/**  
　　　* @author xf.radish  
 * jQuery插件 常用效果的实现  
 */  
(function (jQuery) {  
    jQuery.fn.extend({  
        /**  
         *@description 无缝滚动 支持匀速上下左右和垂直翻滚上下  
         *@param {  
          *      direction:string,//滚动方向 值域：top|left|bottom|right|up|down  
         *      speed:string//滚动速度（垂直翻滚时为停留时间）  
         * } o  
         *@example  
         *HTML结构  
         *<div id="mar">  
         *    <div>  
         *        <li>内容1</li>  
         *        <li>内容2</li>  
         *        <li>内容3</li>  
         *    </div>  
         *</div>  
         *mar样式应该包含height,width,background等 注意不要覆盖了插件附加上去的样式  
         *调用：  
         *jQuery("#mar").marquee({  
         *    direction:"top",  
         *    speed:30  
         *})  
         *  
         */  
        marquee:function (o) {  
            var it = this,  
                    d = o.direction || 'left', //滚动方向 默认向左  
                    s = o.speed || 30, //速度 默认30毫秒  
                    mar = jQuery(it),  
                    mp1 = jQuery(it).children(0).attr({id:"mp1"}),  
                    marqueeFunc = getMarquee(d),  
                    marRun = marqueeFunc ? setInterval(marqueeFunc, s) : function () {  
                        return false;  
                    };//开始滚动  
            //鼠标悬停事件  
            jQuery(it).hover(function () {  
                clearInterval(marRun);  
            }, function () {  
                marRun = setInterval(marqueeFunc, s);  
            })  
            /*生成滚动函数  
             *1.判断方向 *2.装载CSS *3.判断需不需要滚动 *4.构造函数  
             */  
            function getMarquee(d) {  
                var marqueeFunc;  
                switch (d) {  
                    //水平向左  
                    case "left":  
                        mar.addClass("plus-mar-left");  
                        var liHeight = mar[0].offsetHeight;  
                        mar.css({"line-height":liHeight + "px"});  
                        if (mp1[0].offsetWidth < mar[0].offsetWidth) return false;  
                        mp1.clone().attr({id:"mp2"}).appendTo(mar);  
                        marqueeFunc = function () {  
                            if (mar[0].scrollLeft >= mp1[0].scrollWidth) {  
                                mar[0].scrollLeft = 0;  
                            } else {  
                                mar[0].scrollLeft++;  
                            }  
                        }  
                        break;  
                    //水平向上  
                    case "top":  
                        mar.addClass("plus-mar-top");  
                        if (mp1.outerHeight() <= mar.outerHeight()) return false;  
                        var mp2 = mp1.clone().attr({id:"mp2"}).appendTo(mar);  
                        marqueeFunc = function () {  
                            var scrollTop = mar[0].scrollTop;  
                            if (mp1[0].offsetHeight > scrollTop) {  
                                mar[0].scrollTop = scrollTop + 1;  
                            } else {  
                                mar[0].scrollTop = 0;  
                            }  
                        }  
                        break;  
                    //水平向右  
                    case "right":  
                        mar.addClass("plus-mar-left");  
                        var liHeight = mar[0].offsetHeight;  
                        mar.css({"line-height":liHeight + "px"});  
                        if (mp1[0].offsetWidth <= mar[0].offsetWidth) return false;  
                        var mp2 = mp1.clone().attr({id:"mp2"}).appendTo(mar);  
                        marqueeFunc = function () {  
                            if (mar[0].scrollLeft <= 0) {  
                                mar[0].scrollLeft += mp2[0].offsetWidth;  
                            } else {  
                                mar[0].scrollLeft--;  
                            }  
                        }  
                        break;  
                    //水平向下  
                    case "bottom":  
                        mar.addClass("plus-mar-bottom");  
                        if (mp1[0].offsetHeight <= mar[0].offsetHeight) return false;  
                        var mp2 = mp1.clone().attr({id:"mp2"}).appendTo(mar);  
                        mar[0].scrollTop = mar[0].scrollHeight;  
                        marqueeFunc = function () {  
                            if (mp1[0].offsetTop >= mar[0].scrollTop) {  
                                mar[0].scrollTop += mp1[0].offsetHeight;  
                            } else {  
                                mar[0].scrollTop--;  

                            }  
                        }  
                        break;  
                    //垂直翻滚 向上  
                    case "up":  
                        mar.addClass("plus-mar-up");  
                        var liHeight = mar[0].offsetHeight;  
                        mp1.css({"line-height":liHeight + "px"});  
                        marqueeFunc = function () {  
                            var currLi = it.eq(0).find("ul:first");  
                            currLi.animate({  
                                marginTop:-liHeight  
                            }, 500, function () {  
                                currLi.find("li:first").appendTo(currLi);  
                                currLi.css({marginTop:0});  
                            })  
                        }  
                        break;  
                    //垂直翻滚 向下  
                    case "down":  
                        mar.addClass("plus-mar-down");  
                        var liHeight = mar[0].offsetHeight,  
                                liLength = mp1.children().length,  
                                topInit = -(liLength - 1) * liHeight + "px";  
                        mp1.css({"top":topInit, "line-height":liHeight + "px"});  
                        marqueeFunc = function () {  
                            var currLi = it.eq(0).find("ul:last");  
                            currLi.animate({  
                                marginTop:liHeight  
                            }, 500, function () {  
                                currLi.find("li:last").prependTo(currLi);  
                                currLi.css({marginTop:0});  
                            })  
                        }  
                        break;  
                    default:  
                    {  
                        marqueeFunc = null;  
                        alert("滚动插件：传入的参数{direction}有误！");  
                    }  
                }  
                return marqueeFunc;  
            }  
        }  
    })  
})(jQuery);