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Alain,

When adding or removing Components from a Container you must validate the container.

Rod

Alain M. Gaudrault wrote:
> 
> I have a simple little bean with two buttons on one side, and a label on
> the other.  When I click on a button, the previous label is removed, and
> another is added in its place.  The problem is that nothing changes when
> I click the buttons unless I resize the frame.  And when I uncomment the
> revalidate() lines, it works, but only for one or two clicks, then I get
> the same behaviour where I need to resize the frame.  You'd think that
> adding a component would be enough to cause it to draw itself, but it
> doesn't seem like that's happening.
> 
> Am I missing something fundamental, here?
> 
> ==========
> import java.awt.*;
> import com.sun.java.swing.*;
> import java.awt.event.*;
> 
> public class NoRepaint extends JPanel {
>     BorderLayout borderLayout1 = new BorderLayout();
>     JPanel jPanel1 = new JPanel();
>     JScrollPane jScrollPane1 = new JScrollPane();
>     GridLayout gridLayout1 = new GridLayout();
>     JButton jButton1 = new JButton();
>     JButton jButton2 = new JButton();
>     JLabel jLabel1 = new JLabel();
>     JLabel jLabel2 = new JLabel();
> 
>     public NoRepaint() {
>         try  {
>             jbInit();
>         }
>         catch (Exception ex) {
>             ex.printStackTrace();
>         }
>     }
> 
>     private void jbInit() throws Exception {
>         jPanel1.setLayout(gridLayout1);
>         this.setLayout(borderLayout1);
>         gridLayout1.setRows(2);
>         gridLayout1.setColumns(1);
>         jButton1.setText("jButton1");
>         jButton1.addActionListener(new java.awt.event.ActionListener() {
>             public void actionPerformed(ActionEvent e) {
>                 jButton1_actionPerformed(e);
>             }
>         });
>         jButton2.setText("jButton2");
>         jButton2.addActionListener(new java.awt.event.ActionListener() {
>             public void actionPerformed(ActionEvent e) {
>                 jButton2_actionPerformed(e);
>             }
>         });
>         jLabel1.setText("jLabel1");
>         jLabel2.setText("jLabel2");
>         this.add(jPanel1, BorderLayout.WEST);
>         jPanel1.add(jButton1, null);
>         jPanel1.add(jButton2, null);
>         this.add(jScrollPane1, BorderLayout.CENTER);
>     }
> 
>     void jButton1_actionPerformed(ActionEvent e) {
>         jScrollPane1.getViewport().removeAll();
>         jScrollPane1.getViewport().add(jLabel1, null);
> //        jLabel1.revalidate();
>     }
> 
>     void jButton2_actionPerformed(ActionEvent e) {
>         jScrollPane1.getViewport().removeAll();
>         jScrollPane1.getViewport().add(jLabel2, null);
> //        jLabel2.revalidate();
>     }
> 
>     public static void main(String[] args) {
>         NoRepaint nr = new NoRepaint();
>         JFrame frame = new JFrame("NoRepaint test");
>         frame.addWindowListener(new WindowAdapter() {
>             public void windowClosing(WindowEvent e) {
>                 System.exit(0);
>             }
>         });
>         frame.getContentPane().add(nr, BorderLayout.CENTER);
>         frame.setSize(200, 200);
>         frame.setVisible(true);
> 
>         try {
>             nr.wait();
>         }
>         catch(Exception e) {}
>     }
> }
> ==========
> 
> --
> A tantot.
> 
> http://www.gaudrault.net/
> quality costs *less*