Which method in Activity class is called when the activity is no longer visible to the user?

The method that is called when the activity is no longer visible to the user is onStop(). When an Activity enters the stopped state, it indicates that the user is no longer interacting with the Activity, and it is no longer in the foreground of the application. This is a crucial point in the Activity lifecycle as it allows the system to perform cleanup operations, save data, or release resources that are not needed when the Activity is not visible.

onPause() is the method that gets called before onStop() when an Activity is partially obscured or about to become hidden (for example, when another Activity is being opened over it). onDestroy() is invoked when the activity is finishing or being destroyed by the system, which can happen either due to a user action such as closing the app or the system reclaiming resources. onResume(), conversely, is called when the activity returns to the foreground and the user can start interacting with it again.

Understanding the distinctions among these lifecycle methods is important for managing your Activity's resources and ensuring a smooth user experience in Android applications.