balmet.com

pagenav.js (5363B)

---

 /*
  * 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: '',
 			scrollSpeed: 1500,
 			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);
 
 			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
 				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-70;
 
 			$('html, body').animate({
 				scrollTop: offset
 			}, 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 );