src/samples/android/cpphellotriangle/src/main/java/com/google/cpphellotriangle/MainActivity.java

package com.google.cpphellotriangle;

import android.view.View;

import com.google.androidgamesdk.GameActivity;

public class MainActivity extends GameActivity {
    static {
        System.loadLibrary("cpphellotriangle");
    }

    @Override
    public void onWindowFocusChanged(boolean hasFocus) {
        super.onWindowFocusChanged(hasFocus);

        if (hasFocus) {
            hideSystemUi();
        }
    }

    private void hideSystemUi() {
        View decorView = getWindow().getDecorView();
        decorView.setSystemUiVisibility(View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY
                | View.SYSTEM_UI_FLAG_LAYOUT_STABLE | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
                | View.SYSTEM_UI_FLAG_FULLSCREEN);
    }
}