This class is a trivial implementation of FocusListener; it provides empty bodies for each of the methods of that interface. When you are not interested in all of these methods, it is often easier to subclass FocusAdapter than it is to implement FocusListener from scratch.
public abstract class FocusAdapter extends Object implements FocusListener {
// Default Constructor: public FocusAdapter()
// Public Instance Methods
public void focusGained(FocusEvent e); // From FocusListener
public void focusLost(FocusEvent e); // From FocusListener
}
Object->FocusAdapter(FocusListener(EventListener))