On Wed, 20 Apr 2011 08:29:08 -0400, Phillip Mills <phillip.mil...@acm.org> said: >I have a simple program that uses code such as: > > MPMusicPlayerController *player = [MPMusicPlayerController > applicationMusicPlayer]; > [player setQueueWithQuery:entityQuery]; > [player beginGeneratingPlaybackNotifications]; > [player play]; > >In case it matters, 'entityQuery' always references a single item. > >What then happens is that my >MPMusicPlayerControllerPlaybackStateDidChangeNotification handler gets called >twice with (playbackState == MPMusicPlaybackStatePlaying). There are no >intervening calls, which first got me wondering how 'playing' to 'playing' can >be defined as a state change. Some debugging revealed that userInfo for the >notification contains a MPMusicPlayerControllerPlaybackStateKey item which is >0 on the first call and 1 on the second. > >Assuming (at least somewhat reasonably) that the userInfo code should match >the advertised state and checking the associated enum, it seems as if the >first call should have reported 'Stopped' rather than 'Playing'. > >Anyone have any better information on this? If there's documentation on when >and why notifications are sent (and the expected state transitions) beyond the >implications in their names, I haven't been able to find it.
It's a fact that certain MPMusicPlayerController notifications tend to be called twice in quick succession. What I do is ignore one of the calls if they are extremely close together in time. It hadn't occurred to me to examine the extra info in the userInfo dictionary; you may have discovered a way of distinguishing the calls, in which case yours is a better solution. m. -- matt neuburg, phd = m...@tidbits.com, <http://www.apeth.net/matt/> A fool + a tool + an autorelease pool = cool! Programming iOS 4! http://www.apeth.net/matt/default.html#iosbook_______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
