android - How to detect "Recent Apps" system button clicks (Honeycomb+)

Question

I'm wondering what method this button calls.

My game always pauses/resumes correctly except for when I use this button, its seems like this button doesn't call the onPause() and onResume() methods of an Activity. It works if I exit the game, go to another window(like the one on the picture) and then use this button to resume. But If I just press this button, when ingame, the game pauses but the thread dosnt resume like it does every other time, the game kind of just stands still on screen and flickers a bit.

Hard to explain but I hope I'm being sort of clear, if not, ask!

Answer 1

None of standard Activity Lifecycle methods is called when "Recent Apps" button pressed. Activity will stay active after list of recent apps popups. Through semi-transparent left part of this list you can even observe application animation is still running, if you running a game with some animation that didn't handle this situation properly. Actually many of games in Google Play didn't handle this situation properly, even good ones, like Angry Birds.

The only Activity method are getting called when user opens "Recent Apps" list (or returns from it) is onWindowFocusChanged with boolean parameter hasFocus. When user open list of Recent App method onWindowFocusChanged() called with hasFocus equals false, and same method called with hasFocus equals true when user pressing Back in this list.