Adjusting padding bottom for navigation in iOS and Android

You know how important it is to ensure that the applications we develop are not only functional but also have a great user interface. Navigation is a key aspect of any application and often involves intricate details such as padding adjustments. Today, we're going to look specifically at how to properly adjust the bottom padding for navigation in iOS and Android PWA.

Understanding the problem

Before we dive into the solutions, it's important to understand the challenge at hand. In certain cases, the navigation bar on iOS and Android appears too close to the edge of the screen. This is particularly noticeable in newer models with notable display changes, such as the home display on the iPhone X and later models.
Often, this problem is caused by the safe area, which is an area that is considered safe to display content without being cut off or obscured by a rounded display, sensor housing, or other hardware elements.

The solution: adjusting the bottom padding via env

First, we will use a meta tag, specifically viewport-fit=cover, to ensure that the viewport fully covers the display area, including the rounded corners or sensor bezel.

<meta name="viewport" content="width=device-width, initial-scale=1.0, viewport-fit=cover" />

The viewport-fit=cover attribute allows the site to render across the entire screen, with the safe-area-inset values representing the margins needed to avoid encroaching on the safe area.
For the navigation itself, we will use CSS to adjust the padding at the bottom:

<AppBar 
    sx={{ top: 'auto',
         bottom: 0,
         height: 'calc( 50px + env(safe-area-inset-bottom) )', // ios android padding bottom system navigation
    >

In this line of code, env(safe-area-inset-bottom)consider is used to take into account the values of safe-area-inset-bottom, which corresponds to the safe area inset at the bottom. Also in the above case, the use of calc() is important because it allows the use of env(safe-area-inset-bottom) inside a mathematical expression. This calculates and adds the fixed 50px value and the value provided by env(safe-area-inset-bottom), ensuring that the padding is perfectly adjusted to the device form factor. And there you have it!

Conclusion

Setting proper bottom padding in navigation bars for both iOS and Android platforms is achieved using a combination of the meta viewport tag, the env function, and the CSS calc function, resulting in a smooth and visually pleasing user experience.