比??元素?而取不到????子元素?度
            $element.css(_type?'width':'height',10000);
            //?取??元素的尺寸
            if (opts.isEqual) {
                scrollSize = $kids[_type?'outerWidth':'outerHeight']() * $kids.length;
            }else{
                $kids.each(function(){
                    scrollSize += $(this)[_type?'outerWidth':'outerHeight']();
                });
            }
            //??元素?尺寸小于容器尺寸，不??
            if (scrollSize<(_type?scrollW:scrollH)) return;
            //克隆??子元素?其插入到??元素后，并?定??元素?度
            $element.append($kids.clone()).css(_type?'width':'height',scrollSize*2);
            
            var numMoved = 0;
            function scrollFunc(){
                var _dir = (opts.direction == 'left' || opts.direction == 'right') ? 'scrollLeft':'scrollTop';
                if (opts.loop > 0) {
                    numMoved+=opts.scrollAmount;
                    if(numMoved>scrollSize*opts.loop){
                        _scrollObj[_dir] = 0;
                        return clearInterval(moveId);
                    }
                }
                if(opts.direction == 'left' || opts.direction == 'up'){
                    _scrollObj[_dir] +=opts.scrollAmount;
                    if(_scrollObj[_dir]>=scrollSize){
                        _scrollObj[_dir] = 0;
                    }
                }else{
                    _scrollObj[_dir] -=opts.scrollAmount;
                    if(_scrollObj[_dir]<=0){
                        _scrollObj[_dir] = scrollSize;
                    }
                }
            }
            //???始
            var moveId = setInterval(scrollFunc, opts.scrollDelay);
            //鼠?划?停止??
            $marquee.hover(
                function(){
                    clearInterval(moveId);
                },
                function(){
                    clearInterval(moveId);
                    moveId = setInterval(scrollFunc, opts.scrollDelay);
                }
            );
            
        });
    };
    $.fn.kxbdMarquee.defaults = {
        isEqual:true,//所有??的元素??是否相等,true,false
        loop: 0,//循???次?，0??限
        direction: 'left',//??方向，'left','right','up','down'
        scrollAmount:1,//步?
        scrollDelay:40//??

    };
    $.fn.kxbdMarquee.setDefaults = function(settings) {
        $.extend( $.fn.kxbdMarquee.defaults, settings );
    };
})(jQuery);