D-Net

/*

 * jQuery One Page Nav Plugin

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

 *

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

 * Dual licensed under the MIT and GPL licenses.

 * Uses the same license as jQuery, see:

 * http://jquery.org/license

 *

 * @version 3.0.0

 *

 * Example usage:

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

 *   currentClass: 'current',

 *   changeHash: false,

 *   scrollSpeed: 750

 * });

 */

;(function($, window, document, undefined){

    // our plugin constructor

    var OnePageNav = function(elem, options){

        this.elem = elem;

        this.$elem = $(elem);

        this.options = options;

        this.metadata = this.$elem.data('plugin-options');

        this.$win = $(window);

        this.sections = {};

        this.didScroll = false;

        this.$doc = $(document);

        this.docHeight = this.$doc.height();

    };

    // the plugin prototype

    OnePageNav.prototype = {

        defaults: {

            navItems: 'a',

            currentClass: 'current',

            changeHash: false,

            easing: 'swing',

            filter: '',

            scrollOffset: 0,

            scrollSpeed: 750,

            scrollThreshold: 0.5,

            begin: false,

            end: false,

            scrollChange: false

        },

        init: function() {

            // Introduce defaults that can be extended either

            // globally or using an object literal.

            this.config = $.extend({}, this.defaults, this.options, this.metadata);

            this.$nav = this.$elem.find(this.config.navItems);

            //Filter any links out of the nav

            if(this.config.filter !== '') {

                this.$nav = this.$nav.filter(this.config.filter);

            }

            //Handle clicks on the nav

            this.$nav.on('click.onePageNav', $.proxy(this.handleClick, this));

            //Get the section positions

            this.getPositions();

            //Handle scroll changes

            this.bindInterval();

            //Update the positions on resize too

            this.$win.on('resize.onePageNav', $.proxy(this.getPositions, this));

            return this;

        },

        adjustNav: function(self, $parent) {

            self.$elem.find('.' + self.config.currentClass).removeClass(self.config.currentClass);

            $parent.addClass(self.config.currentClass);

        },

        bindInterval: function() {

            var self = this;

            var docHeight;

            self.$win.on('scroll.onePageNav', function() {

                self.didScroll = true;

            });

            self.t = setInterval(function() {

                docHeight = self.$doc.height();

                //If it was scrolled

                if(self.didScroll) {

                    self.didScroll = false;

                    self.scrollChange();

                }

                //If the document height changes

                if(docHeight !== self.docHeight) {

                    self.docHeight = docHeight;

                    self.getPositions();

                }

            }, 250);

        },

        getHash: function($link) {

            return $link.attr('href').split('#')[1];

        },

        getPositions: function() {

            var self = this;

            var linkHref;

            var topPos;

            var $target;

            self.$nav.each(function() {

                linkHref = self.getHash($(this));

                $target = $('#' + linkHref);

                if($target.length) {

                    topPos = $target.offset().top;

                    self.sections[linkHref] = Math.round(topPos);

                }

            });

        },

        getSection: function(windowPos) {

            var returnValue = null;

            var windowHeight = Math.round(this.$win.height() * this.config.scrollThreshold);

            // Sort Sections by Position

            this.sections = this.sortSectionsByPosition(this.sections);

            for(var section in this.sections) {

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

                    returnValue = section;

                }

            }

            return returnValue;

        },

        /**

         * Sort Sections by its position value

         * based on http://am.aurlien.net/post/1221493460/sorting-javascript-objects

         * @param  {Object} obj		Object to sort

         * @return {Object}         sorted Object

         */

        sortSectionsByPosition: function (obj) {

            var tempArray = [];

            var tempObj = {};

            // Transform Object in Array

            for (var key in obj) {

                if (obj.hasOwnProperty(key)) {

                    tempArray.push(key);

                }

            }

            tempArray.sort(function(a,b) {

                var x = obj[a];

                var y = obj[b];

                return ((x < y) ? -1 : ((x > y) ? 1 : 0));

            });

            // Transform sorted tempArray back into Object

            for (var i=0; i<tempArray.length; i++) {

                tempObj[tempArray[i]] = obj[tempArray[i]];

            }

            return tempObj;

        },

        handleClick: function(e) {

            var self = this;

            var $link = $(e.currentTarget);

            var $parent = $link.parent();

            var newLoc = '#' + self.getHash($link);

            if(!$parent.hasClass(self.config.currentClass)) {

                //Start callback

                if(self.config.begin) {

                    self.config.begin();

                }

                //Change the highlighted nav item

                self.adjustNav(self, $parent);

                //Removing the auto-adjust on scroll

                self.unbindInterval();

                //Scroll to the correct position

                self.scrollTo(newLoc, function() {

                    //Do we need to change the hash?

                    if(self.config.changeHash) {

                        window.location.hash = newLoc;

                    }

                    //Add the auto-adjust on scroll back in

                    self.bindInterval();

                    //End callback

                    if(self.config.end) {

                        self.config.end();

                    }

                });

            }

            e.preventDefault();

        },

        scrollChange: function() {

            var windowTop = this.$win.scrollTop();

            var position = this.getSection(windowTop);

            var $parent;

            //If the position is set

            if(position !== null) {

                $parent = this.$elem.find('a[href$="#' + position + '"]').parent();

                //If it's not already the current section

                if(!$parent.hasClass(this.config.currentClass)) {

                    //Change the highlighted nav item

                    this.adjustNav(this, $parent);

                    //If there is a scrollChange callback

                    if(this.config.scrollChange) {

                        this.config.scrollChange($parent);

                    }

                }

            }

        },

        scrollTo: function(target, callback) {

            var offset = $(target).offset().top;

            $('html, body').animate({

                scrollTop: offset + this.config.scrollOffset

            }, this.config.scrollSpeed, this.config.easing, callback);

        },

        unbindInterval: function() {

            clearInterval(this.t);

            this.$win.unbind('scroll.onePageNav');

        }

    };

    OnePageNav.defaults = OnePageNav.prototype.defaults;

    $.fn.onePageNav = function(options) {

        return this.each(function() {

            new OnePageNav(this, options).init();

        });

    };

})( jQuery, window , document );