/**
* 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
*/
// Utility
if (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);