Overlapping shadow effect remains on Navigation Drawer's NavigationView

Question

I have refined the Navigation Drawer Activity project template of Android Studio, which uses Toolbar, v7.app.ActionBarDrawerToggle and

Answer 1

Thanks to hata i have succeed to completely hide system UI, by merging his original code:

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

  if (hasFocus) {
    View decorationView = getWindow().getDecorView();
    decorationView.setSystemUiVisibility(
            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
                    | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY);
  }
}

with the solution code added in onCreate of my Activity before calling inflate:

getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN
    | WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS);

Apparently, the flag WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS was the missing piece to make the full screen work as expected on my device (API 21)