Detect user input using headsets - iphone

Question

I'm trying to detect user input (a click) on the headphones connected to an iPhone. So far I've only found how to detect interruptions using AVAudioSession. Is AVAudioSession right or is there another way? how?

Answer 1

You want this:
beginReceivingRemoteControlEvents
You implement something this in one of your VCs classes:
// If using a nonmixable audio session category, as this app does, you must activate reception of
// remote-control events to allow reactivation of the audio session when running in the background.
// Also, to receive remote-control events, the app must be eligible to become the first responder.
- (void) viewDidAppear: (BOOL) animated {
[super viewDidAppear: animated];
[[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
[self becomeFirstResponder];
}
- (BOOL) canBecomeFirstResponder {
return YES;
}
// Respond to remote control events
- (void) remoteControlReceivedWithEvent: (UIEvent *) receivedEvent {
if (receivedEvent.type == UIEventTypeRemoteControl) {
switch (receivedEvent.subtype) {
case UIEventSubtypeRemoteControlTogglePlayPause:
[self playOrStop: nil];
break;
default:
break;
}
}
}
See the sample code here.

Answer 2

It is even easier now, as of iOS 7. To execute a block when the headphone play/pause button is pressed:
MPRemoteCommandCenter *commandCenter = [MPRemoteCommandCenter sharedCommandCenter];
[commandCenter.togglePlayPauseCommand addTargetWithHandler:^MPRemoteCommandHandlerStatus(MPRemoteCommandEvent * _Nonnull event) {
NSLog(#"toggle button pressed");
return MPRemoteCommandHandlerStatusSuccess;
}];
or, if you prefer to use a method instead of a block:
[commandCenter.togglePlayPauseCommand addTarget:self action:#selector(toggleButtonAction)];
To stop:
[commandCenter.togglePlayPauseCommand removeTarget:self];
or:
[commandCenter.togglePlayPauseCommand removeTarget:self action:#selector(toggleButtonAction)];
You'll need to add this to the includes area of your file:
#import MediaPlayer;