붉은 돌고래~

* Audio route 변경 시 Notification 수신 방법. (예. Headphones plugged/unplugged) 

     [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(routeChanged:) name:AVAudioSessionRouteChangeNotification object:nil];

- (void)routeChanged:(NSNotification *)notification

{

   NSNumber *reason = [notification.userInfo objectForKey:AVAudioSessionRouteChangeReasonKey];

   if ([reason unsignedIntegerValue] == AVAudioSessionRouteChangeReasonNewDeviceAvailable) {

   } else if ([reason unsignedIntegerValue] == AVAudioSessionRouteChangeReasonOldDeviceUnavailable) {       

   }

}

   - 연관 Notification : AVAudioSessionSilenceSecondaryAudioHintNotification, AVAudioSessionMediaServicesWereLostNotification, AVAudioSessionMediaServicesWereResetNotification, AVAudioSessionInterruptionNotification

* Headphone 이용 시 이벤트 수신 방법.

   // Headphones의 played/paused event 수신. (예. Apple EarPods 일 경우, Center Button 한번 클릭)

   // !!특이점

   //   - Apple EarPods 일 경우, togglePlayPauseCommand를 수신.

   //   - 일반 Bluetooth Headphones 일 경우, 아래의 playCommand/pauseCommand를 수신. (왜??? ;;;;)

   MPRemoteCommandCenter *commandCenter = [MPRemoteCommandCenter sharedCommandCenter];

   [commandCenter.togglePlayPauseCommand addTarget:self action:@selector(command)];

   // Headphones의 played event 수신

   commandCenter.playCommand.enabled = YES;

   [commandCenter.playCommand addTarget:self action:@selector(playCommand)];

   // Headphones의 paused event 수신

   commandCenter.pauseCommand.enabled = YES;

   [commandCenter.pauseCommand addTarget:self action:@selector(pauseCommand)];

   // Headphones의 Next track event 수신. (예. Apple EarPods 일 경우, Volume up 버튼을 두번 클릭)

   commandCenter.nextTrackCommand.enabled = YES;

   [commandCenter.nextTrackCommand addTarget:self action:@selector(nextTrackCommand)];

   // Headphones의 Previous track event 수신. (예. Apple EarPods 일 경우, Volume down 버튼을 두번 클릭)

   commandCenter.previousTrackCommand.enabled = YES;

   [commandCenter.previousTrackCommand addTarget:self action:@selector(previousTrackCommand)];

또는, 

UIResponse를 상속받는 AppDelegate 에서 아래 메소드를 통해 이벤트를 받을 수 있음.

- (void)remoteControlReceivedWithEvent:(nullable UIEvent *)event