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

* bootstrap-scrollspy.js v2.0.2
* http://twitter.github.com/bootstrap/javascript.html#scrollspy
* =============================================================
* Copyright 2012 Twitter, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
* ============================================================== */

!function ( $ ) {

 "use strict"

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

 function ScrollSpy( element, options) {
   var process = $.proxy(this.process, this)
     , $element = $(element).is('body') ? $(window) : $(element)
     , href
   this.options = $.extend({}, $.fn.scrollspy.defaults, options)
   this.$scrollElement = $element.on('scroll.scroll.data-api', process)
   this.selector = (this.options.target
     || ((href = $(element).attr('href')) && href.replace(/.*(?=#[^\s]+$)/, '')) //strip for ie7
     || '') + ' .nav li > a'
   this.$body = $('body').on('click.scroll.data-api', this.selector, process)
   this.refresh()
   this.process()
 }

 ScrollSpy.prototype = {

     constructor: ScrollSpy

   , refresh: function () {
       this.targets = this.$body
         .find(this.selector)
         .map(function () {
           var href = $(this).attr('href')
           return /^#\w/.test(href) && $(href).length ? href : null
         })

       this.offsets = $.map(this.targets, function (id) {
         return $(id).position().top
       })
     }

   , process: function () {
       var scrollTop = this.$scrollElement.scrollTop() + this.options.offset
         , offsets = this.offsets
         , targets = this.targets
         , activeTarget = this.activeTarget
         , i

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

   , activate: function (target) {
       var active

       this.activeTarget = target

       this.$body
         .find(this.selector).parent('.active')
         .removeClass('active')

       active = this.$body
         .find(this.selector + '[href="' + target + '"]')
         .parent('li')
         .addClass('active')

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

 }

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

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

 $.fn.scrollspy.Constructor = ScrollSpy

 $.fn.scrollspy.defaults = {
   offset: 10
 }

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

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

}( window.jQuery );