SafeArea & MediaQuery

This page discusses how and when to use the SafeArea and MediaQuery widgets.

When running your app on the latest devices, you might encounter bits of the UI being blocked by cutouts on the device's screen. You can fix this with the SafeArea widget, which insets its child widget to avoid intrusions (like notches and camera cutouts), as well as operating system UI (such as the status bar on Android), or by rounded corners of the physical display.

If you don't want this behavior, the SafeArea widget allows you to disable padding on any of its four sides. By default, all four sides are enabled.

It's generally recommended to wrap the body of a Scaffold widget in SafeArea as a good place to start, but you don't always need to put it this high in the Widget tree.

For example, if you purposefully want your app to stretch under the cutouts, you can move the SafeArea to wrap whatever content makes sense, and let the rest of the app take up the full screen.

Using SafeArea ensures that your app content won't be cut off by physical display features or operating system UI, and sets your app up for success even as new devices with different shapes and styles of cutouts enter the market.

How does SafeArea do so much in a small amount of code? Behind the scenes it uses the MediaQuery object.

As discussed in the SafeArea section, MediaQuery is a powerful widget for creating adaptive apps. Sometimes you'll use MediaQuery directly, and sometimes you'll use SafeArea, which uses MediaQuery behind the scenes.

MediaQuery provides lots of information, including the app's current window size. It exposes accessibility settings like high contrast mode and text scaling, or if the user is using an accessibility service like TalkBack or VoiceOver. MediaQuery also contains info about the features of your device's display, such as having a hinge or a fold.

SafeArea uses the data from MediaQuery to figure out how much to inset its child Widget. Specifically, it uses the MediaQuery padding property, which is basically the amount of the display that's partially obscured by system UI, display notches, or status bar.

So, why not use MediaQuery directly?

The answer is that SafeArea does one clever thing that makes it beneficial to use over just raw MediaQueryData. Specifically, it modifies the MediaQuery exposed to SafeArea's children to make it appear as if the padding added to SafeArea doesn't exist. This means that you can nest SafeAreas, and only the topmost one will apply the padding needed to avoid the notches as system UI.

As your app grows and you move widgets around, you don't have to worry about having too much padding applied if you have multiple SafeAreas, whereas you would have issues if using MediaQueryData.padding directly.

You can wrap the body of a Scaffold widget with a SafeArea, but you don't have to put it this high in the widget tree. The SafeArea just needs to wrap the contents that would cause information loss if cut off by the hardware features mentioned earlier.

For example, if you purposefully want your app to stretch under the cutouts, you can move the SafeArea to wrap whatever content makes sense, and let the rest of the app take up the full screen. A side note is that this is what the AppBar widget does by default, which is how it goes underneath the system status bar. This is also why wrapping the body of a Scaffold in a SafeArea is recommended, instead of wrapping the whole Scaffold itself.

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