/media/com_bootstrap/js/bootstrap-scrollspy.js

  1/* =============================================================
  2 * bootstrap-scrollspy.js v2.1.1
  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              && [[ $href.position().top, href ]] ) || null
 63          })
 64          .sort(function (a, b) { return a[0] - b[0] })
 65          .each(function () {
 66            self.offsets.push(this[0])
 67            self.targets.push(this[1])
 68          })
 69      }
 70
 71    , process: function () {
 72        var scrollTop = this.$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  $.fn.scrollspy = function (option) {
125    return this.each(function () {
126      var $this = $(this)
127        , data = $this.data('scrollspy')
128        , options = typeof option == 'object' && option
129      if (!data) $this.data('scrollspy', (data = new ScrollSpy(this, options)))
130      if (typeof option == 'string') data[option]()
131    })
132  }
133
134  $.fn.scrollspy.Constructor = ScrollSpy
135
136  $.fn.scrollspy.defaults = {
137    offset: 10
138  }
139
140
141 /* SCROLLSPY DATA-API
142  * ================== */
143
144  $(window).on('load', function () {
145    $('[data-spy="scroll"]').each(function () {
146      var $spy = $(this)
147      $spy.scrollspy($spy.data())
148    })
149  })
150
151}(window.jQuery);