/* * 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 2.2.0 * * 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.$nav = this.$elem.find('a');		this.$win = $(window);		this.sections = {};		this.didScroll = false;		this.$doc = $(document);		this.docHeight = this.$doc.height();	};
	// the plugin prototype	OnePageNav.prototype = {		defaults: {			currentClass: 'current',			changeHash: false,			easing: 'swing',			filter: '',			scrollSpeed: 750,			scrollOffset: 0,			scrollThreshold: 0.5,			begin: false,			end: false,			scrollChange: false		},
		init: function() {			var self = this;						// Introduce defaults that can be extended either			// globally or using an object literal.			self.config = $.extend({}, self.defaults, self.options, self.metadata);						//Filter any links out of the nav			if(self.config.filter !== '') {				self.$nav = self.$nav.filter(self.config.filter);			}						//Handle clicks on the nav			self.$nav.on('click.onePageNav', $.proxy(self.handleClick, self));
			//Get the section positions			self.getPositions();						//Handle scroll changes			self.bindInterval();						//Update the positions on resize too			self.$win.on('resize.onePageNav', $.proxy(self.getPositions, self));
			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 = $target.offset().top;					self.sections[linkHref] = Math.round(topPos) - self.config.scrollOffset;				}			});		},				getSection: function(windowPos) {			var returnValue = null;			var windowHeight = Math.round(this.$win.height() * this.config.scrollThreshold);
			for(var section in this.sections) {				if((this.sections[section] - windowHeight) < windowPos) {					returnValue = section;				}			}						return returnValue;		},				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				$.scrollTo(newLoc, self.config.scrollSpeed, {					axis: 'y',					easing: self.config.easing,					offset: {						top: -self.config.scrollOffset					},					onAfter: function() {						//Do we need to change the hash?						if(self.config.changeHash) {							window.location.hash = newLoc;						}												//Add the auto-adjust on scroll back in						self.bindInterval();												//End callback						if(self.config.end) {							self.config.end();						}					}				});			}
			e.preventDefault();		},				scrollChange: function() {			var windowTop = this.$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);					}				}			}		},				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 );