Allow to detect Ambient mode to switch Watch face display on Wear devices

Watch face Ambient mode detection

Handler handler = new Handler(Looper.getMainLooper());

final DisplayManager displayManager = (DisplayManager) getSystemService(Context.DISPLAY_SERVICE);
displayManager.registerDisplayListener(new DisplayManager.DisplayListener() {
    @Override
    public void onDisplayAdded(int displayId) {

    }

    @Override
    public void onDisplayRemoved(int displayId) {

    }

    @Override
    public void onDisplayChanged(int displayId) {
        try {
            if (displayManager.getDisplay(displayId).getState() == Display.STATE_DOZING) {
                updateFaceDisplay(true);
                Log.d(TAG, "onDisplayChanged: dozing");
            } else {
                updateFaceDisplay(false);
                Log.d(TAG, "onDisplayChanged: not dozing");
    
            }
        } catch (NullPointerException exception) {
        }
    }
}, handler);

Any particular reason why you are catching/ignoring the NullPointerException here?

try {
    ...
} catch (NullPointerException e) {
}

@kentarosu onDestroy() is the perfect place to unregister 😉