title: how can I fully disable resizing a window including the resize icon when the mouse hovers the border?
body: <p>I used: 
  <code>setFixedSize(size());</code>
  to stop the window from resizing, but the resize arrows still appear when the mouse is over the border of the window.</p>
  
  <p>Is there a better way to disable window resizing to avoid showing the arrows when crossing the border?</p>