title: How to call setUndecorated() after a frame is made visible?
body: <p>In my Swing application, I want the ability to switch between decorated and undecorated without recreating the entire frame. However, the API doesn't let me call <code>setUndecorated()</code> after the frame is made visible.</p>
  
  <p>Even if i call <code>setVisible(false)</code>, <code>isDisplayable()</code> still returns true. The API says the only way to make a frame not-displayable is to re-create it. However, I don't want to recreate the frame just to switch off some title bars.</p>
  
  <p>I am making a full-screenable application that can be switched between fullscreen and windowed modes; It should be able to switch while maintaining the state, etc.</p>
  
  <p>How do I do this after a frame is visible?.</p>