https://lirh.it/themes/arturu/node_modules/bootstrap-sass/assets/javascripts/bootstrap/affix.js?tli391

1/* ========================================================================
2 * Bootstrap: affix.js v3.4.1
3 * https://getbootstrap.com/docs/3.4/javascript/#affix
4 * ========================================================================
5 * Copyright 2011-2019 Twitter, Inc.
6 * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
7 * ======================================================================== */
8
9
10+function ($) {
11  'use strict';
12
13  // AFFIX CLASS DEFINITION
14  // ======================
15
16  var Affix = function (element, options) {
17    this.options = $.extend({}, Affix.DEFAULTS, options)
18
19    var target = this.options.target === Affix.DEFAULTS.target ? $(this.options.target) : $(document).find(this.options.target)
20
21    this.$target = target
22      .on('scroll.bs.affix.data-api', $.proxy(this.checkPosition, this))
23      .on('click.bs.affix.data-api',  $.proxy(this.checkPositionWithEventLoop, this))
24
25    this.$element     = $(element)
26    this.affixed      = null
27    this.unpin        = null
28    this.pinnedOffset = null
29
30    this.checkPosition()
31  }
32
33  Affix.VERSION  = '3.4.1'
34
35  Affix.RESET    = 'affix affix-top affix-bottom'
36
37  Affix.DEFAULTS = {
38    offset: 0,
39    target: window
40  }
41
42  Affix.prototype.getState = function (scrollHeight, height, offsetTop, offsetBottom) {
43    var scrollTop    = this.$target.scrollTop()
44    var position     = this.$element.offset()
45    var targetHeight = this.$target.height()
46
47    if (offsetTop != null && this.affixed == 'top') return scrollTop < offsetTop ? 'top' : false
48
49    if (this.affixed == 'bottom') {
50      if (offsetTop != null) return (scrollTop + this.unpin <= position.top) ? false : 'bottom'
51      return (scrollTop + targetHeight <= scrollHeight - offsetBottom) ? false : 'bottom'
52    }
53
54    var initializing   = this.affixed == null
55    var colliderTop    = initializing ? scrollTop : position.top
56    var colliderHeight = initializing ? targetHeight : height
57
58    if (offsetTop != null && scrollTop <= offsetTop) return 'top'
59    if (offsetBottom != null && (colliderTop + colliderHeight >= scrollHeight - offsetBottom)) return 'bottom'
60
61    return false
62  }
63
64  Affix.prototype.getPinnedOffset = function () {
65    if (this.pinnedOffset) return this.pinnedOffset
66    this.$element.removeClass(Affix.RESET).addClass('affix')
67    var scrollTop = this.$target.scrollTop()
68    var position  = this.$element.offset()
69    return (this.pinnedOffset = position.top - scrollTop)
70  }
71
72  Affix.prototype.checkPositionWithEventLoop = function () {
73    setTimeout($.proxy(this.checkPosition, this), 1)
74  }
75
76  Affix.prototype.checkPosition = function () {
77    if (!this.$element.is(':visible')) return
78
79    var height       = this.$element.height()
80    var offset       = this.options.offset
81    var offsetTop    = offset.top
82    var offsetBottom = offset.bottom
83    var scrollHeight = Math.max($(document).height(), $(document.body).height())
84
85    if (typeof offset != 'object')         offsetBottom = offsetTop = offset
86    if (typeof offsetTop == 'function')    offsetTop    = offset.top(this.$element)
87    if (typeof offsetBottom == 'function') offsetBottom = offset.bottom(this.$element)
88
89    var affix = this.getState(scrollHeight, height, offsetTop, offsetBottom)
90
91    if (this.affixed != affix) {
92      if (this.unpin != null) this.$element.css('top', '')
93
94      var affixType = 'affix' + (affix ? '-' + affix : '')
95      var e         = $.Event(affixType + '.bs.affix')
96
97      this.$element.trigger(e)
98
99      if (e.isDefaultPrevented()) return
100
101      this.affixed = affix
102      this.unpin = affix == 'bottom' ? this.getPinnedOffset() : null
103
104      this.$element
105        .removeClass(Affix.RESET)
106        .addClass(affixType)
107        .trigger(affixType.replace('affix', 'affixed') + '.bs.affix')
108    }
109
110    if (affix == 'bottom') {
111      this.$element.offset({
112        top: scrollHeight - height - offsetBottom
113      })
114    }
115  }
116
117
118  // AFFIX PLUGIN DEFINITION
119  // =======================
120
121  function Plugin(option) {
122    return this.each(function () {
123      var $this   = $(this)
124      var data    = $this.data('bs.affix')
125      var options = typeof option == 'object' && option
126
127      if (!data) $this.data('bs.affix', (data = new Affix(this, options)))
128      if (typeof option == 'string') data[option]()
129    })
130  }
131
132  var old = $.fn.affix
133
134  $.fn.affix             = Plugin
135  $.fn.affix.Constructor = Affix
136
137
138  // AFFIX NO CONFLICT
139  // =================
140
141  $.fn.affix.noConflict = function () {
142    $.fn.affix = old
143    return this
144  }
145
146
147  // AFFIX DATA-API
148  // ==============
149
150  $(window).on('load', function () {
151    $('[data-spy="affix"]').each(function () {
152      var $spy = $(this)
153      var data = $spy.data()
154
155      data.offset = data.offset || {}
156
157      if (data.offsetBottom != null) data.offset.bottom = data.offsetBottom
158      if (data.offsetTop    != null) data.offset.top    = data.offsetTop
159
160      Plugin.call($spy, data)
161    })
162  })
163
164}(jQuery);