When opening the system menu, FocusOut event will be sent to the components
within the frame, and it should be a temporary one just like what we get
when opening a user defined menu, not a permanent one. The following test
case shows the problem.


import java.awt.*;
import java.awt.event.*;

class TestFocus extends Component implements FocusListener {
boolean haveFocus = false;
public TestFocus(){
super();
addFocusListener(this);
addMouseListener(new MouseFocusListener(this));
}

        public Dimension getPreferredSize(){
return new Dimension(200, 150);
        }

public void focusGained(FocusEvent e){
System.out.println("==>FocusGained:" + e);
if (e.getSource() == this){
haveFocus = true;
paint(getGraphics());
}
}

public void focusLost(FocusEvent e){
System.out.println("==>FocusLost :" + e);
if (e.getSource() == this){
haveFocus = false;
paint(getGraphics());
}
}

public void paint(Graphics g){
g.setColor(Color.yellow);
Dimension size = getSize();
g.fillRect(0, 0, size.width, size.height);
if (haveFocus){
g.setColor(Color.black);
g.drawRect(0, 0, size.width - 1, size.height - 1);
g.drawRect(1, 1, size.width - 3, size.height - 3);
}
}

        public static void main(String[] args) {
                Frame f = new Frame("Test Focus");
f.setLayout(new BorderLayout());
                TestFocus test = new TestFocus();
f.add(test);
                f.setSize(new Dimension(320,200));

//f.addFocusListener(test);
                MenuBar mb = new MenuBar();
                Menu m1 = new Menu("menu");
                m1.add( new MenuItem("item1"));
                m1.add( new MenuItem("item2"));
                mb.add(m1);
                f.setMenuBar(mb);
 
                f.addWindowListener( new WindowAdapter() {
                        public void WindowClosing( WindowEvent e ) {
                                e.getWindow().dispose();
                                System.exit(0);
                        }
                        public void WindowClosed( WindowEvent e ) {
                                System.exit(0);
                        }
                } );
f.pack();
                f.setVisible(true);
test.requestFocus();
        }

  class MouseFocusListener extends MouseAdapter {
    private Component target;
    MouseFocusListener(Component target) {
        this.target = target;
    }
    public void mouseClicked(MouseEvent e) {
        target.requestFocus();
    }
  }
}