/** * Single Page Nav Plugin * Copyright (c) 2014 Chris Wojcik <hello@chriswojcik.net> * Dual licensed under MIT and GPL. * @author Chris Wojcik * @version 1.2.0 */
// Utilityif (typeof Object.create !== 'function') {    Object.create = function(obj) {        function F() {}        F.prototype = obj;        return new F();    };}
(function($, window, document, undefined) {    "use strict";        var SinglePageNav = {                init: function(options, container) {                        this.options = $.extend({}, $.fn.singlePageNav.defaults, options);                        this.container = container;                        this.$container = $(container);            this.$links = this.$container.find('a');
            if (this.options.filter !== '') {                this.$links = this.$links.filter(this.options.filter);            }
            this.$window = $(window);            this.$htmlbody = $('html, body');                        this.$links.on('click.singlePageNav', $.proxy(this.handleClick, this));
            this.didScroll = false;            this.checkPosition();            this.setTimer();        },
        handleClick: function(e) {            var self  = this,                link  = e.currentTarget,                $elem = $(link.hash);
            e.preventDefault();             
            if ($elem.length) { // Make sure the target elem exists
                // Prevent active link from cycling during the scroll                self.clearTimer();
                // Before scrolling starts                if (typeof self.options.beforeStart === 'function') {                    self.options.beforeStart();                }
                self.setActiveLink(link.hash);                                self.scrollTo($elem, function() { 
                    if (self.options.updateHash && history.pushState) {                        history.pushState(null,null, link.hash);                    }
                    self.setTimer();
                    // After scrolling ends                    if (typeof self.options.onComplete === 'function') {                        self.options.onComplete();                    }                });                                        }             },                scrollTo: function($elem, callback) {            var self = this;            var target = self.getCoords($elem).top;            var called = false;
            self.$htmlbody.stop().animate(                {scrollTop: target},                 {                     duration: self.options.speed,                    easing: self.options.easing,                     complete: function() {                        if (typeof callback === 'function' && !called) {                            callback();                        }                        called = true;                    }                }            );        },                setTimer: function() {            var self = this;                        self.$window.on('scroll.singlePageNav', function() {                self.didScroll = true;            });                        self.timer = setInterval(function() {                if (self.didScroll) {                    self.didScroll = false;                    self.checkPosition();                }            }, 250);        },                        clearTimer: function() {            clearInterval(this.timer);            this.$window.off('scroll.singlePageNav');            this.didScroll = false;        },                // Check the scroll position and set the active section        checkPosition: function() {            var scrollPos = this.$window.scrollTop();            var currentSection = this.getCurrentSection(scrollPos);            if(currentSection!==null) {                this.setActiveLink(currentSection);            }        },                        getCoords: function($elem) {            return {                top: Math.round($elem.offset().top) - this.options.offset            };        },                setActiveLink: function(href) {            var $activeLink = this.$container.find("a[href$='" + href + "']");                                        if (!$activeLink.hasClass(this.options.currentClass)) {                this.$links.removeClass(this.options.currentClass);                $activeLink.addClass(this.options.currentClass);            }        },                        getCurrentSection: function(scrollPos) {            var i, hash, coords, section;                        for (i = 0; i < this.$links.length; i++) {                hash = this.$links[i].hash;                                if ($(hash).length) {                    coords = this.getCoords($(hash));                                        if (scrollPos >= coords.top - this.options.threshold) {                        section = hash;                    }                }            }                        // The current section or the first link if it is found            return section || ((this.$links.length===0) ? (null) : (this.$links[0].hash));        }    };        $.fn.singlePageNav = function(options) {        return this.each(function() {            var singlePageNav = Object.create(SinglePageNav);            singlePageNav.init(options, this);        });    };        $.fn.singlePageNav.defaults = {        offset: 0,        threshold: 120,        speed: 400,        currentClass: 'current',        easing: 'swing',        updateHash: false,        filter: '',        onComplete: false,        beforeStart: false    };    })(jQuery, window, document);