(function($){

$.zui = $.zui || {}
$.zui.emptyfn = function(){};
$.zui.aswidget = [];
/*
 * core代码，定义增加一个插件的骨架
 */
$.zui.addwidget = function(sname,osefdef){
	//设置规范中的常量sflagname、seventname、soptsname
	$.zui.aswidget.push(sname);
	var w = $.zui[sname] = $.zui[sname] || {};
	var sprefix = "zui" + sname
	w.sflagname = sprefix;
	w.seventname = sprefix + "event";
	w.soptsname = sprefix + "opts";
	w.__creator = $.zui.emptyfn;
	w.__destroyer = $.zui.emptyfn;
	$.extend(w,osefdef);
	w.fn = function(ele,opts){
		var jqele = $(ele);
		jqele.data(w.soptsname,$.extend({},w.defaults,opts));
		//如果该元素已经执行过了该插件，直接返回，仅相当于修改了配置参数
		if(jqele.data(w.sflagname)){
			return;
		}
		jqele.data(w.sflagname,true);
		w.__creator(ele);
		jqele.on(jqele.data(w.seventname));
	};
	w.unfn = function(ele){
		w.__destroyer(ele);
		var jqele = $(ele);//移除监听事件
		if(jqele.data(w.sflagname)){
			jqele.off(jqele.data(w.seventname));
			jqele.data(w.sflagname,false);
		}
	}
	
}
/*
 * draggable
 * 参数：obj{
 * boffsetparentboundary:是否以定位父亲元素为边界,
 * oboundary:指定元素left和top的边界值，形如{iminleft:...,imaxleft:...,imintop:...,imaxtop:...},与上一个参数互斥
 * fncomputeposition:扩展函数，返回形如{left:...,top:...}的对象
 * }
 * 支持的自定义事件:
 * "draggable.start":drag起始，就是鼠标down后触发
 * "draggable.move":drag过程中多次触发
 * "draggable.stop":drag结束触发，就是鼠标up后触发
 */
//注册draggable组件
$.zui.addwidget("draggable",{
	defaults:{
		boffsetparentboundary:false,//是否以定位父亲元素为边界
		oboundary:null,//边界
		fncomputeposition:null//计算位置的函数
	},
	__creator:function(ele){
		var jqele = $(ele);
		jqele.data($.zui.draggable.seventname,{
		mousedown:function(ev){
		var jqthis = $(this);
		var opts = jqthis.data($.zui.draggable.soptsname);
		
		jqthis.trigger("draggable.start");
		var ioffsetx = ev.pagex - this.offsetleft;
		var ioffsety = ev.pagey - this.offsettop;
		
		function fnmousemove (ev) {
			var opos = {};
			if(opts.fncomputeposition){
				opos = opts.fncomputeposition(ev,ioffsetx,ioffsety);
			}else{
				opos.ileft = ev.pagex - ioffsetx;
				opos.itop = ev.pagey - ioffsety;
			}
			
			var oboundary = opts.oboundary;
			if(opts.boffsetparentboundary){//如果以offsetparent作为边界
				var eparent = jqthis.offsetparent()[0];
				oboundary = {};
				oboundary.iminleft = 0;
				oboundary.imintop = 0;
				oboundary.imaxleft = eparent.clientwidth - jqthis.outerwidth();
				oboundary.imaxtop = eparent.clientheight - jqthis.outerheight();
			}
		
			if(oboundary){//如果存在oboundary，将oboundary作为边界
				opos.ileft = opos.ileft < oboundary.iminleft ? oboundary.iminleft : opos.ileft;
				opos.ileft = opos.ileft > oboundary.imaxleft ? oboundary.imaxleft : opos.ileft;
				opos.itop = opos.itop < oboundary.imintop ? oboundary.imintop : opos.itop;
				opos.itop = opos.itop > oboundary.imaxtop ? oboundary.imaxtop : opos.itop;
			}
			
			jqthis.css({left:opos.ileft,top:opos.itop});
			ev.preventdefault();
			jqthis.trigger("draggable.move");
		}
		
		var oevent = {
			mousemove:fnmousemove,
			mouseup:function(){
				$(document).off(oevent);
				jqthis.trigger("draggable.stop");
			}
		};
		
		$(document).on(oevent);
	}});
	}
});
/*
 * panel
 * 参数：obj{
 * 	iwheelstep:鼠标滑轮滚动时步进长度
 *	sboxclassname:滚动框的样式
 * 	sbarclassname:滚动条的样式
 * }
 */
$.zui.addwidget("panel",{
	defaults : {
			iwheelstep:16,
			sboxclassname:"zuipanelscrollbox",
			sbarclassname:"zuipanelscrollbar"
	},
	__creator:function(ele){
		var jqthis = $(ele);
		//如果是static定位，加上relative定位
		if(jqthis.css("position") === "static"){
			jqthis.css("position","relative");
		}
		jqthis.css("overflow","hidden");
		
		//必须有一个唯一的直接子元素,给直接子元素加上绝对定位
		var jqchild = jqthis.children(":first");
		if(jqchild.length){
			jqchild.css({top:0,position:"absolute"});
		}else{
			return;
		}
		
		var opts = jqthis.data($.zui.panel.soptsname);
		//创建滚动框
		var jqscrollbox = $("<div style='position:absolute;display:none;line-height:0;'></div>");
		jqscrollbox.addclass(opts.sboxclassname);
		//创建滚动条
		var jqscrollbar= $("<div style='position:absolute;display:none;line-height:0;'></div>");
		jqscrollbar.addclass(opts.sbarclassname);
		jqscrollbox.appendto(jqthis);
		jqscrollbar.appendto(jqthis);
		
		opts.itop = parseint(jqscrollbox.css("top"));
		opts.iwidth = jqscrollbar.width();
		opts.iright = parseint(jqscrollbox.css("right"));
		

		//添加拖拽触发自定义函数
		jqscrollbar.on("draggable.move",function(){
			var opts = jqthis.data($.zui.panel.soptsname);
			fnscrollcontent(jqscrollbox,jqscrollbar,jqthis,jqchild,opts.itop,0);
		});
		
	  //事件对象
		var oevent ={
			mouseenter:function(){
				fnfreshscroll();
				jqscrollbox.css("display","block");
				jqscrollbar.css("display","block");
			},
			mouseleave:function(){
				jqscrollbox.css("display","none");
				jqscrollbar.css("display","none");
			}
		};
		
		var smousewheel = "mousewheel";
		if(!("onmousewheel" in document)){
			smousewheel = "dommousescroll";
		}
		oevent[smousewheel] = function(ev){
			var opts = jqthis.data($.zui.panel.soptsname);
			var iwheeldelta = 1;
			ev.preventdefault();//阻止默认事件
			ev = ev.originalevent;//获取原生的event
			if(ev.wheeldelta){
					iwheeldelta = ev.wheeldelta/120;
			}else{
					iwheeldelta = -ev.detail/3;
			}
			var imintop = jqthis.innerheight() - jqchild.outerheight();
			//外面比里面高，不需要响应滚动
			if(imintop>0){
				jqchild.css("top",0);
				return;
			}
			var itop = parseint(jqchild.css("top"));
			var itop = itop + opts.iwheelstep*iwheeldelta;
			itop = itop > 0 ? 0 : itop;
			itop = itop < imintop ? imintop : itop;
			jqchild.css("top",itop);
			fnscrollcontent(jqthis,jqchild,jqscrollbox,jqscrollbar,0,opts.itop);
		}
		//记录添加事件
		jqthis.data($.zui.panel.seventname,oevent);
		//跟随滚动函数
		function fnscrollcontent(jqwrapper,jqcontent,jqfollowwrapper,jqflollowcontent,ioffset1,ioffset2){
			var opts = jqthis.data($.zui.panel.soptsname);
			var rate = (parseint(jqcontent.css("top"))-ioffset1)/(jqcontent.outerheight()-jqwrapper.innerheight())//卷起的比率
			var itop = (jqflollowcontent.outerheight()-jqfollowwrapper.innerheight())*rate + ioffset2;
			jqflollowcontent.css("top",itop);
		}
	
		//刷新滚动条
		function fnfreshscroll(){

			var opts = jqthis.data($.zui.panel.soptsname);
			var iscrollboxheight = jqthis.innerheight()-2*opts.itop;
			var irate = jqthis.innerheight()/jqchild.outerheight();
			var iscrollbarheight = iscrollbarheight = math.round(irate*iscrollboxheight);
			//如果比率大于等于1，不需要滚动条,自然也不需要添加拖拽事件
			if(irate >= 1){
				jqscrollbox.css("height",0);
				jqscrollbar.css("height",0);
				return;
			}
			jqscrollbox.css("height",iscrollboxheight);
			jqscrollbar.css("height",iscrollbarheight);
			//计算拖拽边界，添加拖拽事件
			var oboundary = {imintop:opts.itop};
			oboundary.imaxtop = iscrollboxheight - math.round(irate*iscrollboxheight)+opts.itop;
			oboundary.iminleft = jqthis.innerwidth() - opts.iwidth - opts.iright;
			oboundary.imaxleft = oboundary.iminleft;
			fnscrollcontent(jqthis,jqchild,jqscrollbox,jqscrollbar,0,opts.itop);
			jqscrollbar.draggable({oboundary:oboundary});
		}
	},
		__destroyer:function(ele){
			var jqele = $(ele);
			if(jqele.data($.zui.panel.sflagname)){
				var opts = jqele.data($.zui.panel.soptsname);
				jqele.children("."+opts.sboxclassname).remove();
				jqele.children("."+opts.sbarclassname).remove();
			}
	}
});

$.each($.zui.aswidget,function(i,widget){
	unwidget = "un"+widget;
	var w = {};
	w[widget] = function(args){
			this.each(function(){
			$.zui[widget].fn(this,args);
		});
		return this;
	};
	w[unwidget] = function(){
			this.each(function(){
			$.zui[widget].unfn(this);
		});
		return this;
	}
	$.fn.extend(w);
});
})(jquery);