/*
间歇式无缝滚动
http://code.ciaoca.cn/
日期：2011-11-16

direction 参数说明
-----
left:自左向右
right:自右向左
top:自上向下
bottom:自下向上

settings 参数说明
-----
step:滚动步长
speed:滚动速度
time:自动滚动间隔时间
auto:是否自动滚动
plus:是否使用plus按钮
minus:是否使用minus按钮
------------------------------ */
(function($){
	$.fn.scrollshow=function(direction,settings){
		if(this.length<1){return;};

		// 默认值
		settings=$.extend({
			step:1,//滚动图片数
			speed:500,//滚动速度
			time:3000,//间隔时间
			auto:true,
			plus:true,
			minus:true
		},settings);

		var scroll_obj=this;
		var scroll_box=scroll_obj.find(".box");
		var scroll_list=scroll_box.find(".list");
		var scroll_array=scroll_list.find("li");
		var scroll_num=scroll_array.length;
	
		if(scroll_num<=1){return;};
	
		/*
		item_width	内部元素的宽度
		item_height	内部元素的高度
		*/
		var item_width,item_height;
		item_width=scroll_array.outerwidth();
		item_height=scroll_array.outerheight();
	
	
		var srcoll_html,scroll_run,plus_val,minus_val,scroll_val;
		if(direction=="left"||direction=="right"){
			if(item_width*scroll_num<=scroll_box.outerwidth()){return;};
			plus_val="left";
			minus_val="right";
			scroll_val=item_width;
		}else{
			if(item_height*scroll_num<=scroll_box.outerheight()){return;};
			plus_val="top";
			minus_val="bottom";
			scroll_val=item_height;
		};
	
		// 添加左右操作按钮
		srcoll_html="";
		if(scroll_obj.find(".plus").length<=0&&settings.plus){srcoll_html+="<a class='plus'></a>";};
		if(scroll_obj.find(".minus").length<=0&&settings.minus){srcoll_html+="<a class='minus'></a>";};
		scroll_obj.append(srcoll_html);
		var scroll_plus=scroll_obj.find(".plus");
		var scroll_minus=scroll_obj.find(".minus");
	
		// 添加后补元素
		scroll_list.append(scroll_list.html());

		// 自动滚动函数
		var scrollauto=function(){
			if(settings.auto){
				scroll_run=setinterval(function(){
					scrollstart(direction);
				},settings.time);
			}else{
				return;
			};
		};

		// 开始滚动函数
		var scrollstart=function(d){

			controlremove();
			scroll_list.stop(true);

			/*
			scroll_max	滚动的最大限度
			scroll_px	滚动的距离
			*/
			var scroll_max,scroll_px;
			switch(d){
			case "left":
			case "top":
				if(parseint(scroll_list.css(plus_val))==0){
					scroll_list.css(plus_val,-(scroll_num*scroll_val));
				};
				scroll_max=0;
				scroll_px=parseint(scroll_list.css(plus_val))+(scroll_val*settings.step);
				if(scroll_px>scroll_max){scroll_px=scroll_max};
				if(d=="left"){
					scroll_list.animate({left:scroll_px},settings.speed,function(){
						if(parseint(scroll_list.css(plus_val))>=0){
							scroll_list.css(plus_val,-(scroll_num*scroll_val));
						};
						controladd();
					});
				}else{
					scroll_list.animate({top:scroll_px},settings.speed,function(){
						if(parseint(scroll_list.css(plus_val))>=0){
							scroll_list.css(plus_val,-(scroll_num*scroll_val));
						};
						controladd();
					});
				};
				break;
			case "right":
			case "bottom":
				scroll_max=-(scroll_num*scroll_val);
				scroll_px=parseint(scroll_list.css(plus_val))-(scroll_val*settings.step);
				if(scroll_px<scroll_max){scroll_px=scroll_max};
				if(d=="right"){
					scroll_list.animate({left:scroll_px},settings.speed,function(){
						if(parseint(scroll_list.css(plus_val))<=scroll_max){
							scroll_list.css(plus_val,0);
						};
						controladd();
					});
				}else{
					scroll_list.animate({top:scroll_px},settings.speed,function(){
						if(parseint(scroll_list.css(plus_val))<=scroll_max){
							scroll_list.css(plus_val,0);
						};
						controladd();
					});
				};
				break;
			};
			
		};

		// 添加控制单击事件函数
		var controladd=function(){
			if(settings.plus){
				scroll_plus.bind("click",function(){
					if(typeof(scroll_run)!="undefined"){clearinterval(scroll_run);};
					scrollstart(plus_val);
					scrollauto();
				});
			};
			if(settings.minus){
				scroll_minus.bind("click",function(){
					if(typeof(scroll_run)!="undefined"){clearinterval(scroll_run);};
					scrollstart(minus_val);
					scrollauto();
				});
			};
		};

		// 解除控制事件函数

		var controlremove=function(){
			if(settings.plus){scroll_plus.unbind("click");};
			if(settings.minus){scroll_minus.unbind("click");};
		};
	
		if(settings.auto){
			// 开始自动滚动
			scrollauto();
		
			// 添加鼠标事件(移入暂停滚动,移出继续滚动)
			scroll_box.hover(function(){
				if(typeof(scroll_run)!="undefined"){clearinterval(scroll_run);};
			},function(){
				scrollauto();
			});
		};

		controladd()
	};
})(jquery);