JCombox does not work under linux (fedora) could you help me???

Question

Hi All,
I am implementing a GUI for a linux application. This GUI works fine under windows system. But the JCombobox does not work under Linux system. Would you help me to solve it? Thank you very much!..
The problem is that I cannot select any other item except the first item in the dropdown box of JCombobox. There is no event generated when I click the combobox, while events are generated for other Buttons.
This problem exists for the following code when I maximize the window. When the window is minimize to some extend in my problem, it is OK.
Here is the simplify code:
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.Serializable;
import java.util.Vector;
import javax.swing.ComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.event.ListDataEvent;
import javax.swing.event.PopupMenuEvent;
import javax.swing.event.PopupMenuListener;
import java.awt.event.*;
import javax.swing.*;
//carmen
import javax.swing.filechooser.*;
import javax.swing.event.*;
import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.border.*;
//import AlwaysSelectableComboBoxDemo.AlwaysSelectableComboBox;
//import AlwaysSelectableComboBoxDemo.AlwaysSelectableComboBox;
import java.io.*;
import java.util.*;
import java.lang.String.*;
public class Test extends JFrame
     private JComboBox jComboBox1;
     private JComboBox jComboBox2;
     private JPanel contentPane;
     private JTabbedPane jTabbedPane1;
     //Main Tab
     private JPanel Main;
     private JPanel OutputSimSet;
     private JPanel Test;
     private JPanel ScriptGenTab;
     private JPanel ResultTab;
//Result Tab
private JPanel SimResult;
     public Test()
          super();
          //initializeComponent();
          contentPane = (JPanel)this.getContentPane();
          jTabbedPane1 = new JTabbedPane();
          Main = new JPanel();
          OutputSimSet = new JPanel();
          Test = new JPanel();
          ScriptGenTab = new JPanel();
          ResultTab = new JPanel();
          SimResult = new JPanel();
     jComboBox1 = new JComboBox(
                    new String[]{"Item 1","Item 2", "Item 3"});
                    jComboBox1.addActionListener(new ActionListener() {
                    public void actionPerformed(ActionEvent ae) {
                    System.out.println("Yeah");
     jComboBox2 = new JComboBox(
                              new String[]{"Item 1","Item 2", "Item 3"});
                              jComboBox2.addActionListener(new ActionListener() {
                              public void actionPerformed(ActionEvent ae) {
                              System.out.println("Yeah");
          // jTabbedPane1
          jTabbedPane1.addTab("Main", Main);
          jTabbedPane1.addTab("ScriptGenerator", ScriptGenTab);
          jTabbedPane1.addTab("Simulation Result", ResultTab);
          jTabbedPane1.addChangeListener(new ChangeListener() {
               public void stateChanged(ChangeEvent e)
                    jTabbedPane1_stateChanged(e);
          // contentPane
          contentPane.setLayout(new BorderLayout(0, 0));
          contentPane.add(jTabbedPane1, BorderLayout.CENTER);
          // Main
          //Main.setLayout(new FlowLayout(FlowLayout.CENTER, 5, 5));
          Main.setLayout(new BorderLayout(0, 0));
          Main.add(OutputSimSet,BorderLayout.NORTH);
          OutputSimSet.setLayout(new FlowLayout(FlowLayout.CENTER, 5, 5));
          OutputSimSet.add(Test, 0);
          Test.setLayout(new FlowLayout(FlowLayout.CENTER, 5, 5));
          Test.add(jComboBox1,0);
          //ResultTab
          ResultTab.setLayout(new BorderLayout(0, 0));
          ResultTab.setBorder(new TitledBorder(""));
          ResultTab.add(SimResult, BorderLayout.NORTH);
          SimResult.setLayout(new FlowLayout(FlowLayout.CENTER, 5, 5));
          SimResult.add(jComboBox2,0);
          // Test
          this.setTitle("Test");
          this.setLocation(new Point(0, 0));
          this.setSize(new Dimension(600, 500));
          this.setVisible(true);
     public void initializeComponent()
     /** Add Component Without a Layout Manager (Absolute Positioning) */
     private void addComponent(Container container,Component c,int x,int y,int width,int height)
          c.setBounds(x,y,width,height);
          container.add(c);
     // TODO: Add any appropriate code in the following Event Handling Methods
     private void jTabbedPane1_stateChanged(ChangeEvent e)
          System.out.println("\njTabbedPane1_stateChanged(ChangeEvent e) called.");
          // TODO: Add any handling code here
     // TODO: Add any method code to meet your needs in the following area
     // TODO: Add any appropriate code in the following Event Handling Methods
     private void jComboBox1_actionPerformed(ActionEvent e)
          System.out.println("\njComboBox1_actionPerformed(ActionEvent e) called.");
          Object o = jComboBox1.getSelectedItem();
          System.out.println(">>" + ((o==null)? "null" : o.toString()) + " is selected.");
          // TODO: Add any handling code here for the particular object being selected
* Create the GUI and show it. For thread safety,
* this method should be invoked from the
* event-dispatching thread.
private static void createAndShowGUI() {
//Create and set up the window.
Test frame = new Test();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
public static void main(String[] args) {
//Schedule a job for the event-dispatching thread:
//creating and showing this application's GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}

Answer 1

package oct03_JCBox;
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTabbedPane;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class Test extends JFrame
private JComboBox jComboBox1;
private JComboBox jComboBox2;
private JPanel contentPane;
private JTabbedPane jTabbedPane1;
//Main Tab
private JPanel Main;
//private JPanel OutputSimSet;
//private JPanel Test;
private JPanel ScriptGenTab;
private JPanel ResultTab;
//Result Tab
//private JPanel SimResult;
public Test()
     super();
     //initializeComponent();
     contentPane = (JPanel)this.getContentPane();
     jTabbedPane1 = new JTabbedPane();
     Main = new JPanel();
     ScriptGenTab = new JPanel();
     ResultTab = new JPanel();
//     OutputSimSet = new JPanel();
//     Test = new JPanel();
//     SimResult = new JPanel();
     jComboBox1 = new JComboBox(
     new String[]{"Item 1","Item 2", "Item 3"});
     jComboBox1.addActionListener(new ActionListener() {
     public void actionPerformed(ActionEvent ae) {
          System.out.println("Yeah");
     jComboBox2 = new JComboBox(
     new String[]{"Item 1","Item 2", "Item 3"});
     jComboBox2.addActionListener(new ActionListener() {
          public void actionPerformed(ActionEvent ae) {
               System.out.println("Yeah");
     // Main
     //Main.setLayout(new FlowLayout(FlowLayout.CENTER, 5, 5));
     Main.setLayout(new FlowLayout(FlowLayout.CENTER, 5, 5));
     Main.add(jComboBox1);
     //ResultTab  -----     
     ResultTab.setLayout(new FlowLayout(FlowLayout.CENTER, 5, 5));
     ResultTab.add(jComboBox2);
    //      jTabbedPane1
     jTabbedPane1.addTab("Main", Main);
     jTabbedPane1.addTab("ScriptGenerator", ScriptGenTab);
     jTabbedPane1.addTab("Simulation Result", ResultTab);
     jTabbedPane1.addChangeListener(new ChangeListener() {
          public void stateChanged(ChangeEvent e)
               jTabbedPane1_stateChanged(e);
     // contentPane
     contentPane.setLayout(new BorderLayout(0, 0));
     contentPane.add(jTabbedPane1, BorderLayout.CENTER);
     // Test
     this.setTitle("Test");
     this.setLocation(new Point(0, 0));
     this.setSize(new Dimension(600, 500));
     this.setVisible(true);
     public void initializeComponent()
//     /** Add Component Without a Layout Manager (Absolute Positioning) */
//     private void addComponent(Container container,Component c,int x,int y,int width,int height)
//     c.setBounds(x,y,width,height);
//     container.add(c);
     // TODO: Add any appropriate code in the following Event Handling Methods
     private void jTabbedPane1_stateChanged(ChangeEvent e)
     System.out.println("\njTabbedPane1_stateChanged(ChangeEvent e) called.");
     // TODO: Add any handling code here
     // TODO: Add any method code to meet your needs in the following area
     // TODO: Add any appropriate code in the following Event Handling Methods
//     private void jComboBox1_actionPerformed(ActionEvent e)
//     System.out.println("\njComboBox1_actionPerformed(ActionEvent e) called.");
//     Object o = jComboBox1.getSelectedItem();
//     System.out.println(">>" + ((o==null)? "null" : o.toString()) + " is selected.");
//     // TODO: Add any handling code here for the particular object being selected
     * Create the GUI and show it. For thread safety,
     * this method should be invoked from the
     * event-dispatching thread.
     private static void createAndShowGUI() {
     //Create and set up the window.
     Test frame = new Test();
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
     frame.pack();
     frame.setVisible(true);
public static void main(String[] args) {
     //Schedule a job for the event-dispatching thread:
     //creating and showing this application's GUI.
     javax.swing.SwingUtilities.invokeLater(new Runnable() {
     public void run() {
     createAndShowGUI();
} Try this - you use too many unnecessary JPanels.
Which way you prefer with actionPerformed should work either way.
I think your problem was too many unnecessary Panels and set all attributes before it is added, perhaps,
not add the panel first and then try to set attributes like layout, color, etc...