I figured out that when using a CoreAudio AU graph, AUGraphStart() will display the playback indicator in the iOS status bar and the iOS multitasking bar, and AUGraphStop() will clear them.
iOS - updating the media play/pause state in the multitasking bar
-
13-04-2022 - |
Question
We have a working app that uses an AU graph - CoreAudio API - to play audio. The graph is always running, and the play/pause state of the various source material is managed in the graph rendering callback functions. We successfully respond to UIEventTypeRemoteControl events, and we successfully update the lock-screen with the meta-data for the currently playing content using MPNowPlayingInfoCenter.
The one missing piece is to update the state of the play/pause button in the iOS multitasking bar. It is always in the "pause" (||) mode, even when the app audio is already paused. It never switches to its "play" (>) state.
Which API is used to update the play/pause button state?
Solution 2
OTHER TIPS
Change MPNowPlayingInfo dictionary, set new parameter
MPNowPlayingInfoPropertyPlaybackRate to 1.0f to show pause button
MPNowPlayingInfoPropertyPlaybackRate to 0.0f to show play button
From play button - to - pause button
Class playingInfoCenter = NSClassFromString(@"MPNowPlayingInfoCenter");
if(playingInfoCenter) {
NSMutableDictionary *songInfo = [NSMutableDictionary dictionaryWithDictionary:[MPNowPlayingInfoCenter defaultCenter].nowPlayingInfo];
//[songInfo setObject:songTitle forKey:MPMediaItemPropertyTitle];
//[songInfo setObject:songArtist forKey:MPMediaItemPropertyArtist];
[songInfo setObject:[NSNumber numberWithFloat:1.0f] forKey:MPNowPlayingInfoPropertyPlaybackRate];
[MPNowPlayingInfoCenter defaultCenter].nowPlayingInfo = songInfo;
}
From pause button - to - play button
Class playingInfoCenter = NSClassFromString(@"MPNowPlayingInfoCenter");
if(playingInfoCenter) {
NSMutableDictionary *songInfo = [NSMutableDictionary dictionaryWithDictionary:[MPNowPlayingInfoCenter defaultCenter].nowPlayingInfo];
//[songInfo setObject:songTitle forKey:MPMediaItemPropertyTitle];
//[songInfo setObject:songArtist forKey:MPMediaItemPropertyArtist];
[songInfo setObject:[NSNumber numberWithFloat:0.0f] forKey:MPNowPlayingInfoPropertyPlaybackRate];
[MPNowPlayingInfoCenter defaultCenter].nowPlayingInfo = songInfo;
}