/* ========================================================================

   * Bootstrap: affix.js v3.3.7

   * http://getbootstrap.com/javascript/#affix
   * ========================================================================

   * Copyright 2011-2016 Twitter, Inc.
   * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)

   * ======================================================================== */

  +function ($) {
    'use strict';

  
    // AFFIX CLASS DEFINITION
    // ======================
  
    var Affix = function (element, options) {
      this.options = $.extend({}, Affix.DEFAULTS, options)

  
      this.$target = $(this.options.target)

        .on('scroll.bs.affix.data-api', $.proxy(this.checkPosition, this))
        .on('click.bs.affix.data-api',  $.proxy(this.checkPositionWithEventLoop, this))

      this.$element     = $(element)
      this.affixed      = null
      this.unpin        = null
      this.pinnedOffset = null

  
      this.checkPosition()
    }

    Affix.VERSION  = '3.3.7'
  
    Affix.RESET    = 'affix affix-top affix-bottom'

  
    Affix.DEFAULTS = {

      offset: 0,
      target: window
    }
  
    Affix.prototype.getState = function (scrollHeight, height, offsetTop, offsetBottom) {
      var scrollTop    = this.$target.scrollTop()
      var position     = this.$element.offset()
      var targetHeight = this.$target.height()
  
      if (offsetTop != null && this.affixed == 'top') return scrollTop < offsetTop ? 'top' : false
  
      if (this.affixed == 'bottom') {
        if (offsetTop != null) return (scrollTop + this.unpin <= position.top) ? false : 'bottom'
        return (scrollTop + targetHeight <= scrollHeight - offsetBottom) ? false : 'bottom'
      }
  
      var initializing   = this.affixed == null
      var colliderTop    = initializing ? scrollTop : position.top
      var colliderHeight = initializing ? targetHeight : height
  
      if (offsetTop != null && scrollTop <= offsetTop) return 'top'
      if (offsetBottom != null && (colliderTop + colliderHeight >= scrollHeight - offsetBottom)) return 'bottom'
  
      return false
    }
  
    Affix.prototype.getPinnedOffset = function () {
      if (this.pinnedOffset) return this.pinnedOffset
      this.$element.removeClass(Affix.RESET).addClass('affix')
      var scrollTop = this.$target.scrollTop()
      var position  = this.$element.offset()
      return (this.pinnedOffset = position.top - scrollTop)

    }
  
    Affix.prototype.checkPositionWithEventLoop = function () {
      setTimeout($.proxy(this.checkPosition, this), 1)
    }
  
    Affix.prototype.checkPosition = function () {
      if (!this.$element.is(':visible')) return

      var height       = this.$element.height()

      var offset       = this.options.offset
      var offsetTop    = offset.top
      var offsetBottom = offset.bottom

      var scrollHeight = Math.max($(document).height(), $(document.body).height())

  
      if (typeof offset != 'object')         offsetBottom = offsetTop = offset

      if (typeof offsetTop == 'function')    offsetTop    = offset.top(this.$element)
      if (typeof offsetBottom == 'function') offsetBottom = offset.bottom(this.$element)

      var affix = this.getState(scrollHeight, height, offsetTop, offsetBottom)

      if (this.affixed != affix) {
        if (this.unpin != null) this.$element.css('top', '')

        var affixType = 'affix' + (affix ? '-' + affix : '')
        var e         = $.Event(affixType + '.bs.affix')

        this.$element.trigger(e)
  
        if (e.isDefaultPrevented()) return
  
        this.affixed = affix
        this.unpin = affix == 'bottom' ? this.getPinnedOffset() : null
  
        this.$element
          .removeClass(Affix.RESET)
          .addClass(affixType)
          .trigger(affixType.replace('affix', 'affixed') + '.bs.affix')
      }

  
      if (affix == 'bottom') {

        this.$element.offset({
          top: scrollHeight - height - offsetBottom
        })

      }
    }
  
  
    // AFFIX PLUGIN DEFINITION
    // =======================

    function Plugin(option) {

      return this.each(function () {
        var $this   = $(this)
        var data    = $this.data('bs.affix')
        var options = typeof option == 'object' && option
  
        if (!data) $this.data('bs.affix', (data = new Affix(this, options)))
        if (typeof option == 'string') data[option]()
      })
    }

    var old = $.fn.affix
  
    $.fn.affix             = Plugin

    $.fn.affix.Constructor = Affix
  
  
    // AFFIX NO CONFLICT
    // =================
  
    $.fn.affix.noConflict = function () {
      $.fn.affix = old
      return this
    }
  
  
    // AFFIX DATA-API
    // ==============
  
    $(window).on('load', function () {
      $('[data-spy="affix"]').each(function () {
        var $spy = $(this)
        var data = $spy.data()
  
        data.offset = data.offset || {}

        if (data.offsetBottom != null) data.offset.bottom = data.offsetBottom
        if (data.offsetTop    != null) data.offset.top    = data.offsetTop

        Plugin.call($spy, data)

      })
    })
  
  }(jQuery);