In flutter, how can I register if the headset is suddenly unplugged - flutter

Question

Android java offers to register a BroadcastReceiver checking for AudioManager.ACTION_AUDIO_BECOMING_NOISY, to listen to the system broadcasting an ACTION_AUDIO_BECOMING_NOISY message, when a sound is played but then the headset is unplugged or a Bluetooth device disconnected.
Is there a way to do this in flutter, to respond to the event that e.g. a headset is unplugged while playing sound?
With the hint in the answer below, I got this going, but only in DEBUG mode, not in a release ready APK. This is what I did:
Java:
public class MainActivity extends FlutterActivity {
public static final String STREAM = "XXX";
public static String TAG = "player/java file";
private IntentFilter intentFilter = new IntentFilter(AudioManager.ACTION_AUDIO_BECOMING_NOISY);
private BecomingNoisyReceiver myNoisyAudioStreamReceiver = null;
private class BecomingNoisyReceiver extends BroadcastReceiver {
final EventChannel.EventSink eventSink;
BecomingNoisyReceiver(EventChannel.EventSink eventSink){
super();
this.eventSink = eventSink;
}
#Override
public void onReceive(Context context, Intent intent) {
if (AudioManager.ACTION_AUDIO_BECOMING_NOISY.equals(intent.getAction())) {
Log.w(TAG, "Noisy Receiver activated");
eventSink.success("success");
}
}
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
GeneratedPluginRegistrant.registerWith(this);
new EventChannel(getFlutterView(), STREAM).setStreamHandler(
new EventChannel.StreamHandler() {
#Override
public void onListen(Object args, final EventChannel.EventSink events) {
Log.w(TAG, "adding listener");
myNoisyAudioStreamReceiver = new BecomingNoisyReceiver(events);
registerReceiver(myNoisyAudioStreamReceiver, intentFilter);
}
#Override
public void onCancel(Object args) {
Log.w(TAG, "cancelling listener");
unregisterReceiver(myNoisyAudioStreamReceiver);
}
}
);
}
}
And in Dart, in the class extending State:
static const platform = const EventChannel('XXX');
StreamSubscription _noisySubscription;
in initState():
_noisySubscription = null;
Whenever I need it:
if(_noisySubscription == null){
_noisySubscription = platform.receiveBroadcastStream().listen(_handleNoisy);
}
Whenever it needs to stop:
_noisySubscription.cancel().then((_){_noisySubscription = null;});
Any hint, how to fix this problem?

Answer 1

You can use EventChannel to communicate an event on native part (Android) to Dart part. Ref: https://medium.com/#svenasse/flutter-event-channels-89623ce6c017
(Pseudo) Sample Code (it's not in runable state, but hopefully it gives you idea):
Dart part
void _handleNoisy(noisyEvent) {
debugPrint("noisyEvent $noisyEvent");
}
static const stream =
const EventChannel('com.yourcompany.yourapp/ACTION_AUDIO_BECOMING_NOISY');
StreamSubscription _noisySubscription = stream.receiveBroadcastStream().listen(_handleNoisy);
Java part
public class MainActivity extends FlutterActivity {
public static final String STREAM = "com.yourcompany.yourapp/ACTION_AUDIO_BECOMING_NOISY";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
new EventChannel(getFlutterView(), STREAM).setStreamHandler(
new EventChannel.StreamHandler() {
#Override
public void onListen(Object args, final EventChannel.EventSink dartEvents) {
Log.w(TAG, "adding listener");
noisyEvent = ... // Register
private class BecomingNoisyReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
if (AudioManager.ACTION_AUDIO_BECOMING_NOISY.equals(intent.getAction())) {
dartEvents.success("the payload you want to pass to dart")
}
}
}
}
#Override
public void onCancel(Object args) {
Log.w(TAG, "cancelling listener");
}
}
);
}
}