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Bootstrap/js/bootstrap-scrollspy.js
2012-01-26 15:00:59 -08:00

125 lines
3.5 KiB
JavaScript

/* =============================================================
* bootstrap-scrollspy.js v2.0.0
* 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)
this.options = $.extend({}, $.fn.scrollspy.defaults, options)
this.$scrollElement = $element.on('scroll.scroll.data-api', process)
this.selector = (this.options.target
|| $(element).attr('href')
|| '') + ' .nav li > a'
this.$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 )