Scroll overflow menu

The following is a guest post by Hugo Darby-Brown, a talented front-end developer. I’m very glad to have him writing here today about a menu concept he came up with!

Before I start off I’d like to say that this is more of a proof of concept, than a method that I’d recommend using on your next project. This menu uses the WebKit-specific CSS declaration overflow-scrolling: touch so support is a little flakey on older devices, but there are a few polyfills, which I will cover later (should you feel the urge to use this menu).

Setting Out

I wanted to create a horizontal scrolling navigation, similar to that of the iOS taskbar. Lots of responsive menu’s take the approach of displaying list items vertically on small screens, but I wanted to play with the idea of having menu items off the screen and swiping to reveal them.

The scroll-overflow menu by Hugo

The Basic Effect

I wanted the HTML markup to be as clean as possible, this I guess it’s pretty self explanatory.

<header>
  <nav role='navigation'>
    <ul>
      <li><a href="#">Home</a></li>
      <li><a href="#">About</a></li>
      <li><a href="#">Clients</a></li>
      <li><a href="#">Contact</a></li>
    </ul>
  </nav>
  <a href="#" class="nav-toggle">Menu</a>
</header>

This is the CSS that makes the effect happen. I’ve stripped out all the styling to highlight the key components that make the effect work.

nav {
  overflow-x: scroll; /* 1 */
  -webkit-overflow-scrolling: touch; /* 2 */
}

ul {
  text-align: justify; /* 3 */
  width: 30em; /* 4 */
}

ul:after { /* 5 */
  content: '';
  display: inline-block;
  width: 100%;
}

li {
  display: inline-block; /* 6 */
}

Okay, so what’s going on here? In essence we’re creating a navigation that is too large for the screen. We set the overflow to scroll, and the overflow-scroll type to touch to allow for momentum scrolling. Explained in a bit more detail below:

  1. Setting auto will work on some devices, but set this to scroll just to be sure.
  2. This the magic property that enables the native feel scrolling.
  3. Setting this to justify creates equally spaced li’s which takes the headache of working out margins.
  4. You must set the width to a value larger than the sum of all the li’s width.
  5. This is text-align: justify’s version of a clearfix.
  6. This must also be set for the equal spacing to work.

Toggling The Menu

We’re almost done, all we have to do is to deal with the toggling. We could use a CSS hack for this but this is not the point so we’ll just use a tiny bit of JavaScript.

So we set the max-height of the navigation to 0 in order to initially hide it, and add a transition so when we toggle the class .show the menu will appear to slide in from the top, pretty basic mobile menu stuff.

nav {
	max-height: 0;
	transition: .6s ease-in-out;
}

.show {
	max-height: 15em;
}

Throw in some JS to toggle the class, and you’ve got yourself a basic slide down mobile menu.

// jQuery version
$(".nav-toggle").on('click', function (e) {
  $("nav").toggleClass("show");
  e.preventDefault();
});

// Vanilla JS version
document.querySelector('.nav-toggle').onclick = function (e) {
  var nav = document.querySelector('nav');
  nav.classList.toggle('show');
  e.preventDefault();
}

What about larger devices?

A mobile only menu isn’t much use these days is it? So using a few min-width media queries we’ll turn this menu into a responsive mobile first menu.

@media (min-width: 31.25em) {
  nav {
    max-height: none; /* reset the max-height */
    overflow: hidden; /* this prevents the scroll bar showing on large devices */
  }

  ul {
    width: 100%;
  }

  .nav-toggle {
    display: none;
  }
}

Support and polyfills

The support is really not that bad, without being awesome either. As far as I know, it looks like this:

  • iOS 5+
  • Android 3.0
  • Blackberry 6+
  • Windows Phone (IE10) supports momentum scrolling natively

For unsupported browsers, there are a few of polyfills that can help you, should you want to use it:

Final thoughts

I think you’ll see a lot more menu’s taking a horizontal approach in the future, but unfortunately Android 2.X still makes up for a 1/3 of market share of all Android devices, so until that reduces significantly I wouldn’t use this in any serious projects.

I would love to hear your thoughts on -webkit-overflow-scrolling: touch; and the future possibilities.

I would usually embed the demo but, unfortunately iframes don’t play well with overflow-scrolling:touch, so it’s best if you directly check this link with your phone. You could also could play around the code at CodePen (caution! iframes, doesn’t work great on some mobile browsers) or by downloading the files!

Thanks for reading! If you think of anything to improve this menu concept, feel free to share. :)

Hugo Darby-Brown is both a designer and a developer from UK, passionate with front-end technologies especially CSS. You can catch him on Twitter or on his brand new site.