Is there any way to distinguish between an Android Activity onResume from the home screen?

Question

Is there any way to tell whether an Activity is being resumed (i.e. onResume is called) from the home screen/launcher?

For example, if I have an Application with two activities, A and B.

Scenario 1: Some user action on Activity A will invoke Activity B, bringing it into the foreground - moving Activity A into the background. As Activity A moves into the background, it goes through onPause() and onStop(). The user (now on Activity B) either finishes the Activity or hits the "back" button, bringing Activity A back to the foreground, causing an onRestart(), onStart(), onResume() sequence.

Scenario 2: If the user hits the "home" button while Activity A is in the foreground and then re-invokes the Application from the launcher, it goes through the same lifecycle as in Scenario 1. I.e. User hits the "home" button. Activity goes through onPause() and onStop(). User launches the application again, causing Activity A go come back into the foreground, again going through the same onRestart(), onStart(), onResume() sequence as in Scenario 1.

As far as I can tell, the Activity has no way of knowing how it was resumed, it just knows it is being brought back into view. In fact, I have a feeling that there isn't really as much of a concept of an "Application" in Android - in the sense of something that has a single entry and exit point.

Answer 1

in Scenario 2, your activity will get an onNewIntent call, with the launcher intent passed to it.

Answer 2

You could capture the back button press on Activity B and pass an extra value to Activity A. If there is an extra value then the activity was resumed from pressing back on Activity B, if there is no extra value then the Activity was resumed from being hidden.

Answer 3

Could Acitivity A use startActivityForResult() to start Activity B and use onActivityResult() to detect that Activity B finished?