Custom Notification for incoming call not showing in android

I am trying to make a custom incoming call notification like WhatsApp for my app if I don’t use this custom layout then my notification is working. I am trying this for the first time any help will be appreciated.

This is my FireBaseMessagingService Class

public class MyFireBaseMessagingService extends FirebaseMessagingService {
private String CHANNEL_ID = "channel-02";
private String CHANNEL_NAME = "Channel Ring";
long[] pattern = {500, 500, 500, 500, 500, 500, 500, 500, 500};

@Override
public void onNewToken(@NonNull String s) {
    super.onNewToken(s);
    Log.e("NewToken", s);
    getSharedPreferences("_", MODE_PRIVATE).edit().putString("fb", s).apply();
}

@RequiresApi(api = Build.VERSION_CODES.P)
@Override
public void onMessageReceived(@NonNull RemoteMessage remoteMessage) {
    super.onMessageReceived(remoteMessage);
    Log.e("Notification", remoteMessage.getFrom());

    showSimpleNotification(getApplicationContext(), remoteMessage, remoteMessage.getData().get("title"), remoteMessage.getData().get("body"));
}

public static String getToken(Context context) {
    return context.getSharedPreferences("_", MODE_PRIVATE).getString("fb", "empty");
}

@SuppressLint("RemoteViewLayout")
@RequiresApi(api = Build.VERSION_CODES.P)
public void showFullScreenIntent(RemoteMessage remoteMessage, String title, String body) {

    Intent receiveCallIntent = new Intent(getApplicationContext(), FCMReceiver.class);
    receiveCallIntent.putExtra("appointment_id", remoteMessage.getData().get("appointment_id"));
    receiveCallIntent.putExtra("message", title);
    receiveCallIntent.setAction("RECEIVE_CALL");

    Intent cancelCallIntent = new Intent(getApplicationContext(), FCMReceiver.class);
    receiveCallIntent.putExtra("appointment_id", remoteMessage.getData().get("appointment_id"));
    receiveCallIntent.putExtra("message", "Call Rejected");
    receiveCallIntent.setAction("CANCEL_CALL");

    PendingIntent receiveCallPendingIntent = PendingIntent.getBroadcast(getApplicationContext(), 1200,
            receiveCallIntent, PendingIntent.FLAG_UPDATE_CURRENT);

    PendingIntent cancelCallPendingIntent = PendingIntent.getBroadcast(getApplicationContext(), 1201,
            cancelCallIntent, PendingIntent.FLAG_CANCEL_CURRENT);


    Uri ringtone = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_RINGTONE);
    RemoteViews remoteViews = new RemoteViews(getPackageName(), R.layout.custom_call_notification);
    remoteViews.setImageViewResource(R.id.caller_image, R.drawable.icon);
    remoteViews.setTextViewText(R.id.caller_name, body);
    remoteViews.setTextViewText(R.id.call_type, title);

    remoteViews.setOnClickPendingIntent(R.id.btnAccept, receiveCallPendingIntent);
    remoteViews.setOnClickPendingIntent(R.id.btnDecline, cancelCallPendingIntent);


    @SuppressLint("ResourceAsColor") NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(getApplicationContext(), CHANNEL_ID)
            .setSmallIcon(R.drawable.icon)
            .setStyle(new NotificationCompat.DecoratedCustomViewStyle())
            .setCustomContentView(remoteViews)
            .setCustomHeadsUpContentView(remoteViews)
            .setPriority(NotificationCompat.PRIORITY_MAX)
            .setAutoCancel(true)
            .setTimeoutAfter(30000)
            .setOngoing(true)
            .setVibrate(pattern)
            .setSound(ringtone)
            .setFullScreenIntent(receiveCallPendingIntent, true);

    NotificationChannel channel = createChannel();

    NotificationManager mNotificationManager = (NotificationManager)
            getSystemService(Context.NOTIFICATION_SERVICE);
    Notification incomingCallNotification = notificationBuilder.build();
    mNotificationManager.createNotificationChannel(channel);
    mNotificationManager.notify(120, incomingCallNotification);
    
}

This is my channel

 public NotificationChannel createChannel() {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        int importance = NotificationManager.IMPORTANCE_HIGH;
        NotificationChannel channel = new NotificationChannel(CHANNEL_ID, CHANNEL_NAME, importance);
        channel.setLockscreenVisibility(Notification.VISIBILITY_PRIVATE);
        channel.setDescription("Call Notifications");
        channel.setSound(Uri.parse("android.resource://" + getApplicationContext().getPackageName() + "/" + R.raw.ringtone),
                new AudioAttributes.Builder().setContentType(AudioAttributes.CONTENT_TYPE_SONIFICATION)
                        .setLegacyStreamType(AudioManager.STREAM_RING)
                        .setUsage(AudioAttributes.USAGE_VOICE_COMMUNICATION).build());
        channel.shouldVibrate();
        channel.enableVibration(true);
        channel.setVibrationPattern(pattern);
        Objects.requireNonNull(getApplicationContext().getSystemService(NotificationManager.class)).createNotificationChannel(channel);

        return channel;
    }
    return null;
}

This is my FCMReceiver Class

public class FCMReceiver extends BroadcastReceiver {
private Context mContext;
private String mTitle;
private String mContent;
String action = "";


@Override
public void onReceive(Context context, Intent intent) {
    if (context != null) {
        mContext = context;
    }

    Log.e("Receiver", "Receiver a notification");
    mTitle = intent.getStringExtra("message");
    if (mTitle != null && !mTitle.isEmpty()) {
        Log.e("action", "message : " + mTitle);
        performActionClicks(context, mTitle, intent);

        Intent iclose = new Intent(Intent.ACTION_CLOSE_SYSTEM_DIALOGS);
        context.sendBroadcast(iclose);
        context.stopService(new Intent(context, MyFireBaseMessagingService.class));
    }

    if (intent.getStringExtra("gcm.notification.title") != null) {
        if (intent.getStringExtra("gcm.notification title").equalsIgnoreCase("New Appointment")) {
            ActivityManager.RunningAppProcessInfo myProcess = new ActivityManager.RunningAppProcessInfo();
            ActivityManager.getMyMemoryState(myProcess);
            boolean isInBackground = myProcess.importance != ActivityManager.RunningAppProcessInfo.IMPORTANCE_FOREGROUND;
            if (isInBackground) {
                Intent launchIntent = new Intent(context, HomeActivity.class);
                launchIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                launchIntent.putExtra("appointment_id", intent.getStringExtra("appointment_id"));
            }
        }
    }
    if (intent.getStringExtra("notification") != null) {

    }
}

private void performActionClicks(Context context, @NonNull String mTitle, Intent intent) {
        if (!mTitle.isEmpty()) {
            if (mTitle.equalsIgnoreCase("Ringing")) {
                Intent intentCallReceive = new Intent(context, VideoChatViewActivity.class)
                        .putExtra("appointment_id", intent.getStringExtra("appointment_id"));
                intentCallReceive.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TOP);
                mContext.startActivity(intentCallReceive);

                NotificationManagerCompat.from(mContext).cancel(null, 120);
                

            } else if (mTitle.equalsIgnoreCase("Declined")) {
                
            } else if (mTitle.equalsIgnoreCase("Call Rejected")) {

                NotificationManagerCompat.from(mContext).cancel(null, 120);
                

            }
        }
    }

Answer

In you NotificationBuilder you need to set notification category to NotificationCompat.CATEGORY_CALL and style to NotificationCompat.BigTextStyle() like this

NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(getApplicationContext(), CHANNEL_ID)
        .setSmallIcon(R.drawable.icon)
        .setStyle(new NotificationCompat.DecoratedCustomViewStyle())
        .setCustomContentView(remoteViews)
        .setCustomHeadsUpContentView(remoteViews)
        .setPriority(NotificationCompat.PRIORITY_MAX)
        .setAutoCancel(true)
        .setTimeoutAfter(30000)
        .setStyle(NotificationCompat.BigTextStyle())
        .setCategory(NotificationCompat.CATEGORY_CALL)
        .setOngoing(true)
        .setVibrate(pattern)
        .setSound(ringtone)
        .setFullScreenIntent(receiveCallPendingIntent, true);