title: Temporarly Cover JFrame with JPanel
body: <p>I'm attempting to implement a cross platform swing ribbon control (like office '07+ ish) I have found this easy enough to do with JTabbedPane. I am however stumped on the back stage 'file' menu. What I really need to do is when file is selected on the JTabbedPane is cover the whole JFrame with a JPanel without destroying the JComponents underneath. Is their  a z-index property or something I could do this with?</p>
  
  <p>Your document in 'Normal' word with its tabs ext
  <img src="https://i.stack.imgur.com/bdrih.png" alt="Normal Word Image"></p>
  
  <p>You click file word with its 'backstage' file menu (notice all previous ui components are hidden)
  <img src="https://i.stack.imgur.com/W70cl.png" alt="Word side menu"></p>