/**
* @classDescription 模拟Marquee，无间断滚动内容
* @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
*  	$('#marquee').kxbdMarquee(options);
* @options
*		isEqual:true,//所有滚动的元素长宽是否相等,true,false
*  	loop: 0,//循环滚动次数，0时无限
*		direction: 'left',//滚动方向，'left','right','up','down'
*		scrollAmount:1,//步长
*		scrollDelay:20//时长
*/
(function ($) {

    $.fn.kxbdMarquee = function (options) {
        var opts = $.extend({}, $.fn.kxbdMarquee.defaults, options);

        return this.each(function () {
            var $marquee = $(this); //滚动元素容器
            var _scrollObj = $marquee.get(0); //滚动元素容器DOM
            var scrollW = $marquee.width(); //滚动元素容器的宽度
            var scrollH = $marquee.height(); //滚动元素容器的高度
            var $element = $marquee.children(); //滚动元素
            var $kids = $element.children(); //滚动子元素
            var scrollSize = 0; //滚动元素尺寸
            var _type = (opts.direction == 'left' || opts.direction == 'right') ? 1 : 0; //滚动类型，1左右，0上下

            //防止滚动子元素比滚动元素宽而取不到实际滚动子元素宽度
            $element.css(_type ? 'width' : 'height', 784);

            //获取滚动元素的尺寸
            if (false) {
                scrollSize = $kids[_type ? 'outerWidth' : 'outerHeight']() * $kids.length;
            } else {
                $kids.each(function () {
                    scrollSize += $(this)[_type ? 'outerWidth' : 'outerHeight']();
                });
            }

            //滚动元素总尺寸小于容器尺寸，不滚动
            if (scrollSize < (_type ? scrollW : scrollH)) return;
            //克隆滚动子元素将其插入到滚动元素后，并设定滚动元素宽度
            $element.append($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') {
                    var newPos = _scrollObj[_dir] + opts.scrollAmount;
                    if (newPos >= scrollSize) {
                        newPos -= scrollSize;
                    }
                    _scrollObj[_dir] = newPos;
                } else {
                    var newPos = _scrollObj[_dir] - opts.scrollAmount;
                    if (newPos <= 0) {
                        newPos += scrollSize;
                    }
                    _scrollObj[_dir] = newPos;
                }
            }
            //滚动开始
            var moveId = setInterval(scrollFunc, opts.scrollDelay);
            //鼠标划过停止滚动
            $marquee.hover(
				function () {
				    clearInterval(moveId);
				},
				function () {
				    clearInterval(moveId);
				    moveId = setInterval(scrollFunc, opts.scrollDelay);
				}
			);

        });
    };
    $.fn.kxbdMarquee.defaults = {
        isEqual: true, //所有滚动的元素长宽是否相等,true,false
        loop: 0, //循环滚动次数，0时无限
        direction: 'left', //滚动方向，'left','right','up','down'
        scrollAmount: 1, //步长
        scrollDelay: 20//时长

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