Affix.prototype.checkPosition = function()

in content/javascript/affix.js [38:65]


  Affix.prototype.checkPosition = function () {
    if (!this.$element.is(':visible')) return

    var scrollHeight = $(document).height()
      , scrollTop = this.$window.scrollTop()
      , position = this.$element.offset()
      , offset = this.options.offset
      , offsetBottom = offset.bottom
      , offsetTop = offset.top
      , reset = 'affix affix-top affix-bottom'
      , affix

    if (typeof offset != 'object') offsetBottom = offsetTop = offset
    if (typeof offsetTop == 'function') offsetTop = offset.top()
    if (typeof offsetBottom == 'function') offsetBottom = offset.bottom()

    affix = this.unpin != null && (scrollTop + this.unpin <= position.top) ?
      false    : offsetBottom != null && (position.top + this.$element.height() >= scrollHeight - offsetBottom) ?
      'bottom' : offsetTop != null && scrollTop <= offsetTop ?
      'top'    : false

    if (this.affixed === affix) return

    this.affixed = affix
    this.unpin = affix == 'bottom' ? position.top - scrollTop : null

    this.$element.removeClass(reset).addClass('affix' + (affix ? '-' + affix : ''))
  }