Menu Reveal By Page Rotate Animation

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There are many different approaches to menus on websites. Some menus are persistent, always in view and display all the options. Other menus are hidden by design and need to be opened to view the options. And there are even additional approaches on how hidden menus reveal their menu items. Some fly out and overlap the content, some push the content away, and others will do some sort of full-screen deal.

Whatever the approach, they all have their pros and cons and the right one depends on the situation where it’s being used. Frankly, I tend to like fly-out menus in general. Not for all cases, of course. But when I’m looking for a menu that is stingy on real estate and easy to access, they’re hard to beat.

What I don’t like about them is how often they conflict with the content of the page. A fly-out menu, at best, obscures the content and, at worst, removes it completely from the UI.

I tried taking another approach. It has the persistence and availability of a fixed position as well as the space-saving attributes of a hidden menu that flies out, only without removing the user from the current content of the page.

Here’s how I made it.

The toggle

We’re building a menu that has two states — open and closed — and it toggles between the two. This is where the Checkbox Hack comes into play. It’s perfect because a checkbox has two common interactive states — checked and unchecked (there’s also the indeterminate) — that can be used to trigger those states.

The checkbox is hidden and placed under the menu icon with CSS, so the user never sees it even though they interact with it. Checking the box (or, ahem, the menu icon) reveals the menu. Unchecking it hides it. Simple as that. We don’t even need JavaScript to do the lifting!

Of course, the Checkbox Hack isn’t the only way to do this, and if you want to toggle a class to open and close the menu with JavaScript, that’s absolutely fine.

It’s important the checkbox precedes the main content in the source code, because the :checked selector we’re going to ultimately write to make this work needs to use a sibling selector. If that’ll cause layout concerns for you, use Grid or Flexbox for your layouts as they are source order independent, like how I used its advantage for counting in CSS.

 The checkbox’s default style (added by the browser) is stripped out, using the appearance CSS property, before adding its pseudo element with the menu icon so that the user doesn’t see the square of the checkbox.

First, the basic markup:

<input type="checkbox"> 
<div id="menu">
  <!--menu options-->
</div>
<div id="page">
  <!--main content-->
</div>

…and the baseline CSS for the Checkbox Hack and menu icon:

/* Hide checkbox and reset styles */
input[type="checkbox"] {
  appearance: initial; /* removes the square box */
  border: 0; margin: 0; outline: none; /* removes default margin, border and outline */
  width: 30px; height: 30px; /* sets the menu icon dimensions */
  z-index: 1;  /* makes sure it stacks on top */
} 


/* Menu icon */
input::after {
  content: "\2255";
  display: block; 
  font: 25pt/30px "georgia"; 
  text-indent: 10px;
  width: 100%; height: 100%;
} 


/* Page content container */
#page {
  background: url("earbuds.jpg") #ebebeb center/cover;
  width: 100%; height: 100%;
}

I threw in the styles for the #page content as well, which is going to be a full size background image.

The transition

Two things happen when the menu control is clicked. First, the menu icon changes to an × mark, symbolizing that it can be clicked to close the menu. So, we select the ::after pseudo element of checkbox input when the input is in a :checked state:

input:checked::after {
  content: "\00d7"; /* changes to × mark */
  color: #ebebeb;
}

Second, the main content (our “earbuds” image) transforms, revealing the menu underneath. It moves to the right, rotates and scales down, and its left side corners get angular. This is to give the appearance of the content getting pushed back, like a door that swings open. 

input:checked ~ #page { 
  clip-path: polygon(0 8%, 100% 0, 100% 100%, 0 92%);
  transform: translateX(40%) rotateY(10deg) scale(0.8); 
  transform-origin: right center; 
  transition: all .3s linear;
} 

I used clip-path to change the corners of the image.

Since we’re applying a transition on the transformations, we need an initial clip-path value on the #page so there’s something to transition from. We’ll also drop a transition on #page while we’re at it because that will allow it to close as smoothly as it opens.

#page {
  background: url("earbuds.jpeg") #ebebeb center/cover; 
  clip-path: polygon(0 0, 100% 0, 100% 100%, 0 100%);
  transition: all .3s linear;
  width: 100%; height: 100%;
}

We’re basically done with the core design and code. When the checkbox is unchecked (by clicking the × mark) the transformation on the earbud image will automatically be undone and it’ll be brought back to the front and centre. 

A sprinkle of JavaScript

Even though we have what we’re looking for, there’s still one more thing that would give this a nice boost in the UX department: close the menu when clicking (or tapping) the #page element. That way, the user doesn’t need to look for or even use the × mark to get back to the content.

Since this is merely an additional way to hide the menu, we can use JavaScript. And if JavaScript is disabled for some reason? No big deal. It’s just an enhancement that doesn’t prevent the menu from working without it.

document.querySelector("#page").addEventListener('click', (e, checkbox = document.querySelector('input')) => { 
  if (checkbox.checked) { checkbox.checked = false; e.stopPropagation(); }
});

What this three-liner does is add a click event handler over the #page element that un-checks the checkbox if the checkbox is in a :checked state, which closes the menu.

We’ve been looking at a demo made for a vertical/portrait design, but works just as well at larger landscape screen sizes, depending on the content we’re working with.

This is just one approach or take on the typical fly-out menu. Animation opens up lots of possibilities and there are probably dozens of other ideas you might have in mind. In fact, I’d love to hear (or better yet, see) them, so please share!

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