bootstrap-scrollspy.js

/* =============================================================
 * bootstrap-scrollspy.js v2.0.4
 * 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"; // jshint ;_;


  /* SCROLLSPY CLASS DEFINITION
   * ========================== */

  function ScrollSpy( element, options) {
    var process = $.proxy(this.process, this)
      , $element = $(element).is('body') ? $(window) : $(element)
      , href
    this.options = $.extend({}, $.fn.scrollspy.defaults, options)
    this.$scrollElement = $element.on('scroll.scroll.data-api', process)
    this.selector = (this.options.target
      || ((href = $(element).attr('href')) && href.replace(/.*(?=#[^\s]+$)/, '')) //strip for ie7
      || '') + ' .nav li > a'
    this.$body = $('body')
    this.refresh()
    this.process()
  }

  ScrollSpy.prototype = {

      constructor: ScrollSpy

    , refresh: function () {
        var self = this
          , $targets

        this.offsets = $([])
        this.targets = $([])

        $targets = this.$body
          .find(this.selector)
          .map(function () {
            var $el = $(this)
              , href = $el.data('target') || $el.attr('href')
              , $href = /^#\w/.test(href) && $(href)
            return ( $href
              && $href.length
              && [[ $href.position().top, href ]] ) || null
          })
          .sort(function (a, b) { return a[0] - b[0] })
          .each(function () {
            self.offsets.push(this[0])
            self.targets.push(this[1])
          })
      }