iPod Touch iOS 5.1.1 Not calling viewDidDisappear:animated - iphone

Question

I've posted this question elsewhere, but as SO is such a great community I'm doing so here as well.
First up, I'm using Cocos2D 2.0-gles20 to put a multiplayer/team oriented game together.
I've been integrating GameKitHelper into the app. To date it's been working just fine on my iPhone4 and iPad2 and in the Simulator, but now when I try to use it on an iPod Touch 4th I'm getting assertions in [CCDirectorIOS startAnimation] because the app is getting a viewWillAppear when it shouldn't and no call to viewDidDisappear when it should.
The reason this matters is that these methods on the CCDirectorIOS class cause Cocos2D to start/stop animation whilst another UIKit view is in front. This is something that I've managed myself with Cocos2D-0.99 but with 2.0 it is handled nicely within the director so that each app doesn't have to handle it specifically.
The GameKitHelper class has the following methods for pushing a GKMatchmakerViewController onto the screen:
-(void) showMatchmakerWithInvite:(GKInvite*)invite
{
GKMatchmakerViewController* inviteVC = [[[GKMatchmakerViewController alloc] initWithInvite:invite] autorelease];
if (inviteVC != nil)
{
inviteVC.matchmakerDelegate = self;
[self presentViewController:inviteVC];
}
}
-(UIViewController*) getRootViewController
{
return [CCDirector sharedDirector];
}
-(void) presentViewController:(UIViewController*)vc
{
UIViewController* rootVC = [self getRootViewController];
[rootVC presentModalViewController:vc animated:YES];
}
-(void) dismissModalViewController
{
UIViewController* rootVC = [self getRootViewController];
[rootVC dismissModalViewControllerAnimated:YES];
}
When I call showMatchmakerWithInvite, on the iPhone4, etc I see a call to viewDidDisappear: on the CCDirectorIOS object which stops animation. This is fine. When the GK view is gone, I see a call to viewWillAppear which restarts the animation. Sweet.
On the iPod Touch however, running exactly the same project, the call to viewDidDisappear is not made, but a call to viewWillAppear is, before the GK view has gone.
I can't fathom why there would be a difference. All devices are running iOS 5.1.1.
It's almost as if the behaviour of UIKit is different on the iPod Touch, but I find that hard to believe. My other thought was that I was looking at a timing issue, but I put some code in to allow the app to keep running even with the problem, but the call to viewDidDisappear never happened.
I can work around this I think by managing the start/stop of animation myself, but I would have preferred not to customise the Cocos2D code.
Does anyone have any ideas?
Thanks

Answer 1

Well, being the impatient person I am, rather than leave it to others and work on something else, I nutted it out.
I turns out that the iPod Touch devices in question had multi player games disabled in the restrictions app. This seems to cause the GK view to not show "properly" and as a result the events like viewDidDisappear: and viewWillAppear: don't occur the way I was expecting.
So I've been able to revert all of my tweaks and instrumentation in the Cocos2D code, and simply apply a correction to the GameKitHelper class to ensure that if features such as multi-player are disabled, the player isn't able to request them.