Hi!

I am new to Java and Swing. I have tried to search the net (including
comp.lang.java.gui FAQ), but I cannot figure out what is wrong with
the following test of swing. The window only updates when I am
changing the size of the window. How do I get the program to update
the window all by itself?

The program genereates a random number of lines, and is adding a
random number of lines when pushing a button.

Thanks in advance for any help!

public class Test implements ActionListener {

   Box box;
   int lines;
   Random generator = new Random();

   Test() {
       JFrame jfrm = new JFrame("Random Lines Test");
       jfrm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
       box = Box.createVerticalBox();
       int random = generator.nextInt(9)+1;
       for (int i = 1; i <= random; i++) {
           box.add(new JLabel("Line number " + i));
       }
       lines = random;
       JButton jbRandom = new JButton("Add a random (1-9) number of
lines");
       jbRandom.addActionListener(this);
       jfrm.add(box);
       jfrm.add(jbRandom, BorderLayout.SOUTH);
       jfrm.pack();
       jfrm.setExtendedState(Frame.MAXIMIZED_BOTH);
       jfrm.setVisible(true);
   }

   public void actionPerformed(ActionEvent ae) {
       int random = generator.nextInt(9)+1;
       for (int i = lines; i < lines+random; i++) {
           box.add(new JLabel("Line number " + i));
       }
       lines+=random;
   }

   public static void main(String[] args) {
       SwingUtilities.invokeLater(new Runnable() {
           public void run() {
               new Test();
           }
       });
   }

}