/**
 * bxslider v4.1.2 - fully loaded, responsive content slider
 * http://bxslider.com
 *
 * copyright 2014, steven wanderski - http://stevenwanderski.com - http://bxcreative.com
 * written while drinking belgian ales and listening to jazz
 *
 * released under the mit license - http://opensource.org/licenses/mit
 */

;(function($){

 var plugin = {};

 var defaults = {

  // general
  mode: 'horizontal',// 'horizontal', 'vertical', 'fade' 定义slider滚动的方向，有三个值可供选择
  slideselector: '',
  infiniteloop: true,// 无限循环 
  hidecontrolonend: false,// 如果设置true，将会在最后一个幻灯片隐藏“next”，在最前面的幻灯片因此“prev” 
  speed: 500,// 过渡速度
  easing: null,
  slidemargin: 0,
  startslide: 0,
  randomstart: false,
  captions: false,// 包括图像字幕。标题是来自图像的title属性
  ticker: false,
  tickerhover: false,
  adaptiveheight: false,// 自动高度
  adaptiveheightspeed: 500,
  video: false,
  usecss: true,
  preloadimages: 'visible',
  responsive: true,
  slidezindex: 50,
  viewportclass: 'slidebox',

  // touch
  touchenabled: true,
  swipethreshold: 50,
  onetoonetouch: true,
  preventdefaultswipex: true,
  preventdefaultswipey: false,

  // pager
  pager: true,// 是否显示切换图标
  pagertype: 'full',//如果设置full，将显示1，2，3……，如果设置short，将显示1/
  pagershortseparator: ' / ',
  pagerselector: null,
  buildpager: null,
  pagercustom: null,

  // controls
  controls: false,// 是否显示“previous”和“next”按钮
  nexttext: '>',
  prevtext: '<',

  // auto
  auto: true,// 幻灯片自动滚动 
  pause: 4000,// 切换下一张速度
  autostart: true,
  autodirection: 'next',// 自动滚动的顺序'next', 'prev'
  autohover: false,// 设置鼠标mouseover将会使自动滚动暂停
  autodelay: 0,
  autoslideforonepage: false,

  // carousel
  minslides: 1,
  maxslides: 1,
  moveslides: 0,
  slidewidth: 0,

  // callbacks
  onsliderload: function() {},
  onslidebefore: function() {},
  onslideafter: function() {},
  onslidenext: function() {},
  onslideprev: function() {},
  onsliderresize: function() {}
 }

 $.fn.bxslider = function(options){

  if(this.length == 0) return this;

  // support mutltiple elements
  if(this.length > 1){
   this.each(function(){$(this).bxslider(options)});
   return this;
  }

  // create a namespace to be used throughout the plugin
  var slider = {};
  // set a reference to our slider element
  var el = this;
  plugin.el = this;

  /**
   * makes slideshow responsive
   */
  // first get the original window dimens (thanks alot ie)
  var windowwidth = $(window).width();
  var windowheight = $(window).height();



  /**
   * ===================================================================================
   * = private functions
   * ===================================================================================
   */

  /**
   * initializes namespace settings to be used throughout plugin
   */
  var init = function(){
   // merge user-supplied options with the defaults
   slider.settings = $.extend({}, defaults, options);
   // parse slidewidth setting
   slider.settings.slidewidth = parseint(slider.settings.slidewidth);
   // store the original children
   slider.children = el.children(slider.settings.slideselector);
   // check if actual number of slides is less than minslides / maxslides
   if(slider.children.length < slider.settings.minslides) slider.settings.minslides = slider.children.length;
   if(slider.children.length < slider.settings.maxslides) slider.settings.maxslides = slider.children.length;
   // if random start, set the startslide setting to random number
   if(slider.settings.randomstart) slider.settings.startslide = math.floor(math.random() * slider.children.length);
   // store active slide information
   slider.active = { index: slider.settings.startslide }
   // store if the slider is in carousel mode (displaying / moving multiple slides)
   slider.carousel = slider.settings.minslides > 1 || slider.settings.maxslides > 1;
   // if carousel, force preloadimages = 'all'
   if(slider.carousel) slider.settings.preloadimages = 'all';
   // calculate the min / max width thresholds based on min / max number of slides
   // used to setup and update carousel slides dimensions
   slider.minthreshold = (slider.settings.minslides * slider.settings.slidewidth) + ((slider.settings.minslides - 1) * slider.settings.slidemargin);
   slider.maxthreshold = (slider.settings.maxslides * slider.settings.slidewidth) + ((slider.settings.maxslides - 1) * slider.settings.slidemargin);
   // store the current state of the slider (if currently animating, working is true)
   slider.working = false;
   // initialize the controls object
   slider.controls = {};
   // initialize an auto interval
   slider.interval = null;
   // determine which property to use for transitions
   slider.animprop = slider.settings.mode == 'vertical' ? 'top' : 'left';
   // determine if hardware acceleration can be used
   slider.usingcss = slider.settings.usecss && slider.settings.mode != 'fade' && (function(){
    // create our test div element
    var div = document.createelement('div');
    // css transition properties
    var props = ['webkitperspective', 'mozperspective', 'operspective', 'msperspective'];
    // test for each property
    for(var i in props){
     if(div.style[props[i]] !== undefined){
      slider.cssprefix = props[i].replace('perspective', '').tolowercase();
      slider.animprop = '-' + slider.cssprefix + '-transform';
      return true;
     }
    }
    return false;
   }());
   // if vertical mode always make maxslides and minslides equal
   if(slider.settings.mode == 'vertical') slider.settings.maxslides = slider.settings.minslides;
   // save original style data
   el.data("origstyle", el.attr("style"));
   el.children(slider.settings.slideselector).each(function() {
     $(this).data("origstyle", $(this).attr("style"));
   });
   // perform all dom / css modifications
   setup();
  }

  /**
   * performs all dom and css modifications
   */
  var setup = function(){
   // wrap el in a wrapper
   el.wrap('<div class="' + slider.settings.viewportclass + '"></div>');
   // store a namspace reference to .bx-viewport
   slider.viewport = el.parent();
   // add a loading div to display while images are loading
   slider.loader = $('<div class="slideloading" />');
   slider.viewport.prepend(slider.loader);
   // set el to a massive width, to hold any needed slides
   // also strip any margin and padding from el
   el.css({
    width: slider.settings.mode == 'horizontal' ? (slider.children.length * 100 + 215) + '%' : 'auto',
    position: 'relative'
   });
   // if using css, add the easing property
   if(slider.usingcss && slider.settings.easing){
    el.css('-' + slider.cssprefix + '-transition-timing-function', slider.settings.easing);
   // if not using css and no easing value was supplied, use the default js animation easing (swing)
   }else if(!slider.settings.easing){
    slider.settings.easing = 'swing';
   }
   var slidesshowing = getnumberslidesshowing();
   // make modifications to the viewport (.bx-viewport)
   slider.viewport.css({
    width: '100%',
    overflow: 'hidden',
    position: 'relative'
   });
   slider.viewport.parent().css({
    maxwidth: getviewportmaxwidth()
   });
   // make modification to the wrapper (.bx-wrapper)
   if(!slider.settings.pager) {
    slider.viewport.parent().css({
    margin: '0 auto 0px'
    });
   }
   // apply css to all slider children
   slider.children.css({
    'float': slider.settings.mode == 'horizontal' ? 'left' : 'none',
    liststyle: 'none',
    position: 'relative'
   });
   // apply the calculated width after the float is applied to prevent scrollbar interference
   slider.children.css('width', getslidewidth());
   // if slidemargin is supplied, add the css
   if(slider.settings.mode == 'horizontal' && slider.settings.slidemargin > 0) slider.children.css('marginright', slider.settings.slidemargin);
   if(slider.settings.mode == 'vertical' && slider.settings.slidemargin > 0) slider.children.css('marginbottom', slider.settings.slidemargin);
   // if "fade" mode, add positioning and z-index css
   if(slider.settings.mode == 'fade'){
    slider.children.css({
     position: 'absolute',
     zindex: 0,
     display: 'none'
    });
    // prepare the z-index on the showing element
    slider.children.eq(slider.settings.startslide).css({zindex: slider.settings.slidezindex, display: 'block'});
   }
   // create an element to contain all slider controls (pager, start / stop, etc)
   slider.controls.el = $('<div class="controlbase" />');
   // if captions are requested, add them
   if(slider.settings.captions) appendcaptions();
   // check if startslide is last slide
   slider.active.last = slider.settings.startslide == getpagerqty() - 1;
   // if video is true, set up the fitvids plugin
   if(slider.settings.video) el.fitvids();
   // set the default preload selector (visible)
   var preloadselector = slider.children.eq(slider.settings.startslide);
   if (slider.settings.preloadimages == "all") preloadselector = slider.children;
   // only check for control addition if not in "ticker" mode
   if(!slider.settings.ticker){
    // if pager is requested, add it
    if(slider.settings.pager) appendpager();
    // if controls are requested, add them
    if(slider.settings.controls) appendcontrols();
    // if any control option is requested, add the controls wrapper
    if(slider.settings.controls || slider.settings.pager) slider.viewport.after(slider.controls.el);
   // if ticker mode, do not allow a pager
   }else{
    slider.settings.pager = false;
   }
   // preload all images, then perform final dom / css modifications that depend on images being loaded
   loadelements(preloadselector, start);
  }

  var loadelements = function(selector, callback){
   var total = selector.find('img, iframe').length;
   if (total == 0){
    callback();
    return;
   }
   var count = 0;
   selector.find('img, iframe').each(function(){
    $(this).one('load', function() {
      if(++count == total) callback();
    }).each(function() {
      if(this.complete) $(this).load();
    });
   });
  }

  /**
   * start the slider
   */
  var start = function(){
   // if infinite loop, prepare additional slides
   if(slider.settings.infiniteloop && slider.settings.mode != 'fade' && !slider.settings.ticker){
    var slice = slider.settings.mode == 'vertical' ? slider.settings.minslides : slider.settings.maxslides;
    var sliceappend = slider.children.slice(0, slice).clone().addclass('bx-clone');
    var sliceprepend = slider.children.slice(-slice).clone().addclass('bx-clone');
    el.append(sliceappend).prepend(sliceprepend);
   }
   // remove the loading dom element
   slider.loader.remove();
   // set the left / top position of "el"
   setslideposition();
   // if "vertical" mode, always use adaptiveheight to prevent odd behavior
   if (slider.settings.mode == 'vertical') slider.settings.adaptiveheight = true;
   // set the viewport height
   slider.viewport.height(getviewportheight());
   // make sure everything is positioned just right (same as a window resize)
   el.redrawslider();
   // onsliderload callback
   slider.settings.onsliderload(slider.active.index);
   // slider has been fully initialized
   slider.initialized = true;
   // bind the resize call to the window
   if (slider.settings.responsive) $(window).bind('resize', resizewindow);
   // if auto is true and has more than 1 page, start the show
   if (slider.settings.auto && slider.settings.autostart && (getpagerqty() > 1 || slider.settings.autoslideforonepage)) initauto();
   // if ticker is true, start the ticker
   if (slider.settings.ticker) initticker();
   // if pager is requested, make the appropriate pager link active
   if (slider.settings.pager) updatepageractive(slider.settings.startslide);
   // check for any updates to the controls (like hidecontrolonend updates)
   if (slider.settings.controls) updatedirectioncontrols();
   // if touchenabled is true, setup the touch events
   if (slider.settings.touchenabled && !slider.settings.ticker) inittouch();
  }

  /**
   * returns the calculated height of the viewport, used to determine either adaptiveheight or the maxheight value
   */
  var getviewportheight = function(){
   var height = 0;
   // first determine which children (slides) should be used in our height calculation
   var children = $();
   // if mode is not "vertical" and adaptiveheight is false, include all children
   if(slider.settings.mode != 'vertical' && !slider.settings.adaptiveheight){
    children = slider.children;
   }else{
    // if not carousel, return the single active child
    if(!slider.carousel){
     children = slider.children.eq(slider.active.index);
    // if carousel, return a slice of children
    }else{
     // get the individual slide index
     var currentindex = slider.settings.moveslides == 1 ? slider.active.index : slider.active.index * getmoveby();
     // add the current slide to the children
     children = slider.children.eq(currentindex);
     // cycle through the remaining "showing" slides
     for (i = 1; i <= slider.settings.maxslides - 1; i++){
      // if looped back to the start
      if(currentindex + i >= slider.children.length){
       children = children.add(slider.children.eq(i - 1));
      }else{
       children = children.add(slider.children.eq(currentindex + i));
      }
     }
    }
   }
   // if "vertical" mode, calculate the sum of the heights of the children
   if(slider.settings.mode == 'vertical'){
    children.each(function(index) {
      height += $(this).outerheight();
    });
    // add user-supplied margins
    if(slider.settings.slidemargin > 0){
     height += slider.settings.slidemargin * (slider.settings.minslides - 1);
    }
   // if not "vertical" mode, calculate the max height of the children
   }else{
    height = math.max.apply(math, children.map(function(){
     return $(this).outerheight(false);
    }).get());
   }

   if(slider.viewport.css('box-sizing') == 'border-box'){
    height += parsefloat(slider.viewport.css('padding-top')) + parsefloat(slider.viewport.css('padding-bottom')) +
       parsefloat(slider.viewport.css('border-top-width')) + parsefloat(slider.viewport.css('border-bottom-width'));
   }else if(slider.viewport.css('box-sizing') == 'padding-box'){
    height += parsefloat(slider.viewport.css('padding-top')) + parsefloat(slider.viewport.css('padding-bottom'));
   }

   return height;
  }

  /**
   * returns the calculated width to be used for the outer wrapper / viewport
   */
  var getviewportmaxwidth = function(){
   var width = '100%';
   if(slider.settings.slidewidth > 0){
    if(slider.settings.mode == 'horizontal'){
     width = (slider.settings.maxslides * slider.settings.slidewidth) + ((slider.settings.maxslides - 1) * slider.settings.slidemargin);
    }else{
     width = slider.settings.slidewidth;
    }
   }
   return width;
  }

  /**
   * returns the calculated width to be applied to each slide
   */
  var getslidewidth = function(){
   // start with any user-supplied slide width
   var newelwidth = slider.settings.slidewidth;
   // get the current viewport width
   var wrapwidth = slider.viewport.width();
   // if slide width was not supplied, or is larger than the viewport use the viewport width
   if(slider.settings.slidewidth == 0 ||
    (slider.settings.slidewidth > wrapwidth && !slider.carousel) ||
    slider.settings.mode == 'vertical'){
    newelwidth = wrapwidth;
   // if carousel, use the thresholds to determine the width
   }else if(slider.settings.maxslides > 1 && slider.settings.mode == 'horizontal'){
    if(wrapwidth > slider.maxthreshold){
     // newelwidth = (wrapwidth - (slider.settings.slidemargin * (slider.settings.maxslides - 1))) / slider.settings.maxslides;
    }else if(wrapwidth < slider.minthreshold){
     newelwidth = (wrapwidth - (slider.settings.slidemargin * (slider.settings.minslides - 1))) / slider.settings.minslides;
    }
   }
   return newelwidth;
  }

  /**
   * returns the number of slides currently visible in the viewport (includes partially visible slides)
   */
  var getnumberslidesshowing = function(){
   var slidesshowing = 1;
   if(slider.settings.mode == 'horizontal' && slider.settings.slidewidth > 0){
    // if viewport is smaller than minthreshold, return minslides
    if(slider.viewport.width() < slider.minthreshold){
     slidesshowing = slider.settings.minslides;
    // if viewport is larger than minthreshold, return maxslides
    }else if(slider.viewport.width() > slider.maxthreshold){
     slidesshowing = slider.settings.maxslides;
    // if viewport is between min / max thresholds, divide viewport width by first child width
    }else{
     var childwidth = slider.children.first().width() + slider.settings.slidemargin;
     slidesshowing = math.floor((slider.viewport.width() +
      slider.settings.slidemargin) / childwidth);
    }
   // if "vertical" mode, slides showing will always be minslides
   }else if(slider.settings.mode == 'vertical'){
    slidesshowing = slider.settings.minslides;
   }
   return slidesshowing;
  }

  /**
   * returns the number of pages (one full viewport of slides is one "page")
   */
  var getpagerqty = function(){
   var pagerqty = 0;
   // if moveslides is specified by the user
   if(slider.settings.moveslides > 0){
    if(slider.settings.infiniteloop){
     pagerqty = math.ceil(slider.children.length / getmoveby());
    }else{
     // use a while loop to determine pages
     var breakpoint = 0;
     var counter = 0
     // when breakpoint goes above children length, counter is the number of pages
     while (breakpoint < slider.children.length){
      ++pagerqty;
      breakpoint = counter + getnumberslidesshowing();
      counter += slider.settings.moveslides <= getnumberslidesshowing() ? slider.settings.moveslides : getnumberslidesshowing();
     }
    }
   // if moveslides is 0 (auto) divide children length by sides showing, then round up
   }else{
    pagerqty = math.ceil(slider.children.length / getnumberslidesshowing());
   }
   return pagerqty;
  }

  /**
   * returns the number of indivual slides by which to shift the slider
   */
  var getmoveby = function(){
   // if moveslides was set by the user and moveslides is less than number of slides showing
   if(slider.settings.moveslides > 0 && slider.settings.moveslides <= getnumberslidesshowing()){
    return slider.settings.moveslides;
   }
   // if moveslides is 0 (auto)
   return getnumberslidesshowing();
  }

  /**
   * sets the slider's (el) left or top position
   */
  var setslideposition = function(){
   // if last slide, not infinite loop, and number of children is larger than specified maxslides
   if(slider.children.length > slider.settings.maxslides && slider.active.last && !slider.settings.infiniteloop){
    if (slider.settings.mode == 'horizontal'){
     // get the last child's position
     var lastchild = slider.children.last();
     var position = lastchild.position();
     // set the left position
     setpositionproperty(-(position.left - (slider.viewport.width() - lastchild.outerwidth())), 'reset', 0);
    }else if(slider.settings.mode == 'vertical'){
     // get the last showing index's position
     var lastshowingindex = slider.children.length - slider.settings.minslides;
     var position = slider.children.eq(lastshowingindex).position();
     // set the top position
     setpositionproperty(-position.top, 'reset', 0);
    }
   // if not last slide
   }else{
    // get the position of the first showing slide
    var position = slider.children.eq(slider.active.index * getmoveby()).position();
    // check for last slide
    if (slider.active.index == getpagerqty() - 1) slider.active.last = true;
    // set the repective position
    if (position != undefined){
     if (slider.settings.mode == 'horizontal') setpositionproperty(-position.left, 'reset', 0);
     else if (slider.settings.mode == 'vertical') setpositionproperty(-position.top, 'reset', 0);
    }
   }
  }

  /**
   * sets the el's animating property position (which in turn will sometimes animate el).
   * if using css, sets the transform property. if not using css, sets the top / left property.
   *
   * @param value (int)
   *  - the animating property's value
   *
   * @param type (string) 'slider', 'reset', 'ticker'
   *  - the type of instance for which the function is being
   *
   * @param duration (int)
   *  - the amount of time (in ms) the transition should occupy
   *
   * @param params (array) optional
   *  - an optional parameter containing any variables that need to be passed in
   */
  var setpositionproperty = function(value, type, duration, params){
   // use css transform
   if(slider.usingcss){
    // determine the translate3d value
    var propvalue = slider.settings.mode == 'vertical' ? 'translate3d(0, ' + value + 'px, 0)' : 'translate3d(' + value + 'px, 0, 0)';
    // add the css transition-duration
    el.css('-' + slider.cssprefix + '-transition-duration', duration / 1000 + 's');
    if(type == 'slide'){
     // set the property value
     el.css(slider.animprop, propvalue);
     // bind a callback method - executes when css transition completes
     el.bind('transitionend webkittransitionend otransitionend mstransitionend', function(){
      // unbind the callback
      el.unbind('transitionend webkittransitionend otransitionend mstransitionend');
      updateafterslidetransition();
     });
    }else if(type == 'reset'){
     el.css(slider.animprop, propvalue);
    }else if(type == 'ticker'){
     // make the transition use 'linear'
     el.css('-' + slider.cssprefix + '-transition-timing-function', 'linear');
     el.css(slider.animprop, propvalue);
     // bind a callback method - executes when css transition completes
     el.bind('transitionend webkittransitionend otransitionend mstransitionend', function(){
      // unbind the callback
      el.unbind('transitionend webkittransitionend otransitionend mstransitionend');
      // reset the position
      setpositionproperty(params['resetvalue'], 'reset', 0);
      // start the loop again
      tickerloop();
     });
    }
   // use js animate
   }else{
    var animateobj = {};
    animateobj[slider.animprop] = value;
    if(type == 'slide'){
     el.animate(animateobj, duration, slider.settings.easing, function(){
      updateafterslidetransition();
     });
    }else if(type == 'reset'){
     el.css(slider.animprop, value)
    }else if(type == 'ticker'){
     el.animate(animateobj, speed, 'linear', function(){
      setpositionproperty(params['resetvalue'], 'reset', 0);
      // run the recursive loop after animation
      tickerloop();
     });
    }
   }
  }

  /**
   * populates the pager with proper amount of pages
   */
  var populatepager = function(){
   var pagerhtml = '';
   var pagerqty = getpagerqty();
   // loop through each pager item
   for(var i=0; i < pagerqty; i++){
    var linkcontent = '';
    // if a buildpager function is supplied, use it to get pager link value, else use index + 1
    if(slider.settings.buildpager && $.isfunction(slider.settings.buildpager)){
     linkcontent = slider.settings.buildpager(i);
     slider.pagerel.addclass('controlcustom');
    }else{
     linkcontent = i + 1;
     slider.pagerel.addclass('controldefault');
    }
    // var linkcontent = slider.settings.buildpager && $.isfunction(slider.settings.buildpager) ? slider.settings.buildpager(i) : i + 1;
    // add the markup to the string
    pagerhtml += '<div class="control"><a href="" data-slide-index="' + i + '" class="controllink">' + linkcontent + '</a></div>';
   };
   // populate the pager element with pager links
   slider.pagerel.html(pagerhtml);
  }

  /**
   * appends the pager to the controls element
   */
  var appendpager = function(){
   if(!slider.settings.pagercustom){
    // create the pager dom element
    slider.pagerel = $('<div class="controlbox" />');
    // if a pager selector was supplied, populate it with the pager
    if(slider.settings.pagerselector){
     $(slider.settings.pagerselector).html(slider.pagerel);
    // if no pager selector was supplied, add it after the wrapper
    }else{
     slider.controls.el.addclass('hascontrol').append(slider.pagerel);
    }
    // populate the pager
    populatepager();
   }else{
    slider.pagerel = $(slider.settings.pagercustom);
   }
   // assign the pager click binding
   slider.pagerel.on('click', 'a', clickpagerbind);
  }

  /**
   * appends prev / next controls to the controls element
   */
  var appendcontrols = function(){
   slider.controls.next = $('<a class="arrownext" href="">' + slider.settings.nexttext + '</a>');
   slider.controls.prev = $('<a class="arrowprev" href="">' + slider.settings.prevtext + '</a>');
   // bind click actions to the controls
   slider.controls.next.bind('click', clicknextbind);
   slider.controls.prev.bind('click', clickprevbind);
   // if nextslector was supplied, populate it
   if(slider.settings.nextselector){
    $(slider.settings.nextselector).append(slider.controls.next);
   }
   // if prevslector was supplied, populate it
   if(slider.settings.prevselector){
    $(slider.settings.prevselector).append(slider.controls.prev);
   }
   // if no custom selectors were supplied
   if(!slider.settings.nextselector && !slider.settings.prevselector){
    // add the controls to the dom
    slider.controls.directionel = $('<div class="arrowbox" />');
    // add the control elements to the directionel
    slider.controls.directionel.append(slider.controls.prev).append(slider.controls.next);
    // slider.viewport.append(slider.controls.directionel);
    slider.controls.el.addclass('hasarrowbox').append(slider.controls.directionel);
   }
  }

  /**
   * appends image captions to the dom
   */
  var appendcaptions = function(){
   // cycle through each child
   slider.children.each(function(index){
    // get the image title attribute
    var title = $(this).find('img:first').attr('title');
    // append the caption
    if (title != undefined && ('' + title).length) {
                    $(this).append('<div class="slidetitle"><span>' + title + '</span></div>');
                }
   });
  }

  /**
   * click next binding
   *
   * @param e (event)
   *  - dom event object
   */
  var clicknextbind = function(e){
   // if auto show is running, stop it
   // if (slider.settings.auto) el.stopauto();//上一图片时停止自动播放
   el.gotonextslide();
   e.preventdefault();
  }

  /**
   * click prev binding
   *
   * @param e (event)
   *  - dom event object
   */
  var clickprevbind = function(e){
   // if auto show is running, stop it
   // if (slider.settings.auto) el.stopauto();//下一图片时停止自动播放
   el.gotoprevslide();
   e.preventdefault();
  }

  /**
   * click pager binding
   *
   * @param e (event)
   *  - dom event object
   */
  var clickpagerbind = function(e){
   // if auto show is running, stop it
   // if (slider.settings.auto) el.stopauto();//当按控制按钮时停止自动播放
   var pagerlink = $(e.currenttarget);
   if(pagerlink.attr('data-slide-index') !== undefined){
    var pagerindex = parseint(pagerlink.attr('data-slide-index'));
    // if clicked pager link is not active, continue with the gotoslide call
    if(pagerindex != slider.active.index) el.gotoslide(pagerindex);
    e.preventdefault();
   }
  }

  /**
   * updates the pager links with an active class
   *
   * @param slideindex (int)
   *  - index of slide to make active
   */
  var updatepageractive = function(slideindex){
   // if "short" pager type
   var len = slider.children.length; // nb of children
   if(slider.settings.pagertype == 'short'){
    if(slider.settings.maxslides > 1) {
     len = math.ceil(slider.children.length/slider.settings.maxslides);
    }
    slider.pagerel.html( (slideindex + 1) + slider.settings.pagershortseparator + len);
    return;
   }
   // remove all pager active classes
   slider.pagerel.find('a').removeclass('active');
   // apply the active class for all pagers
   slider.pagerel.each(function(i, el) { $(el).find('a').eq(slideindex).addclass('active'); });
  }

  /**
   * performs needed actions after a slide transition
   */
  var updateafterslidetransition = function(){
   // if infinte loop is true
   if(slider.settings.infiniteloop){
    var position = '';
    // first slide
    if(slider.active.index == 0){
     // set the new position
     position = slider.children.eq(0).position();
    // carousel, last slide
    }else if(slider.active.index == getpagerqty() - 1 && slider.carousel){
     position = slider.children.eq((getpagerqty() - 1) * getmoveby()).position();
    // last slide
    }else if(slider.active.index == slider.children.length - 1){
     position = slider.children.eq(slider.children.length - 1).position();
    }
    if(position){
     if (slider.settings.mode == 'horizontal') { setpositionproperty(-position.left, 'reset', 0); }
     else if (slider.settings.mode == 'vertical') { setpositionproperty(-position.top, 'reset', 0); }
    }
   }
   // declare that the transition is complete
   slider.working = false;
   // onslideafter callback
   slider.settings.onslideafter(slider.children.eq(slider.active.index), slider.oldindex, slider.active.index);
  }

  /**
   * updates the direction controls (checks if either should be hidden)
   */
  var updatedirectioncontrols = function(){
   if(getpagerqty() == 1){
    slider.controls.prev.addclass('disabled');
    slider.controls.next.addclass('disabled');
   }else if(!slider.settings.infiniteloop && slider.settings.hidecontrolonend){
    // if first slide
    if (slider.active.index == 0){
     slider.controls.prev.addclass('disabled');
     slider.controls.next.removeclass('disabled');
    // if last slide
    }else if(slider.active.index == getpagerqty() - 1){
     slider.controls.next.addclass('disabled');
     slider.controls.prev.removeclass('disabled');
    // if any slide in the middle
    }else{
     slider.controls.prev.removeclass('disabled');
     slider.controls.next.removeclass('disabled');
    }
   }
  }

  /**
   * initialzes the auto process
   */
  var initauto = function(){
   // if autodelay was supplied, launch the auto show using a settimeout() call
   if(slider.settings.autodelay > 0){
    var timeout = settimeout(el.startauto, slider.settings.autodelay);
   // if autodelay was not supplied, start the auto show normally
   }else{
    el.startauto();
   }
   // if autohover is requested
   if(slider.settings.autohover){
    // on el hover
    el.hover(function(){
     // if the auto show is currently playing (has an active interval)
     if(slider.interval){
      // stop the auto show and pass true agument which will prevent control update
      el.stopauto(true);
      // create a new autopaused value which will be used by the relative "mouseout" event
      slider.autopaused = true;
     }
    }, function(){
     // if the autopaused value was created be the prior "mouseover" event
     if(slider.autopaused){
      // start the auto show and pass true agument which will prevent control update
      el.startauto(true);
      // reset the autopaused value
      slider.autopaused = null;
     }
    });
   }
  }

  /**
   * initialzes the ticker process
   */
  var initticker = function(){
   var startposition = 0;
   // if autodirection is "next", append a clone of the entire slider
   if(slider.settings.autodirection == 'next'){
    el.append(slider.children.clone().addclass('bx-clone'));
   // if autodirection is "prev", prepend a clone of the entire slider, and set the left position
   }else{
    el.prepend(slider.children.clone().addclass('bx-clone'));
    var position = slider.children.first().position();
    startposition = slider.settings.mode == 'horizontal' ? -position.left : -position.top;
   }
   setpositionproperty(startposition, 'reset', 0);
   // do not allow controls in ticker mode
   slider.settings.pager = false;
   slider.settings.controls = false;
   // if autohover is requested
   if(slider.settings.tickerhover && !slider.usingcss){
    // on el hover
    slider.viewport.hover(function(){
     el.stop();
    }, function(){
     // calculate the total width of children (used to calculate the speed ratio)
     var totaldimens = 0;
     slider.children.each(function(index){
       totaldimens += slider.settings.mode == 'horizontal' ? $(this).outerwidth(true) : $(this).outerheight(true);
     });
     // calculate the speed ratio (used to determine the new speed to finish the paused animation)
     var ratio = slider.settings.speed / totaldimens;
     // determine which property to use
     var property = slider.settings.mode == 'horizontal' ? 'left' : 'top';
     // calculate the new speed
     var newspeed = ratio * (totaldimens - (math.abs(parseint(el.css(property)))));
     tickerloop(newspeed);
    });
   }
   // start the ticker loop
   tickerloop();
  }

  /**
   * runs a continuous loop, news ticker-style
   */
  var tickerloop = function(resumespeed){
   speed = resumespeed ? resumespeed : slider.settings.speed;
   var position = {left: 0, top: 0};
   var reset = {left: 0, top: 0};
   // if "next" animate left position to last child, then reset left to 0
   if(slider.settings.autodirection == 'next'){
    position = el.find('.bx-clone').first().position();
   // if "prev" animate left position to 0, then reset left to first non-clone child
   }else{
    reset = slider.children.first().position();
   }
   var animateproperty = slider.settings.mode == 'horizontal' ? -position.left : -position.top;
   var resetvalue = slider.settings.mode == 'horizontal' ? -reset.left : -reset.top;
   var params = {resetvalue: resetvalue};
   setpositionproperty(animateproperty, 'ticker', speed, params);
  }

  /**
   * initializes touch events
   */
  var inittouch = function(){
   // initialize object to contain all touch values
   slider.touch = {
    start: {x: 0, y: 0},
    end: {x: 0, y: 0}
   }
   slider.viewport.bind('touchstart', ontouchstart);
  }

  /**
   * event handler for "touchstart"
   *
   * @param e (event)
   *  - dom event object
   */
  var ontouchstart = function(e){
   if(slider.working){
    e.preventdefault();
   }else{
    // record the original position when touch starts
    slider.touch.originalpos = el.position();
    var orig = e.originalevent;
    // record the starting touch x, y coordinates
    slider.touch.start.x = orig.changedtouches[0].pagex;
    slider.touch.start.y = orig.changedtouches[0].pagey;
    // bind a "touchmove" event to the viewport
    slider.viewport.bind('touchmove', ontouchmove);
    // bind a "touchend" event to the viewport
    slider.viewport.bind('touchend', ontouchend);
   }
  }

  /**
   * event handler for "touchmove"
   *
   * @param e (event)
   *  - dom event object
   */
  var ontouchmove = function(e){
   var orig = e.originalevent;
   // if scrolling on y axis, do not prevent default
   var xmovement = math.abs(orig.changedtouches[0].pagex - slider.touch.start.x);
   var ymovement = math.abs(orig.changedtouches[0].pagey - slider.touch.start.y);
   // x axis swipe
   if((xmovement * 3) > ymovement && slider.settings.preventdefaultswipex){
    e.preventdefault();
   // y axis swipe
   }else if((ymovement * 3) > xmovement && slider.settings.preventdefaultswipey){
    e.preventdefault();
   }
   if(slider.settings.mode != 'fade' && slider.settings.onetoonetouch){
    var value = 0;
    // if horizontal, drag along x axis
    if(slider.settings.mode == 'horizontal'){
     var change = orig.changedtouches[0].pagex - slider.touch.start.x;
     value = slider.touch.originalpos.left + change;
    // if vertical, drag along y axis
    }else{
     var change = orig.changedtouches[0].pagey - slider.touch.start.y;
     value = slider.touch.originalpos.top + change;
    }
    setpositionproperty(value, 'reset', 0);
   }
  }

  /**
   * event handler for "touchend"
   *
   * @param e (event)
   *  - dom event object
   */
  var ontouchend = function(e){
   slider.viewport.unbind('touchmove', ontouchmove);
   var orig = e.originalevent;
   var value = 0;
   // record end x, y positions
   slider.touch.end.x = orig.changedtouches[0].pagex;
   slider.touch.end.y = orig.changedtouches[0].pagey;
   // if fade mode, check if absolute x distance clears the threshold
   if(slider.settings.mode == 'fade'){
    var distance = math.abs(slider.touch.start.x - slider.touch.end.x);
    if(distance >= slider.settings.swipethreshold){
     slider.touch.start.x > slider.touch.end.x ? el.gotonextslide() : el.gotoprevslide();
     // el.stopauto();//当触屏滑动图片时停止自动播放
    }
   // not fade mode
   }else{
    var distance = 0;
    // calculate distance and el's animate property
    if(slider.settings.mode == 'horizontal'){
     distance = slider.touch.end.x - slider.touch.start.x;
     value = slider.touch.originalpos.left;
    }else{
     distance = slider.touch.end.y - slider.touch.start.y;
     value = slider.touch.originalpos.top;
    }
    // if not infinite loop and first / last slide, do not attempt a slide transition
    if(!slider.settings.infiniteloop && ((slider.active.index == 0 && distance > 0) || (slider.active.last && distance < 0))){
     setpositionproperty(value, 'reset', 200);
    }else{
     // check if distance clears threshold
     if(math.abs(distance) >= slider.settings.swipethreshold){
      distance < 0 ? el.gotonextslide() : el.gotoprevslide();
      // el.stopauto();//当触屏滑动图片时停止自动播放
     }else{
      // el.animate(property, 200);
      setpositionproperty(value, 'reset', 200);
     }
    }
   }
   slider.viewport.unbind('touchend', ontouchend);
  }

  /**
   * window resize event callback
   */
  var resizewindow = function(e){
   // don't do anything if slider isn't initialized.
   if(!slider.initialized) return;
   // get the new window dimens (again, thank you ie)
   var windowwidthnew = $(window).width();
   var windowheightnew = $(window).height();
   // make sure that it is a true window resize
   // *we must check this because our dinosaur friend ie fires a window resize event when certain dom elements
   // are resized. can you just die already?*
   if(windowwidth != windowwidthnew || windowheight != windowheightnew){
    // set the new window dimens
    windowwidth = windowwidthnew;
    windowheight = windowheightnew;
    // update all dynamic elements
    el.redrawslider();
    // call user resize handler
    slider.settings.onsliderresize.call(el, slider.active.index);
   }
  }

  /**
   * ===================================================================================
   * = public functions
   * ===================================================================================
   */

  /**
   * performs slide transition to the specified slide
   *
   * @param slideindex (int)
   *  - the destination slide's index (zero-based)
   *
   * @param direction (string)
   *  - internal use only - the direction of travel ("prev" / "next")
   */
  el.gotoslide = function(slideindex, direction){
   // if plugin is currently in motion, ignore request
   if(slider.working || slider.active.index == slideindex) return;
   // declare that plugin is in motion
   slider.working = true;
   // store the old index
   slider.oldindex = slider.active.index;
   // if slideindex is less than zero, set active index to last child (this happens during infinite loop)
   if(slideindex < 0){
    slider.active.index = getpagerqty() - 1;
   // if slideindex is greater than children length, set active index to 0 (this happens during infinite loop)
   }else if(slideindex >= getpagerqty()){
    slider.active.index = 0;
   // set active index to requested slide
   }else{
    slider.active.index = slideindex;
   }
   // onslidebefore, onslidenext, onslideprev callbacks
   slider.settings.onslidebefore(slider.children.eq(slider.active.index), slider.oldindex, slider.active.index);
   if(direction == 'next'){
    slider.settings.onslidenext(slider.children.eq(slider.active.index), slider.oldindex, slider.active.index);
   }else if(direction == 'prev'){
    slider.settings.onslideprev(slider.children.eq(slider.active.index), slider.oldindex, slider.active.index);
   }
   // check if last slide
   slider.active.last = slider.active.index >= getpagerqty() - 1;
   // update the pager with active class
   if(slider.settings.pager) updatepageractive(slider.active.index);
   // // check for direction control update
   if(slider.settings.controls) updatedirectioncontrols();
   // if slider is set to mode: "fade"
   if(slider.settings.mode == 'fade'){
    // if adaptiveheight is true and next height is different from current height, animate to the new height
    if(slider.settings.adaptiveheight && slider.viewport.height() != getviewportheight()){
     slider.viewport.animate({height: getviewportheight()}, slider.settings.adaptiveheightspeed);
    }
    // fade out the visible child and reset its z-index value
    slider.children.filter(':visible').fadeout(slider.settings.speed).css({zindex: 0});
    // fade in the newly requested slide
    slider.children.eq(slider.active.index).css('zindex', slider.settings.slidezindex+1).fadein(slider.settings.speed, function(){
     $(this).css('zindex', slider.settings.slidezindex);
     updateafterslidetransition();
    });
   // slider mode is not "fade"
   }else{
    // if adaptiveheight is true and next height is different from current height, animate to the new height
    if(slider.settings.adaptiveheight && slider.viewport.height() != getviewportheight()){
     slider.viewport.animate({height: getviewportheight()}, slider.settings.adaptiveheightspeed);
    }
    var moveby = 0;
    var position = {left: 0, top: 0};
    // if carousel and not infinite loop
    if(!slider.settings.infiniteloop && slider.carousel && slider.active.last){
     if(slider.settings.mode == 'horizontal'){
      // get the last child position
      var lastchild = slider.children.eq(slider.children.length - 1);
      position = lastchild.position();
      // calculate the position of the last slide
      moveby = slider.viewport.width() - lastchild.outerwidth();
     }else{
      // get last showing index position
      var lastshowingindex = slider.children.length - slider.settings.minslides;
      position = slider.children.eq(lastshowingindex).position();
     }
     // horizontal carousel, going previous while on first slide (infiniteloop mode)
    }else if(slider.carousel && slider.active.last && direction == 'prev'){
     // get the last child position
     var eq = slider.settings.moveslides == 1 ? slider.settings.maxslides - getmoveby() : ((getpagerqty() - 1) * getmoveby()) - (slider.children.length - slider.settings.maxslides);
     var lastchild = el.children('.bx-clone').eq(eq);
     position = lastchild.position();
    // if infinite loop and "next" is clicked on the last slide
    }else if(direction == 'next' && slider.active.index == 0){
     // get the last clone position
     position = el.find('> .bx-clone').eq(slider.settings.maxslides).position();
     slider.active.last = false;
    // normal non-zero requests
    }else if(slideindex >= 0){
     var requestel = slideindex * getmoveby();
     position = slider.children.eq(requestel).position();
    }

    /* if the position doesn't exist
     * (e.g. if you destroy the slider on a next click),
     * it doesn't throw an error.
     */
    if ("undefined" !== typeof(position)) {
     var value = slider.settings.mode == 'horizontal' ? -(position.left - moveby) : -position.top;
     // plugin values to be animated
     setpositionproperty(value, 'slide', slider.settings.speed);
    }
   }
  }

  /**
   * transitions to the next slide in the show
   */
  el.gotonextslide = function(){
   // if infiniteloop is false and last page is showing, disregard call
   if (!slider.settings.infiniteloop && slider.active.last) return;
   var pagerindex = parseint(slider.active.index) + 1;
   el.gotoslide(pagerindex, 'next');
  }

  /**
   * transitions to the prev slide in the show
   */
  el.gotoprevslide = function(){
   // if infiniteloop is false and last page is showing, disregard call
   if (!slider.settings.infiniteloop && slider.active.index == 0) return;
   var pagerindex = parseint(slider.active.index) - 1;
   el.gotoslide(pagerindex, 'prev');
  }

  /**
   * starts the auto show
   *
   * @param preventcontrolupdate (boolean)
   *  - if true, auto controls state will not be updated
   */
  el.startauto = function(preventcontrolupdate){
   // if an interval already exists, disregard call
   if(slider.interval) return;
   // create an interval
   slider.interval = setinterval(function(){
    slider.settings.autodirection == 'next' ? el.gotonextslide() : el.gotoprevslide();
   }, slider.settings.pause);
   // if auto controls are displayed and preventcontrolupdate is not true
   if (slider.settings.autocontrols && preventcontrolupdate != true) updateautocontrols('stop');
  }

  /**
   * stops the auto show
   *
   * @param preventcontrolupdate (boolean)
   *  - if true, auto controls state will not be updated
   */
  el.stopauto = function(preventcontrolupdate){
   // if no interval exists, disregard call
   if(!slider.interval) return;
   // clear the interval
   clearinterval(slider.interval);
   slider.interval = null;
   // if auto controls are displayed and preventcontrolupdate is not true
   if (slider.settings.autocontrols && preventcontrolupdate != true) updateautocontrols('start');
  }

  /**
   * returns current slide index (zero-based)
   */
  el.getcurrentslide = function(){
   return slider.active.index;
  }

  /**
   * returns current slide element
   */
  el.getcurrentslideelement = function(){
   return slider.children.eq(slider.active.index);
  }

  /**
   * returns number of slides in show
   */
  el.getslidecount = function(){
   return slider.children.length;
  }

  /**
   * update all dynamic slider elements
   */
  el.redrawslider = function(){
   // resize all children in ratio to new screen size
   slider.children.add(el.find('.bx-clone')).width(getslidewidth());
   // adjust the height
   slider.viewport.css('height', getviewportheight());
   // update the slide position
   if(!slider.settings.ticker) setslideposition();
   // if active.last was true before the screen resize, we want
   // to keep it last no matter what screen size we end on
   if (slider.active.last) slider.active.index = getpagerqty() - 1;
   // if the active index (page) no longer exists due to the resize, simply set the index as last
   if (slider.active.index >= getpagerqty()) slider.active.last = true;
   // if a pager is being displayed and a custom pager is not being used, update it
   if(slider.settings.pager && !slider.settings.pagercustom){
    populatepager();
    updatepageractive(slider.active.index);
   }
  }

  /**
   * destroy the current instance of the slider (revert everything back to original state)
   */
  el.destroyslider = function(){
   // don't do anything if slider has already been destroyed
   if(!slider.initialized) return;
   slider.initialized = false;
   $('.bx-clone', this).remove();
   slider.children.each(function() {
    $(this).data("origstyle") != undefined ? $(this).attr("style", $(this).data("origstyle")) : $(this).removeattr('style');
   });
   $(this).data("origstyle") != undefined ? this.attr("style", $(this).data("origstyle")) : $(this).removeattr('style');
   $(this).unwrap().unwrap();
   if(slider.controls.el) slider.controls.el.remove();
   if(slider.controls.next) slider.controls.next.remove();
   if(slider.controls.prev) slider.controls.prev.remove();
   if(slider.pagerel && slider.settings.controls) slider.pagerel.remove();
   $('.slidetitle', this).remove();
   if(slider.controls.autoel) slider.controls.autoel.remove();
   clearinterval(slider.interval);
   if(slider.settings.responsive) $(window).unbind('resize', resizewindow);
  }

  /**
   * reload the slider (revert all dom changes, and re-initialize)
   */
  el.reloadslider = function(settings){
   if (settings != undefined) options = settings;
   el.destroyslider();
   init();
  }

  init();

  // returns the current jquery object
  return this;
 }

})(jquery);