A Look Into: HTML5 Fullscreen API

We have always been able to view a whole webpage in fullscreen mode. To do so, you can hit F11 key in Windows, while in OS X you can hit Shift + Command + F. However, there are times when we, as a web developer, want to add a trigger on the webpage to perform the function rather than use those keys.

In addition to providing several new elements, HTML5 also introduced a set of new APIs including one that we are going to discuss in this post, called Fullscreen API. This API allows us to put our website or just a particular element on the webpage in fullscreen (and vice versa) using the browser’s native functionality.

As far as implementation is concerned, this API would be useful particularly for videos, images, online game, and HTML/CSS-based slide presentations.

So, let’s see how it works.

Browser Support

At the time of the writing, this API only works for Google Chrome, Safari and Firefox. Similar to CSS3, the syntax is prefixed as it is still in experimental stage.

Webkit Firefox Description
webkitRequestFullScreen mozRequestFullScreen

The method to send the webpage or specified element fullscreen.

webkitCancelFullscreen mozCancelFullscreen

The method to exit fullscreen mode.

mozFullScreenElement webkitFullScreenElement

The method to whether the element is in fullscreen mode.

It is worth noting that the Fullscreen API is subject to change in the future.

Usage Example

One of the best way to learn a new thing is by example. In this post, we will run a simple project. The idea is we will have an image and a button that will put the image fullscreen or change it back to normal view with a click.

HTML

Let’s start with the HTML markup. We have a <div> element to wrap the image and a <span> element for the button.

 <div id="fullscreen" class="html5-fullscreen-api"> <img src="img/arokanddedes.jpg"> <span class="fs-button"></span> </div> 

CSS

Then, we place the image at the center of the window as well as add a few decorative styles to make it look nicer.

 .demo-wrapper { width: 38%; margin: 0 auto; } .html5-fullscreen-api { position: relative; } .html5-fullscreen-api img { max-width: 100%; border: 10px solid #fff; box-shadow: 0px 0px 50px #ccc; } .html5-fullscreen-api .fs-button { z-index: 100; display: inline-block; width: 32px; height: 32px; position: absolute; top: 10px; right: 10px; cursor: pointer; } 


Image by Arief Bahari

I decided to display the icon in the <span> element using :after pseudo-element, so that later we can change the icon easily through CSS using the content attribute.

 .html5-fullscreen-api .fs-button:after { display: inline-block; width: 100%; height: 100%; font-size: 32px; font-family: 'ModernPictogramsNormal'; color: rgba(255,255,255,.5); cursor: pointer; content: "v"; } .html5-fullscreen-api .fs-button:hover:after { color: rgb(255,255,255); } 

JavaScript

We will use jQuery to make the code a little bit leaner.

As we mentioned, we will send the image fullscreen upon a click. We wrap the function under the jQuery .on method.

 $('.fs-button').on('click', function(){ } 

We first check whether the element is already in fullscreen mode, if this condition returns we will execute the webkitCancelFullScreen to send it to normal view. Otherwise, we will turn it to fullscreen using the webkitRequestFullScreen method, like so.

 $('.fs-button').on('click', function(){ var elem = document.getElementById('fullscreen'); if(document.webkitFullscreenElement) { document.webkitCancelFullScreen(); } else { elem.webkitRequestFullScreen(); }; }); 

Click on the fulllscreen icon, and our image will go fullscreen, as shown in the following screenshot.

Fullscreen CSS

Webkit (as well as Firefox) also provides a set of new pseudo-classes that allow us to add style rules when the element is in fullscreen mode. Say we want to change the background, we can write the style rules this way.

 #fullscreen:-webkit-full-screen { background-image: url('../img/ios-linen.jpg'); width: 100%; } 

Now, you should see the iOS linen texture in fullscreen mode.

That’s it. You can head over to the demo page to see it in action. Since, we do not specify the function with the Firefox syntax, this demo will only work in Webkit Browsers, Google Chrome and Safari

Further Reference

    

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