https://vincellstudios.com/blog/wp-content/themes/bloggers-lite/js/bloggers-lite-navigation.js?ver=20140711

1/**
2 * Handles toggling the navigation menu for small screens and
3 * accessibility for submenu items.
4 */
5(function () {
6    var nav = document.getElementById('site-navigation'), button, menu;
7    if (!nav) {
8        return;
9    }
10
11    button = nav.getElementsByTagName('button')[0];
12    menu = nav.getElementsByTagName('ul')[0];
13    if (!button) {
14        return;
15    }
16
17    // Hide button if menu is missing or empty.
18    if (!menu || !menu.childNodes.length) {
19        button.style.display = 'none';
20        return;
21    }
22
23    button.onclick = function () {
24        if (-1 === menu.className.indexOf('nav-menu')) {
25            menu.className = 'nav-menu';
26        }
27
28        if (-1 !== button.className.indexOf('toggled-on')) {
29            button.className = button.className.replace(' toggled-on', '');
30            menu.className = menu.className.replace(' toggled-on', '');
31        } else {
32            button.className += ' toggled-on';
33            menu.className += ' toggled-on';
34        }
35    };
36})();
37
38// Better focus for hidden submenu items for accessibility.
39(function ($) {
40    $('.main-navigation').find('a').on('focus.bloggers-lite blur.bloggers-lite', function () {
41        $(this).parents('.menu-item, .page_item').toggleClass('focus');
42    });
43
44    if ('ontouchstart' in window) {
45        $('.menu-item-has-children > a').on('touchstart.bloggers-lite', function (e) {
46            var el = $(this).parent('li');
47
48            if (!el.hasClass('focus')) {
49                e.preventDefault();
50                el.toggleClass('focus');
51                el.siblings('.focus').removeClass('focus');
52            }
53        });
54    }
55})(jQuery);