Registering Broadcast Receiver on Android

[Hitokage]

Hi, I used this scheme but it seems like the receiver also needs to be registered in order to make it work. (Is that right?)
The second step I got from here but the callMethod() function cannot find my java function for registration.

Java.lang.NoSuchMethodError: no non-static method "Lorg/qtproject/qt5/android/bindings/QtActivity;.registerReceiver()V"

So I tried to call it like this but no luck either.

Attempt to invoke virtual method 'android.content.Intent android.content.Context.registerReceiver(android.content.BroadcastReceiver, android.content.IntentFilter)' on a null object reference

I am kinda out of options. What is the right way to simply create an alarm, receive and raise a notification?
Thanks and have a nice day!

Here is the code:
JAVA FILES

public class RecieverRegistrator extends QtActivity {
    public void registerReceiver()
    {
        NotificationReceiver nr = new NotificationReceiver();
        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction("intent_myaction_alarm");
        registerReceiver(nr, intentFilter);
     }
}

public class SetNotificationAlarm
{
    public SetNotificationAlarm() {}

    public static void setAlarm(Context context) {
            Calendar calendar = Calendar.getInstance();
            calendar.set(Calendar.HOUR_OF_DAY, 9);
            calendar.set(Calendar.MINUTE, 55);
            calendar.set(Calendar.SECOND, 0);
            calendar.set(Calendar.MILLISECOND, 0);

            Calendar cur = Calendar.getInstance();

            if (cur.after(calendar)) {
                calendar.add(Calendar.DATE, 1);
            }

            Intent myIntent = new Intent(context, SetNotificationAlarm.class);
            int ALARM1_ID = 10000;
            PendingIntent pendingIntent = PendingIntent.getBroadcast(
                    context, ALARM1_ID, myIntent, PendingIntent.FLAG_UPDATE_CURRENT);
            AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
            alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), AlarmManager.INTERVAL_DAY, pendingIntent);
            }
}

Public class NotificationReceiver extends BroadcastReceiver {
private static NotificationManager m_notificationManager;
private static Notification.Builder m_builder;

@Override
public void onReceive(Context context, Intent intent) {
    Uri alarmSound = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
    try {
        m_notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);

        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
            int importance = NotificationManager.IMPORTANCE_DEFAULT;
            NotificationChannel notificationChannel = new NotificationChannel("Qt", "Qt Notifier", importance);
            m_notificationManager.createNotificationChannel(notificationChannel);
            m_builder = new Notification.Builder(context, notificationChannel.getId());
        } else {
            m_builder = new Notification.Builder(context);
        }

        m_builder.setSmallIcon(R.drawable.icon)
                .setLargeIcon(BitmapFactory.decodeResource(context.getResources(), R.drawable.icon))
                .setContentTitle("A message from Qt!")
                .setContentText("message").setSound(alarmSound)
                .setDefaults(Notification.DEFAULT_SOUND)
                .setColor(Color.GREEN)
                .setAutoCancel(true);

        m_notificationManager.notify(0, m_builder.build());
    } catch (Exception e) {
        e.printStackTrace();
    }
}
}

WHAT I CALL FROM main.cpp

QAndroidJniObject setNotificationAlarm = QAndroidJniObject::fromString("SetNotificationAlarm");
   QAndroidJniObject::callStaticMethod<void>(
       "org/myapp/SetNotificationAlarm",
       "setAlarm",
       "(Landroid/content/Context;)V",
       QtAndroid::androidContext().object(),
       setNotificationAlarm.object<jstring>());

  QtAndroid::androidActivity().callMethod<void>("registerReceiver");

IN MANIFEST

<receiver
           android:name="org.myapp.NotificationReceiver"
           android:enabled="true" />

[Hitokage]

I found a way to register the receiver here. Not sure how I could miss it. There was another mistake with the Intent and IntentFilter which I solved using simple string as here.
More more useful links here and here dealing with receiver when you close the app or make the phone sleep.

[ashajg]

Have u called registerReceiver() method somewhere?

[rcyboom]

@ashajg how to registerReceiver in c++?