https://gutscheine.cafe-wien.at/templates/qwk/t1/javascript/header-mobile.js

1var disableScroll = false;
2
3$("#navigation-toggle-responsive").click(function(){
4    var $this = $(this),
5        $headerNavigation = $(".inc-page-navigation"),
6        $headerNavigationToggle = $("#navigation-toggle-responsive");
7
8    $headerNavigation.toggleClass("open");
9    $headerNavigationToggle.toggleClass("open");
10
11    if ($headerNavigation.hasClass("open")) {
12        disableScrolling();
13        $headerNavigationToggle.attr("aria-expanded", "true");
14        $headerNavigationToggle.find('.navigation-toggle-responsive-open').hide();
15        $headerNavigationToggle.find('.navigation-toggle-responsive-close').show();
16    } else {
17        enableScrolling();
18        $headerNavigationToggle.attr("aria-expanded", "false");
19        $headerNavigationToggle.find('.navigation-toggle-responsive-open').show();
20        $headerNavigationToggle.find('.navigation-toggle-responsive-close').hide();
21    }
22});
23
24function disableScrolling() {
25    disableScroll = true;
26
27    // lock scroll position, but retain settings for later
28    var scrollPosition = [
29        self.pageXOffset || document.documentElement.scrollLeft || document.body.scrollLeft,
30        self.pageYOffset || document.documentElement.scrollTop  || document.body.scrollTop
31    ];
32
33    // var scrollPosition = [
34    //     self.pageXOffset || document.documentElement.scrollLeft || document.body.scrollLeft,
35    //     self.pageYOffset || document.documentElement.scrollTop  || document.body.scrollTop
36    // ];
37
38    var html = jQuery('html'); // it would make more sense to apply this to body, but IE7 won't have that
39    html.data('scroll-position', scrollPosition);
40    html.data('previous-overflow', html.css('overflow'));
41    html.css('overflow', 'hidden');
42    window.scrollTo(scrollPosition[0], scrollPosition[1]);
43}
44
45function enableScrolling() {
46    disableScroll = false;
47
48    // lock scroll position, but retain settings for later
49    var scrollPosition = [
50        self.pageXOffset || document.documentElement.scrollLeft || document.body.scrollLeft,
51        self.pageYOffset || document.documentElement.scrollTop  || document.body.scrollTop
52    ];
53
54    // desktop only
55    var html = jQuery('html');
56    // var scrollPosition = html.data('scroll-position');
57    html.css('overflow', html.data('previous-overflow'));
58    window.scrollTo(scrollPosition[0], scrollPosition[1])
59}
60
61document.ontouchmove = function(e){
62    if(disableScroll){
63        e.preventDefault();
64    }
65}