How to call setUndecorated() after a frame is made visible?

Question

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 setU

Answer 1

Here is a code in how to make ALT + Enter enters Full Screen without the bar mode and Minimize with showing the Title bar and the Start bar:

public class myTest extends JFrame{
 //Your codes...
     //if "ALT" key on hold and "Enter" key pressed with it
     if (evt.isAltDown() && evt.getKeyCode() == evt.VK_ENTER) {    
         //if the JFrame has Title bar
         if (isUndecorated()) {
             //this will dispose your JFrame
             dispose();
             //here to set it with no Title bar
             setUndecorated(false);
             pack();
             setLocationRelativeTo(null);
             //as you dispose your JFrame, you have to remake it Visible..
             setVisible(true);
          } else {
             dispose();
             setUndecorated(true);
             setExtendedState(MAXIMIZED_BOTH);
             setVisible(true);
        }
    }
//your codes
}