DrCachetes DrCachetes - 1 year ago 211
Swift Question

Headphones plugin/out detection in Swift

im working on an iphone app for iOS 8.1 that works with core audio to generate frequencies and adjust intensities. In the view controller that i generate the frequencies i need to control if the headphones are plugged out in some moment, i'm already controlling if headphones are connected before proceed to my frequencies generator view with the following function:

- (BOOL)isHeadsetPluggedIn {
AVAudioSessionRouteDescription* route = [[AVAudioSession sharedInstance] currentRoute];
for (AVAudioSessionPortDescription* desc in [route outputs]) {
if ([[desc portType] isEqualToString:AVAudioSessionPortHeadphones])
return YES;
return NO;

this function is in C because im working with core-audio to generate the frequencies, but in the view controllers im working with swift so a need a way to implement a listener to detect the headphones plug-out event and return to the user to the previous view, i don't know if i can use my function isHeadsetPluggedin() with an event listener or i should make a new one.
In my MenuViewController i control if the headphones are plugged in using the following function:

func isHeadsetPluggedIn() -> Bool {
return freqController.isHeadsetPluggedIn();

Answer Source

You can track the route changes by observing AVAudioSessionRouteChangeNotification notification.

//Observe for route changing notification
    [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(handleRouteChange:) name:AVAudioSessionRouteChangeNotification object:[AVAudioSession sharedInstance]];

   -(void)handleRouteChange:(NSNotification *)notif
       NSDictionary *dict = notif.userInfo;
       AVAudioSessionRouteDescription *routeDesc = dict[AVAudioSessionRouteChangePreviousRouteKey];
       AVAudioSessionPortDescription *prevPort = [routeDesc.outputs objectAtIndex:0];
       if ([prevPort.portType isEqualToString:AVAudioSessionPortHeadphones]) {
            //Head phone removed