alpaca/dist/lib/bootstrap-tokenfield/docs-assets/js/scrollspy.js

Alpaca provides the easiest and fastest way to generate interactive forms for the web and mobile devices. It runs simply as HTML5 or more elaborately using Bootstrap, jQuery Mobile or jQuery UI. Alpaca uses Handlebars to process JSON schema and provide

/* ========================================================================
 * Bootstrap: scrollspy.js v3.1.1
 * http://getbootstrap.com/javascript/#scrollspy
 * ========================================================================
 * Copyright 2011-2014 Twitter, Inc.
 * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
 * ======================================================================== */


+function ($) {
  'use strict';

  // SCROLLSPY CLASS DEFINITION
  // ==========================

  function ScrollSpy(element, options) {
    var href
    var process  = $.proxy(this.process, this)

    this.$element       = $(element).is('body') ? $(window) : $(element)
    this.$body          = $('body')
    this.$scrollElement = this.$element.on('scroll.bs.scroll-spy.data-api', process)
    this.options        = $.extend({}, ScrollSpy.DEFAULTS, options)
    this.selector       = (this.options.target
      || ((href = $(element).attr('href')) && href.replace(/.*(?=#[^\s]+$)/, '')) //strip for ie7
      || '') + ' .nav li > a'
    this.offsets        = $([])
    this.targets        = $([])
    this.activeTarget   = null

    this.refresh()
    this.process()
  }

  ScrollSpy.DEFAULTS = {
    offset: 10
  }

  ScrollSpy.prototype.refresh = function () {
    var offsetMethod = this.$element[0] == window ? 'offset' : 'position'

    this.offsets = $([])
    this.targets = $([])

    var self     = this
    var $targets = this.$body
      .find(this.selector)
      .map(function () {
        var $el   = $(this)
        var href  = $el.data('target') || $el.attr('href')
        var $href = /^#./.test(href) && $(href)

        return ($href
          && $href.length
          && $href.is(':visible')
          && [[ $href[offsetMethod]().top + (!$.isWindow(self.$scrollElement.get(0)) && self.$scrollElement.scrollTop()), href ]]) || null
      })
      .sort(function (a, b) { return a[0] - b[0] })
      .each(function () {
        self.offsets.push(this[0])
        self.targets.push(this[1])
      })
  }

  ScrollSpy.prototype.process = function () {
    var scrollTop    = this.$scrollElement.scrollTop() + this.options.offset
    var scrollHeight = this.$scrollElement[0].scrollHeight || this.$body[0].scrollHeight
    var maxScroll    = scrollHeight - this.$scrollElement.height()
    var offsets      = this.offsets
    var targets      = this.targets
    var activeTarget = this.activeTarget
    var i

    if (scrollTop >= maxScroll) {
      return activeTarget != (i = targets.last()[0]) && this.activate(i)
    }

    if (activeTarget && scrollTop <= offsets[0]) {
      return activeTarget != (i = targets[0]) && this.activate(i)
    }

    for (i = offsets.length; i--;) {
      activeTarget != targets[i]
        && scrollTop >= offsets[i]
        && (!offsets[i + 1] || scrollTop <= offsets[i + 1])
        && this.activate( targets[i] )
    }
  }

  ScrollSpy.prototype.activate = function (target) {
    this.activeTarget = target

    $(this.selector)
      .parentsUntil(this.options.target, '.active')
      .removeClass('active')

    var selector = this.selector +
        '[data-target="' + target + '"],' +
        this.selector + '[href="' + target + '"]'

    var active = $(selector)
      .parents('li')
      .addClass('active')

    if (active.parent('.dropdown-menu').length) {
      active = active
        .closest('li.dropdown')
        .addClass('active')
    }

    active.trigger('activate.bs.scrollspy')
  }


  // SCROLLSPY PLUGIN DEFINITION
  // ===========================

  var old = $.fn.scrollspy

  $.fn.scrollspy = function (option) {
    return this.each(function () {
      var $this   = $(this)
      var data    = $this.data('bs.scrollspy')
      var options = typeof option == 'object' && option

      if (!data) $this.data('bs.scrollspy', (data = new ScrollSpy(this, options)))
      if (typeof option == 'string') data[option]()
    })
  }

  $.fn.scrollspy.Constructor = ScrollSpy


  // SCROLLSPY NO CONFLICT
  // =====================

  $.fn.scrollspy.noConflict = function () {
    $.fn.scrollspy = old
    return this
  }


  // SCROLLSPY DATA-API
  // ==================

  $(window).on('load', function () {
    $('[data-spy="scroll"]').each(function () {
      var $spy = $(this)
      $spy.scrollspy($spy.data())
    })
  })

}(jQuery);