Swing : swing-1.0
Platform : NT

In an application, if JApplet is the top level container, changing the content of the container prevents JTextField and JTextArea from getting focus. (NOTE : this only happens on NT. This bug doesn't show on Solaris)

In the following test case, a JFrame contains a JApplet as the top level container which contains a JButton. Push the JButton to change the content of the container. The new components are JTextField, JTextArea and a JCheckBox. Both JTextField and JTextArea cannot get focus.

/**
 * @author Patience Chu
 */
import com.sun.java.swing.*;
import com.sun.java.swing.text.*;

import java.awt.*;
import java.awt.event.*;
import java.util.*;
import java.io.*;
import java.applet.*;

public class Zippy extends JApplet
{
  //variables.
  public void init(){
    getContentPane().setLayout(new BorderLayout());

    setForeground(Color.black);
    setBackground(Color.lightGray);

    JButton button = new JButton("Push to change content");
    button.setBackground(Color.black);
    button.setForeground(Color.yellow);
    button.addActionListener( new ActionListener() {
      public void actionPerformed(ActionEvent e){
showZippy();
      }
    });

    getContentPane().add("Center",button);
  }

  public void showZippy(){
  
    setCursor(Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR));

    getContentPane().removeAll();
    getContentPane().add("Center",new JTextArea("Hello, This is a JTextArea"));
    getContentPane().add("South",new JTextField("a a JTextField"));
    getContentPane().add("North", new JCheckBox("a JCheckBox"));

    invalidate();
    validate();
    repaint();
    setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));

  }

  /**
    * main method.
    */
  public static void main(String args[]){
    String yourVersion = System.getProperty("java.version");
    System.out.println("Your JDK version: "+yourVersion);

    JFrame frame = new JFrame("Zip File Browser");
    Zippy theApplet = new Zippy();
 
    frame.getContentPane().add(theApplet, "Center");
    frame.setBackground(Color.lightGray);

    frame.setSize(200,100);
    frame.setLocation(300, 300);
    // frame.pack();

    WindowListener l = new WindowAdapter() {
      public void windowClosing(WindowEvent e) {System.exit(0);}
    };
    frame.addWindowListener(l);

    theApplet.init();
    frame.show();
  }

}
patience.chu@Eng 1998-02-13