1/* =============================================================
2 * bootstrap-scrollspy.js v2.3.1
3 * http://twitter.github.com/bootstrap/javascript.html#scrollspy
4 * =============================================================
5 * Copyright 2012 Twitter, Inc.
6 *
7 * Licensed under the Apache License, Version 2.0 (the "License");
8 * you may not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 * ============================================================== */
19
20
21!function ($) {
22
23  "use strict"; // jshint ;_;
24
25
26 /* SCROLLSPY CLASS DEFINITION
27  * ========================== */
28
29  function ScrollSpy(element, options) {
30    var process = $.proxy(this.process, this)
31      , $element = $(element).is('body') ? $(window) : $(element)
32      , href
33    this.options = $.extend({}, $.fn.scrollspy.defaults, options)
34    this.$scrollElement = $element.on('scroll.scroll-spy.data-api', process)
35    this.selector = (this.options.target
36      || ((href = $(element).attr('href')) && href.replace(/.*(?=#[^\s]+$)/, '')) //strip for ie7
37      || '') + ' .nav li > a'
38    this.$body = $('body')
39    this.refresh()
40    this.process()
41  }
42
43  ScrollSpy.prototype = {
44
45      constructor: ScrollSpy
46
47    , refresh: function () {
48        var self = this
49          , $targets
50
51        this.offsets = $([])
52        this.targets = $([])
53
54        $targets = this.$body
55          .find(this.selector)
56          .map(function () {
57            var $el = $(this)
58              , href = $el.data('target') || $el.attr('href')
59              , $href = /^#\w/.test(href) && $(href)
60            return ( $href
61              && $href.length
62              && [[ $href.position().top + (!$.isWindow(self.$scrollElement.get(0)) && self.$scrollElement.scrollTop()), href ]] ) || null
63          })
64          .sort(function (a, b) { return a[0] - b[0] })
65          .each(function () {
66            self.offsets.push(this[0])
67            self.targets.push(this[1])
68          })
69      }
70
71    , process: function () {
72        var scrollTop = this.$scrollElement.scrollTop() + this.options.offset
73          , scrollHeight = this.$scrollElement[0].scrollHeight || this.$body[0].scrollHeight
74          , maxScroll = scrollHeight - this.$scrollElement.height()
75          , offsets = this.offsets
76          , targets = this.targets
77          , activeTarget = this.activeTarget
78          , i
79
80        if (scrollTop >= maxScroll) {
81          return activeTarget != (i = targets.last()[0])
82            && this.activate ( i )
83        }
84
85        for (i = offsets.length; i--;) {
86          activeTarget != targets[i]
87            && scrollTop >= offsets[i]
88            && (!offsets[i + 1] || scrollTop <= offsets[i + 1])
89            && this.activate( targets[i] )
90        }
91      }
92
93    , activate: function (target) {
94        var active
95          , selector
96
97        this.activeTarget = target
98
99        $(this.selector)
100          .parent('.active')
101          .removeClass('active')
102
103        selector = this.selector
104          + '[data-target="' + target + '"],'
105          + this.selector + '[href="' + target + '"]'
106
107        active = $(selector)
108          .parent('li')
109          .addClass('active')
110
111        if (active.parent('.dropdown-menu').length)  {
112          active = active.closest('li.dropdown').addClass('active')
113        }
114
115        active.trigger('activate')
116      }
117
118  }
119
120
121 /* SCROLLSPY PLUGIN DEFINITION
122  * =========================== */
123
124  var old = $.fn.scrollspy
125
126  $.fn.scrollspy = function (option) {
127    return this.each(function () {
128      var $this = $(this)
129        , data = $this.data('scrollspy')
130        , options = typeof option == 'object' && option
131      if (!data) $this.data('scrollspy', (data = new ScrollSpy(this, options)))
132      if (typeof option == 'string') data[option]()
133    })
134  }
135
136  $.fn.scrollspy.Constructor = ScrollSpy
137
138  $.fn.scrollspy.defaults = {
139    offset: 10
140  }
141
142
143 /* SCROLLSPY NO CONFLICT
144  * ===================== */
145
146  $.fn.scrollspy.noConflict = function () {
147    $.fn.scrollspy = old
148    return this
149  }
150
151
152 /* SCROLLSPY DATA-API
153  * ================== */
154
155  $(window).on('load', function () {
156    $('[data-spy="scroll"]').each(function () {
157      var $spy = $(this)
158      $spy.scrollspy($spy.data())
159    })
160  })
161
162}(window.jQuery);