Android bring app to foreground on Firebase notification

Question

I have the following code which brings my Android app to foreground once I receive a Firebase Push notification or FCM.

@ReactMethod
public void backToForeground() {

    Context context = getAppContext();
    String packageName = context.getApplicationContext().getPackageName();
    Intent focusIntent = context.getPackageManager().getLaunchIntentForPackage(packageName).cloneFilter();
    Activity activity = getCurrentActivity();
    boolean isOpened = activity != null;

    if (isOpened) {
        focusIntent.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
        activity.startActivity(focusIntent);
    } else {

        // Custom flag to check whether app was started from this method
        focusIntent.putExtra("FLAG_ON_CALL_BRING_TO_FRONT", "true");

        focusIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK +
                WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED +
                WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD +
                WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON);

        getReactApplicationContext().startActivity(focusIntent);

    }

}

Now in MainActivity I have used the bundle as following:

@Override
protected void onCreate(Bundle savedInstanceState) {
SplashScreen.show(this);
super.onCreate(savedInstanceState);
  Bundle extras = getIntent().getExtras();

        if (extras != null) {

            // Custom flag defined in AppStateManagerModule
            String extraString = extras.getString("FLAG_ON_CALL_BRING_TO_FRONT");

            if (extraString != null) {
                getWindow()
                        .addFlags(
                                WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON |
                                        WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD |
                                        WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED |
                                        WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON
                        );
            }
        }
}

My code is working correctly in the following cases:

When FCM is received on device:

1. If app is open, action is performed
2. If app is in background ie minimized, app opens and action is performed
3. If app is killed, app opens and action is performed
4. If app is killed and phone is locked, app opens on top of lock screen and then action is performed

Now here's the case which doesn't work properly:

5. If I start my app and its in foreground or if its minimized and I lock my phone, my app is running fine and my code brings it to front, it performs the required operation BUT it doesn't show on top of lock screen.

Action is performed fine in point 5 but it doesnt show on top of lock screen.

Answer 1

If app is active or in background, after phone is locked it will still be considered active. So since an activity is active, it can't be thrown on top with intent since its already used to activate the activity.

We need to add window flags on an active activity to bring it to front like this:

 if (isOpened) {

    focusIntent.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);

    activity.startActivity(focusIntent);

    // Adding Window Flags to bring app forward on lock screen

    activity.runOnUiThread(new Runnable() {

        @Override
        public void run() {

            activity.getWindow()
                    .addFlags(
                            WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON |
                                    WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD |
                                    WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED |
                                    WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON
                    );
                    
        }
    });

}