https://www.psychiatrie-und-ethik.de/wpgepde/wp-content/themes/twentytwelve/js/navigation.js?ver=20141205

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.twentytwelve blur.twentytwelve', function() {
41		$( this ).parents( '.menu-item, .page_item' ).toggleClass( 'focus' );
42	} );
43
44  if ( 'ontouchstart' in window ) {
45    $('body').on( 'touchstart.twentytwelve',  '.menu-item-has-children > a, .page_item_has_children > a', 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 );