Android programming tips:

How to hide virtual buttons?

In class AndroidLauncher add these lines of code:

import android.os.Build;
import android.annotation.TargetApi;
...
        // In KITKAT (4.4) and next releases, hide the virtual buttons
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            hideVirtualButtons();
        }

...
    @TargetApi(19)
    private void hideVirtualButtons() {
        getWindow().getDecorView().setSystemUiVisibility(
                View.SYSTEM_UI_FLAG_LAYOUT_STABLE
                        | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                        | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                        | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY
                        | View.SYSTEM_UI_FLAG_FULLSCREEN
                        | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION);
    }

    @Override
    public void onWindowFocusChanged(boolean hasFocus) {
        super.onWindowFocusChanged(hasFocus);
        if (hasFocus) {
            // In KITKAT (4.4) and next releases, hide the virtual buttons
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
                hideVirtualButtons();
            }
        }
    }