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Bootstrap/js/bootstrap-scrollspy.js
2011-09-10 22:24:31 -07:00

88 lines
2.5 KiB
JavaScript

/* =============================================================
* bootstrap-scrollspy.js
* http://twitter.github.com/bootstrap/javascript.html#scrollspy
* =============================================================
* Copyright 2011 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 ( $ ) {
var $window = $(window)
function ScrollSpy( topbar ) {
var processScroll = $.proxy(this.processScroll, this)
this.$topbar = $(topbar)
this.setup()
this.$topbar
.delegate('li > a', 'click', processScroll)
.bind('topbar:refresh', $.proxy(this.setup, this))
$window.scroll(processScroll)
this.processScroll()
}
ScrollSpy.prototype = {
setup: function () {
this.targets = this.$topbar.find('li > a').map(function () {
var href = $(this).attr('href')
return /^#\w/.test(href) && $(href).length ? href : null
})
this.offsets = $.map(this.targets, function (id) {
return $(id).offset().top
})
}
, processScroll: function () {
var scrollTop = $window.scrollTop() + 10
, offsets = this.offsets
, targets = this.targets
, activeTarget = this.activeTarget
, i
for (i = offsets.length; i--;) {
activeTarget != targets[i]
&& scrollTop >= offsets[i]
&& (!offsets[i + 1] || scrollTop <= offsets[i + 1])
&& this.activateButton( targets[i] )
}
}
, activateButton: function (target) {
this.activeTarget = target
this.$topbar
.find('.active')
.removeClass('active')
this.$topbar
.find('a[href=' + target + ']')
.parent('li')
.addClass('active')
}
}
/* SCROLLSPY PLUGIN DEFINITION
* =========================== */
$.fn.scrollSpy = function() {
return this.each(function () {
new ScrollSpy(this)
})
}
}( jQuery || ender )