Dealing with the app going into the background

[mobichan]

I have recently started testing the different states my app can be in when going to the background (pressing the home button). It seems that the exact state of the game is not preserved, since I have a custom pause that is lost when going to the background. If the app returns from the background my pause routine (which is done through groups being enabled/disabled) is always unpaused when returning from the background.

Can anyone explain what happens when the game resumes from a background state? Is the game loop run like a "restart" frame event being called or something similar? This is especially troublesome for dealing with sounds.

[RhysD]

Don't run your pause when the app goes into the background, the iOS should automatically save the current state for you so nothing runs until it returns to the foreground.

Instead, using the iOS object use the reactivation event to check when the app is opened again, then run your pause menu.

[mobichan]

I actually do check on reactivation and pause the game if it wasn't before going to the background. The problem is if a player manually pauses the game, then goes to background, when they return to the game, the game is no longer in a pause state. My code actively checks for the player pressing a "resume" button when the game is paused, so there should be nothing unpausing the game. But some unusual code seems to run when returning to the game from background.

Any idea why?

[DistantJ]

Perhaps it's toggling the pause so the pause turns off when you return to the paused app? Try maybe "App reactivated + App is NOT paused: Pause app"?

[Olivier]

I'm also using a custom pause by enabling/disabling groups and I don't have any problems with the app going to the background/foreground. Basically when the app goes into the background and the game is running, the pause is activated. When the app goes into the background and the pause is already activated, do nothing. When the pause is activated, the user has to push a button to resume the game. Can be seen in action in CrazyCrab. Pseudo-code:

Group.Game{
• [iOS] Application has been deactivated
--> Activate Group.Pause
--> Deactivate Group.Game

• [Button.Pause] Has been Clicked
--> Activate Group.Pause
--> Deactivate Group.Game
}

Group.Pause{
• [Button.Resume] Has been Clicked
--> Activate Group.Game
--> Deactivate Group.Pause
}