https://berestov.org/wp-content/themes/graphy/js/navigation.js?ver=20160525

1/**
2 * navigation.js
3 *
4 * Handles toggling the navigation menu for small screens and enables tab
5 * support for dropdown menus.
6 */
7( function() {
8	"use strict";
9	
10	var container, button, menu, links, subMenus;
11
12	container = document.getElementById( 'site-navigation' );
13	if ( ! container ) {
14		return;
15	}
16
17	button = container.getElementsByTagName( 'button' )[0];
18	if ( 'undefined' === typeof button ) {
19		return;
20	}
21
22	menu = container.getElementsByTagName( 'ul' )[0];
23
24	if ( -1 === menu.className.indexOf( 'nav-menu' ) ) {
25		menu.className += ' nav-menu';
26	}
27
28	function setARIA() {
29		if ( 783 > window.innerWidth ) {
30			button.setAttribute( 'aria-controls', 'primary-menu' );
31			button.setAttribute( 'aria-expanded', 'false' );
32			menu.setAttribute( 'aria-expanded', 'false' );
33		} else {
34			button.removeAttribute( 'aria-controls' );
35			button.removeAttribute( 'aria-expanded' );
36			menu.removeAttribute( 'aria-expanded' );
37		}
38	}
39
40	button.onclick = function() {
41		if ( -1 !== container.className.indexOf( 'toggled' ) ) {
42			container.className = container.className.replace( ' toggled', '' );
43			button.setAttribute( 'aria-expanded', 'false' );
44			menu.setAttribute( 'aria-expanded', 'false' );
45		} else {
46			container.className += ' toggled';
47			button.setAttribute( 'aria-expanded', 'true' );
48			menu.setAttribute( 'aria-expanded', 'true' );
49		}
50	};
51
52	// Get all the link elements within the menu.
53	links    = menu.getElementsByTagName( 'a' );
54	subMenus = menu.getElementsByTagName( 'ul' );
55
56	// Set ARIA attributes properly.
57	window.addEventListener( 'load', setARIA, false );
58	window.addEventListener( 'resize', setARIA, true );
59
60	// Set menu items with submenus to aria-haspopup="true".
61	for ( var i = 0, len = subMenus.length; i < len; i++ ) {
62		subMenus[i].parentNode.setAttribute( 'aria-haspopup', 'true' );
63	}
64
65	// Each time a menu link is focused or blurred, toggle focus.
66	for ( i = 0, len = links.length; i < len; i++ ) {
67		links[i].addEventListener( 'focus', toggleFocus, true );
68		links[i].addEventListener( 'blur', toggleFocus, true );
69	}
70
71	/**
72	 * Sets or removes .focus class on an element.
73	 */
74	function toggleFocus() {
75		var self = this;
76
77		// Move up through the ancestors of the current link until we hit .nav-menu.
78		while ( -1 === self.className.indexOf( 'nav-menu' ) ) {
79
80			// On li elements toggle the class .focus.
81			if ( 'li' === self.tagName.toLowerCase() ) {
82				if ( -1 !== self.className.indexOf( 'focus' ) ) {
83					self.className = self.className.replace( ' focus', '' );
84				} else {
85					self.className += ' focus';
86				}
87			}
88
89			self = self.parentElement;
90		}
91	}
92} )();