Repeated Game Center Welcome Banners - ios5

Question

How do you prevent the Game Center "Welcome Back" message from displaying every time your app wakes up from sleep? Some apps (like Scramble CE, Jetpack Joyride, and Bubblin) handle it correctly (just one welcome message on launch), while others (like Backgammon NJ) don't (welcome message every time the device wakes up).
The block code that's running is no longer in my control (sent to authenticateWithCompletionHandler), and the welcome message appears even if the block is empty anyway.
This behavior started happening with iOS 5.0 (was fine in 4.x), and happens in both the Simulator and real devices, in the Sandbox and not.
Thanks!

Answer 1

I'm from BivisSoft. We've developed Bubblin.
We have a Singleton that controls GameCenter.
Here is our code...
It's based on tutorial by Jacob Gundersen - http://www.raywenderlich.com/5480/beginning-turn-based-gaming-with-ios-5-part-1.
You can try it!
#pragma mark Singleton
static BSGameCenterManager *sharedHelper = nil;
+ (BSGameCenterManager *) sharedInstance {
if (!sharedHelper) {
sharedHelper = [[BSGameCenterManager alloc] init];
}
return sharedHelper;
}
#pragma mark Initializers
- (id)init {
if ((self = [super init])) {
gameCenterAvailable = [self isGameCenterAvailable];
if (gameCenterAvailable) {
self.localPlayerId = #"";
NSNotificationCenter *nc =
[NSNotificationCenter defaultCenter];
[nc addObserver:self
selector:#selector(authenticationChanged)
name:GKPlayerAuthenticationDidChangeNotificationName
object:nil];
}
}
return self;
}
// Check if GameCenter is Avaiable
- (BOOL)isGameCenterAvailable {
// check for presence of GKLocalPlayer API
Class gcClass = (NSClassFromString(#"GKLocalPlayer"));
// check if the device is running iOS 4.1 or later
NSString *reqSysVer = #"4.1";
NSString *currSysVer = [[UIDevice currentDevice] systemVersion];
BOOL osVersionSupported = ([currSysVer compare:reqSysVer
options:NSNumericSearch] != NSOrderedAscending);
return (gcClass && osVersionSupported);
}
#pragma mark Authentication
- (void)authenticationChanged {
if ([GKLocalPlayer localPlayer].isAuthenticated &&
!self.userAuthenticated) {
NSLog(#"GameCenter authentication changed: player authenticated.");
self.userAuthenticated = TRUE;
self.localPlayerId = [[GKLocalPlayer localPlayer] playerID];
[[NSNotificationCenter defaultCenter] postNotificationName: #"gameCenterPlayerAuthenticated" object: nil userInfo: nil];
[self checkNotSentScores];
} else if (![GKLocalPlayer localPlayer].isAuthenticated &&
self.userAuthenticated) {
NSLog(#"GameCenter authentication changed: player not authenticated");
self.userAuthenticated = FALSE;
self.localPlayerId = #"";
}
}
- (void)authenticateLocalUser {
if (!gameCenterAvailable) return;
NSLog(#"GameCenter authenticating local user...");
if ([GKLocalPlayer localPlayer].authenticated == NO) {
[[GKLocalPlayer localPlayer]
authenticateWithCompletionHandler:nil];
} else {
NSLog(#"GameCenter already authenticated!");
}
}

Answer 2

In the Game Kit programming guide I found this bit of documentation:
All games that support Game Center must authenticate the local player
before using any of Game Center’s features. Your game should
authenticate the player as early as possible after launching. Ideally,
authentication should happen as soon as your game can present a user
interface to the player. When your game authenticates a player, Game
Kit first checks to see whether there is already an authenticated
player on the device. If there is an authenticated player, Game Kit
briefly displays a welcome banner to the player.
It doesn't seem as if you can change this behavior with the public API's.