/**
 * 圖片切換插件
 * Dependence jquery-1.7.2.min.js
 **/
(function ($) {
  //調用方式 $('#silder').imgSilder({s_width:564, s_height:293, is_showTit:true, s_times:3000,css_link:'css/style.css'});  容器必須加入 id silder_list or class silder_list
  /*參考結構
    <div class="silder" id="silder">
        <ul class="silder_list" id="silder_list">
            <li>
                <img src="css/img/1.jpg" border="0" alt="劉淇同志參觀北京市志愿者之家">
            </li>
            <li>
                <img src="css/img/2.jpg" border="0" alt="劉淇同志與志愿者合影">
            </li>
            <li>
                <img src="css/img/3.jpg" border="0" alt="劉淇同志到北京大學人民醫院調研">
            </li>
            <li>
                <img src="css/img/4.jpg" border="0" alt="2013中國志愿服務國際交流大會在京舉行">
            </li>                    
        </ul>
    </div>
  */
  $.fn.silderDefaults = { //默認參數
    s_width:500, //容器寬度
    s_height:500, //容器高度
    is_showTit:true, // 是否顯示圖片標題 false :不顯示，true :顯示
    s_times:3000, //設置滾動時間
    css_link:'css/style.css'
  };
  $.extendSilder = function (obj,opt) { //obj 元素對象，opt 參數對象
    var g = {  //公共方法， 外部可調用
      //初始化
        init: function () {
            var wh ={width:opt.s_width,height:opt.s_height};
            var pagesize=0; //頁碼
            var silderList = $('#silder_list',g.obj);
            var silderList_li = $('#silder_list li',g.obj);
            g.LoadCSS(opt.css_link); //樣式文件導入
            g.obj.css(wh); silderList.css(wh); silderList_li.find('img').css(wh); //設置寬高屬性
            var currHtml = ""; //加入播放頁碼 及文字描述
            if(opt.is_showTit){ //判斷是否顯示標題
                currHtml += "<div class='silder_desc' id='silder_desc'></div>";
            }
            img_size = silderList_li.size() ;//圖片個數
            currHtml += "<ul class='silder_page' id='silder_page'>";//分頁碼代碼注入
            for(var i=0; i < img_size; i++){
                currHtml += "<li>"+ parseInt((1 + i),10) +"</li>";
            }
            currHtml +="</ul>";
            silderList_li.eq(0).show().siblings().hide(); //初始化隱藏其他圖片
            g.obj.append(currHtml);//注入分頁碼
            var silderPage = $('#silder_page',g.obj);
            var silderPage_li =$('#silder_page li',g.obj);
            silderPage_li.eq(0).addClass('current');
            if(opt.is_showTit){ //初始化圖片描述
                $('#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"); //懸浮時 停止自動動畫,trigger 起默認觸發作用
        },
          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; //判斷對象是否存在
    this.each(function () {
      if (this.usedSilder) return;
      var opt = $.extend({}, $.fn.silderDefaults, options); //合并已賦值參數
      this.usedSilder = $.extendSilder(this, opt);
    });
  }
})(jQuery);