1 /*

     2  * jQuery One Page Nav Plugin

     3  * http://github.com/davist11/jQuery-One-Page-Nav

     4  *

     5  * Copyright (c) 2010 Trevor Davis (http://trevordavis.net)

     6  * Dual licensed under the MIT and GPL licenses.

     7  * Uses the same license as jQuery, see:

     8  * http://jquery.org/license

     9  *

    10  * @version 0.7

    11  *

    12  * Example usage:

    13  * $('#nav').onePageNav({

    14  *   currentClass: 'current',

    15  *   changeHash: false,

    16  *   scrollSpeed: 750

    17  * });

    18  */

    19 ;(function($) {

    20   $.fn.onePageNav = function(options) {

    21     var opts = $.extend({}, $.fn.onePageNav.defaults, options),

    22         onePageNav = {};

    23     

    24     onePageNav.sections = {};

    25     

    26     onePageNav.bindNav = function($el, $this, o) {

    27       var $par = $el.parent(),

    28           newLoc = $el.attr('href'),

    29           $win = $(window);

    30 

    31       if(!$par.hasClass(o.currentClass)) {

    32         if(o.begin) {

    33           o.begin();

    34         }

    35         onePageNav.adjustNav($this, $par, o.currentClass);

    36         $win.unbind('.onePageNav');

    37         $.scrollTo(newLoc, o.scrollSpeed, {

    38           offset: {

    39             top: -o.scrollOffset

    40           },

    41           onAfter: function() {

    42             if(o.changeHash) {

    43               window.location.hash = newLoc;

    44             }

    45             $win.bind('scroll.onePageNav', function() {

    46               onePageNav.scrollChange($this, o);

    47             });

    48             if(o.end) {

    49               o.end();

    50             }

    51           }

    52         });

    53       }

    54     };

    55     

    56     onePageNav.adjustNav = function($this, $el, curClass) {

    57       $this.find('.'+curClass).removeClass(curClass);

    58       $el.addClass(curClass);

    59     };

    60     

    61     onePageNav.getPositions = function($this, o) {

    62       $this.find('a').each(function() {

    63         var linkHref = $(this).attr('href'),

    64             divPos = $(linkHref).offset(),

    65             topPos = divPos.top;

    66             

    67         onePageNav.sections[linkHref.substr(1)] = Math.round(topPos) - o.scrollOffset;

    68       });

    69     };

    70     

    71     onePageNav.getSection = function(windowPos) {

    72       var returnValue = '',

    73           windowHeight = Math.round($(window).height() / 2);

    74       

    75       for(var section in onePageNav.sections) {

    76         if((onePageNav.sections[section] - windowHeight) < windowPos) {

    77           returnValue = section;

    78         }

    79       }

    80       return returnValue;

    81     };

    82     

    83     onePageNav.scrollChange = function($this, o) {

    84       onePageNav.getPositions($this, o);

    85       

    86       var windowTop = $(window).scrollTop(),

    87           position = onePageNav.getSection(windowTop);

    88           

    89       if(position !== '') {

    90         onePageNav.adjustNav($this,$this.find('a[href=#'+position+']').parent(), o.currentClass);

    91       }

    92     };

    93     

    94     onePageNav.init = function($this, o) {

    95       var didScroll = false;

    96       

    97       $this.find('a').bind('click', function(e) {

    98         onePageNav.bindNav($(this), $this, o);

    99         e.preventDefault();

   100       });

   101     

   102       onePageNav.getPositions($this, o);

   103     

   104       $(window).bind('scroll.onePageNav', function() {

   105         didScroll = true;

   106       });

   107 

   108       setInterval(function() {

   109         if(didScroll) {

   110           didScroll = false;

   111           onePageNav.scrollChange($this, o);

   112         }

   113       }, 250);

   114     };

   115     

   116     return this.each(function() {

   117       var $this = $(this),

   118           o = $.meta ? $.extend({}, opts, $this.data()) : opts;

   119       

   120       onePageNav.init($this, o);

   121     

   122     });

   123   };

   124 

   125   // default options

   126   $.fn.onePageNav.defaults = {

   127     currentClass: 'current',

   128     changeHash: false,

   129     scrollSpeed: 0,

   130     scrollOffset: 0,

   131     begin: false,

   132     end: false

   133   };

   134 

   135 })(jQuery);