/**
 * 图片切换插件
 * Dependence jquery-1.7.2.min.js
 **/
(function ($) {
  //调用方式 $('#silder').imgSilder({s_width:564, s_height:293, is_showTit:true, s_times:3000,css_link:'css/style.css'});  容器必须加入 id silder_list or class silder_list
  /*参考结构
    <div class="silder" id="silder">
        <ul class="silder_list" id="silder_list">
            <li>
                <img src="css/img/1.jpg" border="0" alt="刘淇同志参观北京市志愿者之家">
            </li>
            <li>
                <img src="css/img/2.jpg" border="0" alt="刘淇同志与志愿者合影">
            </li>
            <li>
                <img src="css/img/3.jpg" border="0" alt="刘淇同志到北京大学人民医院调研">
            </li>
            <li>
                <img src="css/img/4.jpg" border="0" alt="2013中国志愿服务国际交流大会在京举行">
            </li>                   
        </ul>
    </div>
  */
  $.fn.silderDefaults = { //默认参数
    s_width:500, //容器宽度
    s_height:500, //容器高度
    is_showTit:true, // 是否显示图片标题 false :不显示，true :显示
    s_times:3000, //设置滚动时间
    css_link:'css/style.css'
  };
  $.extendSilder = function (obj,opt) { //obj 元素对象，opt 参数对象
    var g = {  //公共方法， 外部可调用
      //初始化
        init: function () {
            var wh ={width:opt.s_width,height:opt.s_height};
            var pagesize=0; //页码
            var silderList = $('#silder_list',g.obj);
            var silderList_li = $('#silder_list li',g.obj);
            g.LoadCSS(opt.css_link); //样式文件导入
            g.obj.css(wh); silderList.css(wh); silderList_li.find('img').css(wh); //设置宽高属性
            var currHtml = ""; //加入播放页码 及文字描述
            if(opt.is_showTit){ //判断是否显示标题
                currHtml += "<div class='silder_desc' id='silder_desc'></div>";
            }
            img_size = silderList_li.size() ;//图片个数
            currHtml += "<ul class='silder_page' id='silder_page'>";//分页码代码注入
            for(var i=0; i < img_size; i++){
                currHtml += "<li>"+ parseInt((1 + i),10) +"</li>";
            }
            currHtml +="</ul>";
            silderList_li.eq(0).show().siblings().hide(); //初始化隐藏其他图片
            g.obj.append(currHtml);//注入分页码
            var silderPage = $('#silder_page',g.obj);
            var silderPage_li =$('#silder_page li',g.obj);
            silderPage_li.eq(0).addClass('current');
            if(opt.is_showTit){ //初始化图片描述
                $('#silder_desc').text(silderList_li.eq(0).find('img').attr('alt'));
            }
            silderPage_li.on('click',function(){
                pagesize = $(this).index();
                silderList_li.eq(pagesize).fadeIn(1000).siblings().fadeOut(100);
                $(this).addClass('current').siblings().removeClass('current');
                if(opt.is_showTit){
                    $('#silder_desc').text(silderList_li.eq(pagesize).find('img').attr('alt'));
                }
            });
            var t;
            silderList.hover(function(){window.clearInterval(t); return;},function(){ t = window.setInterval(function(){
                if(pagesize < img_size && pagesize >= 0)
                {
                    silderList_li.eq(pagesize).fadeIn(1000).siblings().fadeOut(100);
                    silderPage_li.eq(pagesize).addClass('current').siblings().removeClass('current');
                    if(opt.is_showTit){
                        $('#silder_desc').text(silderList_li.eq(pagesize).find('img').attr('alt'));
                    }
                    pagesize++;
                    if(pagesize >= img_size){
                        pagesize = 0;
                    }
                }
            },opt.s_times);}).trigger("mouseout"); //悬浮时 停止自动动画,trigger 起默认触发作用
        },
          LoadCSS:function(url){ //新建css
            var s = document.createElement("LINK");
                s.rel = "stylesheet";
                s.type = "text/css";
                s.href = url;
                document.getElementsByTagName("HEAD")[0].appendChild(s);
          }
    };
    g.obj = $(obj);
    g.init();
    return g;
  }
  $.fn.imgSilder = function (options) {
    if (this.length == 0) return; //判断对象是否存在
    this.each(function () {
      if (this.usedSilder) return;
      var opt = $.extend({}, $.fn.silderDefaults, options); //合并已赋值参数
      this.usedSilder = $.extendSilder(this, opt);
    });
  }
})(jQuery);