Making a component focusable

Question

I made a class extending JPanel and I want it to be selectable/focusable. I've been looking through the source code of many other classes (like AbstractButton) that have this function, but I still don't really understand what I need to implement or code in my component. They implement quite much and I don't really know what to take. Anyone able to help me, maybe with an example class that implements the basic functions for selectability? Thanks in advance.

Answer 1

1) Run the code as is. Focus toggles between the 2 components
2) Remove the comment and retest. Focus now toggles between the 3 components.
import java.awt.*;
import javax.swing.*;
public class FocusTest extends JFrame
     public FocusTest()
          JPanel panel = new JPanel();
//          panel.setFocusable(true);
          getContentPane().add(panel);
          panel.add(new JCheckBox("One"));
          panel.add(new JCheckBox("Two"));
          getContentPane().add( panel );
     public static void main(String[] args)
          FocusTest frame = new FocusTest();
          frame.setDefaultCloseOperation( EXIT_ON_CLOSE );
          frame.pack();
          frame.setLocationRelativeTo( null );
          frame.setVisible(true);
}