For more details on the meaning of these states, see the
AppLifecycleStatus documentation.

As you might have noticed, only a small minority of the Activity
lifecycle events are available; while FlutterActivity does
capture almost all the activity lifecycle events internally and
send them over to the Flutter engine, they’re mostly shielded
away from you. Flutter takes care of starting and stopping the
engine for you, and there is little reason for needing to
observe the activity lifecycle on the Flutter side in most cases.
If you need to observe the lifecycle to acquire or release any
native resources, you should likely be doing it from the native side,
at any rate.

Here’s an example of how to observe the lifecycle status of the
containing activity:

Layouts

What is the equivalent of a LinearLayout?