Problem with JComboBox in a JPanel

I have a JComboBox in a JPanel (with a gridbaglayout), and I add items to the combobox:
String[] stateList={"AL",.....};
JCombobox stateCB=new JComboBox(stateList);
and when I run the application, the states appear in the box, but when I click on the box, there is no drop-down list!
any ideas?

Is the combobox Enabled if it is then after adding it to anything set it to true cause i poersonally tried out as u have given it it works and else if it does not show a list then use the setmodel function and set the model to DefaultComboBoxModel and then add the items using a for loop

Similar Messages

FocusListener problem with JComboBox

Hi,
I am facing a problem with JComboBox. When I make it as Editable it is not Listening to the FocucListener Event....
Please tell me if there is any way to overcome this..
Regards,
Chandan Sharma

I searched the forum using "jcombobox focuslistener editable" and quess what, the first posting I read had the solution.
Search the forum before posting questions.

Strange problem with JComboBox

I am having a strange problem with JComboBox, I created a method as a JComboBox factory which returns a JComboBox filled with items. the method works fine and I can see the items in the JComboBox. The problem is when I try using the method myCombo.SelectedItem(String item); the object myCombo does not set the selected item, it just leaves the item blank (or unselected).
//This method build a JComboBox
public javax.swing.JComboBox makeJComboBox(String[] items) {
javax.swing.JComboBox myComboBox = new javax.swing.JComboBox();
for (int index=0;index<items.length;index++){
myComboBox.addItem(makeObj(items[index]));
return myComboBox;
public Object makeObj(final String item) {
return new Object() {
public String toString() {
return item;
}

Couple of better ways to populate a combo with items-
public javax.swing.JComboBox makeJComboBox(String[]items) {
javax.swing.ComboBoxModel cbModel = new DefaultComboBoxModel(items);
javax.swing.JComboBox myComboBox = new javax.swing.JComboBox(cbModel);
return myComboBox;
}OR
public javax.swing.JComboBox makeJComboBox(String[]items) {
return new javax.swing.JComboBox(items);

Problem with JComboBox in aTable Cell

I try to put JComboBox in JTableCell,
what i want to do is something like this...
Question | Answer |
1. what is your favourite | a. Pizza |
food? | b. Hot Dog |
2. what is your favourite | a. red |
color? | b. blue |
Object[][] data = {
{"1.What is your favourite food?", new AnswerChoices(new String[]{"a.Pizza","b.Hot Dog"})},
{"2.What is your favourite color?", new AnswerChoices(new String[]{"a.red","b.blue"})}
here my code;
//class AnswerChoicesCellEditor
import javax.swing.table.*;
import javax.swing.*;
import java.awt.Component;
import java.awt.event.MouseEvent;
import java.util.EventObject;
import de.falcom.table.*;
public class AnswerChoicesCellEditor extends AbstractCellEditor implements TableCellEditor{
     protected JComboBox mComboBox;
public AnswerChoicesCellEditor(){
     mComboBox = new JComboBox();
     mComboBox.addActionListener(this);
     mComboBox.setEditable(false);
public Component getTableCellEditorComponent(JTable table,Object value,boolean isSelected,int row,int column){
     if(value instanceof AnswerChoices){
          AnswerChoices a = (AnswerChoices)value;
          String[] c = a.getChoices();
          mComboBox.removeAllItems();
          for(int i=0; i < c.length; i++)
               mComboBox.addItem(c);
               mComboBox.setSelectedIndex(a.getAnswer());
     return mComboBox;
public Object getCellEditorValue(){
     int nchoices = mComboBox.getItemCount();
     String[] c = new String[nchoices];
     for(int i = 0; i<nchoices; i++){
          c[i] = mComboBox.getItemAt(i).toString();
     return new AnswerChoices(c,mComboBox.getSelectedIndex());
     //return mComboBox.getSelectedItem(); //here i get but after selection there is no comboBox in tableCell
//the Renderer class
import javax.swing.table.TableCellRenderer;
import javax.swing.*;
import java.awt.Component;
public class AnswerChoicesCellRenderer extends JComboBox implements TableCellRenderer {
     private Object curValue;
/** Creates new AnswerChoiceCellRenderer */
public AnswerChoicesCellRenderer() {
setEditable(false);
public Component getTableCellRendererComponent(JTable table,Object value,boolean isSelected,boolean hasFocus,int row,int column) {
if (value instanceof AnswerChoices) {
AnswerChoices nl = (AnswerChoices)value;
String[] tList = nl.getChoices();
if (tList != null) {
removeAllItems();
for (int i=0; i<tList.length; i++)
addItem(tList[i]);
     setSelectedIndex(AnswerChoices.getAnswer());
     //this.setSelectedItem();
//return this;
//this.getTableCellRendererComponent(table,value,isSelected,hasFocus,row,column);
if (table != null)
if (table.isCellEditable(row, column))
setForeground(CellRendererConstants.EDITABLE_COLOR);
else
setForeground(CellRendererConstants.UNEDITABLE_COLOR);
          setBackground(table.getBackground());
return this;
public class AnswerChoices {
     static int ans = 0;
     String[] choices ;
public AnswerChoices(String[]c,int a){
          choices = c;
          ans          = a;
public AnswerChoices(String[] c){
          this(c,0);
public String[] getChoices(){
     return choices;
public void setAnswer(int a){
     ans = a;
public static int getAnswer(){
     return ans;
//the TableModel i used in my app
import java.awt.Color;
import javax.swing.JTable;
import javax.swing.ListSelectionModel;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableCellEditor;
import javax.swing.table.TableCellRenderer;
import javax.swing.table.TableColumn;
import javax.swing.table.TableModel;
import javax.swing.*;
public class FAL_Table extends JTable {
/** Creates new FAL_Table */
public FAL_Table(DefaultTableModel dtm) {
super(dtm);
setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
setRowSelectionAllowed(false);
setColumnSelectionAllowed(false);
setBackground(java.awt.Color.white);
setDefaultCellEditorRenderer();
private void setDefaultCellEditorRenderer(Class forClass, TableCellEditor editor, TableCellRenderer renderer) {
     setDefaultEditor(forClass, editor);
     setDefaultRenderer(forClass, renderer);
     private void setDefaultCellEditorRenderer() {
          // Setting default editor&renderer of Boolean
          setDefaultCellEditorRenderer(Boolean.class, new BooleanCellEditor(), new BooleanCellRenderer());
          //Setting default editor&renderer of ComboBox
          setDefaultCellEditorRenderer(JComboBox.class, new ComboBoxCellEditor( ),new ComboBoxRenderer());
          // Number class
          // Setting default editor&renderer of java.math.BigDecimal
          setDefaultCellEditorRenderer(java.math.BigDecimal.class,new NumberCellEditor(), new NumberCellRenderer());
          // Setting default editor&renderer of java.math.BigInteger
          setDefaultCellEditorRenderer(java.math.BigInteger.class,new NumberCellEditor(), new NumberCellRenderer());
          // Setting default editor&renderer of java.lang.Byte
          setDefaultCellEditorRenderer(Byte.class,new NumberCellEditor(), new NumberCellRenderer());
          // Setting default editor&renderer of Double
          setDefaultCellEditorRenderer(Double.class,new NumberCellEditor(), new NumberCellRenderer());
          // Setting default editor&renderer of Float
          setDefaultCellEditorRenderer(Float.class,new NumberCellEditor(), new NumberCellRenderer());
          // Setting default editor&renderer of Integer
          setDefaultCellEditorRenderer(Integer.class,new NumberCellEditor(), new NumberCellRenderer());
          // Setting default editor&renderer of Long
          setDefaultCellEditorRenderer(Long.class,new NumberCellEditor(), new NumberCellRenderer());
          // Setting default editor&renderer of Short
          setDefaultCellEditorRenderer(Short.class,new NumberCellEditor(), new NumberCellRenderer());
          // Setting default editor&renderer of String
          setDefaultCellEditorRenderer(String.class,new StringCellEditor(), new StringCellRenderer());
          // Setting default editor&renderer of FileName
          setDefaultCellEditorRenderer(FileName.class,new FileNameCellEditor(), new FileNameCellRenderer());
          // Setting default editor&renderer of Color
          setDefaultCellEditorRenderer(Color.class,new ColorCellEditor(), new ColorCellRenderer());
          setDefaultCellEditorRenderer(AnswerChoices.class, new AnswerChoicesCellEditor(), new AnswerChoicesCellRenderer());
          setDefaultCellEditorRenderer(JSpinner.class, new SpinnerCellEditor(), new SpinnerRenderer());
public Class getCellClass(int row,int col) {
TableModel model = getModel();
if (model instanceof FAL_TableModel) {
FAL_TableModel ptm = (FAL_TableModel)model;
return ptm.getCellClass(row,convertColumnIndexToModel(col));
return model.getColumnClass(convertColumnIndexToModel(col));
public TableCellRenderer getCellRenderer(int row, int column) {
TableColumn tableColumn = getColumnModel().getColumn(column);
TableCellRenderer renderer = tableColumn.getCellRenderer();
if (renderer == null) {
renderer = getDefaultRenderer(getCellClass(row,column));
return renderer;
public TableCellEditor getCellEditor(int row, int column) {
TableColumn tableColumn = getColumnModel().getColumn(column);
TableCellEditor editor = tableColumn.getCellEditor();
if (editor == null) {
editor = getDefaultEditor(getCellClass(row,column));
return editor;
import javax.swing.table.*;
import java.util.Vector;
import java.awt.event.MouseEvent;
import java.util.EventObject;
public class FAL_TableModel extends DefaultTableModel implements TableModel {
public FAL_TableModel() {
this((Vector)null, 0);
public FAL_TableModel(int numRows, int numColumns) {
super(numRows,numColumns);
public FAL_TableModel(Vector columnNames, int numRows) {
super(columnNames,numRows);
public FAL_TableModel(Object[] columnNames, int numRows) {
super(convertToVector(columnNames), numRows);
public FAL_TableModel(Vector data, Vector columnNames) {
setDataVector(data, columnNames);
public FAL_TableModel(Object[][] data, Object[] columnNames) {
setDataVector(data, columnNames);
     public boolean isCellEditable(int row, int col) {
//Note that the data/cell address is constant,
//no matter where the cell appears onscreen.
Object obj = getValueAt(row,col);
if (col != 1){
return false;
     }else{
          return true;
public Class getCellClass(int row,int col) {
Object obj = getValueAt(row,col);
if (obj != null)
     return obj.getClass();
     else
     return Object.class;
public Object getCellValue(int row,int col) {
Object obj = getValueAt(row,col);
          return obj;
my problem is, when i select an item from one of the comboBox in the table the value of the other cells changes too and i have the same problem with JSpinner.
please help i am stuck
Gebi

and when i try to get the current value oa a cell it returns the Component class like this
AnswerChoices@bf1f20 ...

Problem with JComboBox in a fixed JToolBar

Hi,
I've created a JComboBox in a JToolBar that contains all available fonts. When I click on the drop down arrow I only see the first font and a small part of the second. The JComboBox is dropped down in fact just as far as the border of the JToolbar. All the rest isn't visible to me; it seems that they are behind the other components of my JApplet. However, if I move the JToolBar from it's position (as it's a floatable component), there's no problem at all. So I'm wondering why I can't see everything when the JToolBar is docked.... Can anyone help me?
Thanks in advance!!
E_J

it seems that they are behind the other components of my JApplet.Sounds like you are mixing AWT components with your Swing application. Make sure you are using JPanel, JButton ... and not Panel, Button....

Two problems with displaying images in JPanel

Hi,
I need to display some small rectangular images inside a JPanel. These images also need to be componenents as they will have listeners associated with them. I have never had any experience with images, so I might totally be down the wrong path. I was thinking of just creating a class which extends JComponent, and using the graphics drawImage method. However, I don't want each image component to have to know exactly where to draw the image associated with itself. Rather, I want the JPanel which holds all of the images to know how to lay them out.
Is there an easier way to use images?
Which brings me to my second problem. I want these images to overlap each other, so that only a small portion of each is showing (this way I can fit more on the screen), then when the user clicks on one, I can show more of it.
Unfortunately, I don't know of any layout managers which will allow me to overlap components. I could use the drawImage method mentioned above, but like I said, I would like to try to not have each image object try and figure out its location.
any help is greatly appreciated. Thanks!

Hi
there is a better way ; it is called a JLabel ;-)
JLabel myJLabel = new JLabel(new ImageIcon("img/myLogo.gif"));for your second problem, don't use any layout manager like in this code :
myJPanel.setLayout(null);
myJPanel.add(myJLabel);
myJLabel.setBounds(new Rectangle(x, y, width, height);hope it helps
Nico

Event problem with JComboBox

Hi, javamen.
I ve gotten a little problem when working with Itemlistener interface. My combo has 4 options, in which the first one always appears when the applet starts up. Whenever the user DOESNT change it and submit the applet form, throught a button click, the applet gets a NullPointerException. But, if the user changes the option, i always get it, throught my interface' methods(ItemStateChanged). Of course, i know its because there was no combobox event, just a button event (click). So, how can i deal with this situation, since i need to get the combobox option content.
Regards, Euclides.

But, this is the question! I dont know how to initialize the combobox' first option. Help me, please! I am using the addItem method as follow:
MakeJCombo ( JComboBox ComboObj) {
ComboObj.addItem ("option1");
ComboObj.addItem ("option2");
ComboObj.addItem ("option3");
then:
public void itemStateChange(ItemEvent ie) ...
Object origem = ie.getSource()...
if (origem == ComboObj) ...

Problem with JComboBox in j2sdk 1.4.2_01

Hi,
I've got a JComboBox, and I want to change its background color. I use this code:
BasicComboBoxEditor editor = (BasicComboBoxEditor)myJComboBox.getEditor();
editor.getEditorComponent().setBackground(SystemColor.control);
This code works with versions 1.3.1 and 1.4.1, but with version 1.4.2_01 it doesn't.
Can anyone tell me another way to change the background color??
Thanx in advance.

Hi,
I've got a JComboBox, and I want to change its background color. I use this code:
BasicComboBoxEditor editor = (BasicComboBoxEditor)myJComboBox.getEditor();
editor.getEditorComponent().setBackground(SystemColor.control);
This code works with versions 1.3.1 and 1.4.1, but with version 1.4.2_01 it doesn't.
Can anyone tell me another way to change the background color??
Thanx in advance.

The problem with JComboBox

hi,
i have a JComboBox that has 3 items, when user choose one of them,
how can i get it as a string to store into database.
thanks a lot..

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class test extends JFrame implements ItemListener {
JComboBox comboBox;
public test() {
    super("JComboBox");
    String[] comboBoxItems = {
      "one", "two", "three"
    comboBox = new JComboBox(comboBoxItems);
    comboBox.addItemListener(this);
    JPanel panel = new JPanel();
    panel.add(new JLabel("select one"));
    panel.add(comboBox);
    getContentPane().add(panel, BorderLayout.CENTER);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setSize(200,100);
    setLocationRelativeTo(null);
    setVisible(true);
public void itemStateChanged(ItemEvent e) {
    if(e.getStateChange() == ItemEvent.SELECTED) {
      String selection = (String)e.getItem();
      System.out.println("selection = " + selection);
public static void main(String[] args) {
    new test();
}

Problem with JPanel in JFrame

hai ashrivastava..
thank u for sending this one..now i got some more problems with that screen .. actually i am added one JPanel to JFrame with BorderLayout at south..the problem is when i am drawing diagram..the part of diagram bellow JPanel is now not visible...and one more problem is ,after adding 6 ro 7 buttons remaing buttons are not vissible..how to increase the size of that JPanel...to add that JPanel i used bellow code
JFrame f = new JFrame();
JPanel panel = new JPanel();
f.getContentPane().add(BorderLayout.SOUTH, panel);

Hi
JFrame f = new JFrame();
JPanel panel = new JPanel();
// Add this line to ur code with ur requiredWidth and requiredHeight
panel.setPreferredSize(new Dimension(requiredWidth,requiredHeight));
f.getContentPane().add(BorderLayout.SOUTH, panel);
This should solve ur problem
Ashish

Advance level drawing problem with Jframe and JPanel need optimize sol?

Dear Experts,
I m trying to create a GUI for puzzle game following some kind of "game GUI template", but i have problems in that,so i tried to implement that in various ways after looking on internet and discussions about drawing gui in swing, but i have problem with both of these, may be i m doing some silly mistake, which is still out of my consideration. please have a look at these two and recommend me one of them, which is running without problems (flickring and when you enlarge window the board draw copies (tiled) everywhere,
Note: i don't want to inherit jpanel or Jframe
here is my code : import java.awt.BorderLayout;
public class GameMain extends JFrame {
     private static final long serialVersionUID = 1L;
     public int mX, mY;
     int localpoints = 0;
     protected static JTextField[][] squares;
     protected JLabel statusLabel = new JLabel("jugno");
     Label lbl_score = new Label("score");
     Label lbl_scorelocal = new Label("local score");
     protected static TTTService remoteTTTBoard;
     // Define constants for the game
     static final int CANVAS_WIDTH = 800; // width and height of the game screen
     static final int CANVAS_HEIGHT = 600;
     static final int UPDATE_RATE = 4; // number of game update per second
     static State state; // current state of the game
     private int mState;
     // Handle for the custom drawing panel
     private GameCanvas canvas;
     // Constructor to initialize the UI components and game objects
     public GameMain() {
          // Initialize the game objects
          gameInit();
          // UI components
          canvas = new GameCanvas();
          canvas.setPreferredSize(new Dimension(CANVAS_WIDTH, CANVAS_HEIGHT));
          this.setContentPane(canvas);
          this.setDefaultCloseOperation(EXIT_ON_CLOSE);
          this.pack();
          this.setTitle("MY GAME");
          this.setVisible(true);
     public void gameInit() {
     // Shutdown the game, clean up code that runs only once.
     public void gameShutdown() {
     // To start and re-start the game.
     public void gameStart() {
     private void gameLoop() {
     public void keyPressed(KeyEvent e) {
     public void keyTyped(KeyEvent e) {
     public void gameKeyReleased(KeyEvent e) {
          PuzzleBoard bd = getBoard();
          for (int row = 0; row < 4; ++row) {
               for (int col = 0; col < 4; ++col) {
                    if (e.getSource() == squares[row][col]) {
                         if (bd.isOpen(col, row)) {
                              lbl_score.setText("Highest Score = "
                                        + Integer.toString(bd.getPoints()));
                              setStatus1(bd);
                              pickSquare1(col, row, squares[row][col].getText()
                                        .charAt(0));
     protected void pickSquare1(int col, int row, char c) {
          try {
               remoteTTTBoard.pick(col, row, c);
          } catch (RemoteException e) {
               System.out.println("Exception: " + e.getMessage());
               e.printStackTrace();
               System.exit(1);
     // method "called" by remote object to update the state of the game
     public void updateBoard(PuzzleBoard new_board) throws RemoteException {
          String s1;
          for (int row = 0; row < 4; ++row) {
               for (int col = 0; col < 4; ++col) {
                    squares[row][col].setText(new_board.ownerStr(col, row));
          lbl_score.setText("Highest Score = "
                    + Integer.toString(new_board.getPoints()));
          setStatus1(new_board);
     protected void setStatus1(PuzzleBoard bd) {
          boolean locals = bd.getHave_winner();
          System.out.println("local win" + locals);
          if (locals == true) {
               localpoints++;
               System.out.println("in condition " + locals);
               lbl_scorelocal.setText("Your Score = " + localpoints);
          lbl_score
                    .setText("Highest Score = " + Integer.toString(bd.getPoints()));
     protected PuzzleBoard getBoard() {
          PuzzleBoard res = null;
          try {
               res = remoteTTTBoard.getState();
          } catch (RemoteException e) {
               System.out.println("Exception: " + e.getMessage());
               e.printStackTrace();
               System.exit(1);
          return res;
     /** Custom drawing panel (designed as an inner class). */
     class GameCanvas extends JPanel implements KeyListener {
          /** Custom drawing codes */
          @Override
          public void paintComponent(Graphics g) {
               // setOpaque(false);
               super.paintComponent(g);
               // main box; everything placed in this
               // JPanel box = new JPanel();
               setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));
               // add(statusLabel, BorderLayout.NORTH);
               // set up the x's and o's
               JPanel xs_and_os = new JPanel();
               xs_and_os.setLayout(new GridLayout(5, 5, 0, 0));
               squares = new JTextField[5][5];
               for (int row = 0; row < 5; ++row) {
                    for (int col = 0; col < 5; ++col) {
                         squares[row][col] = new JTextField(1);
                         squares[row][col].addKeyListener(this);
                         if ((row == 0 && col == 1) || (row == 2 && col == 3)
                         || (row == 1 && col == 4) || (row == 4 && col == 4)
                                   || (row == 4 && col == 0))
                              JPanel p = new JPanel(new BorderLayout());
                              JLabel label;
                              if (row == 0 && col == 1) {
                                   label = new JLabel("1");
                                   label.setHorizontalAlignment(JLabel.LEFT);
                                   label.setVerticalAlignment(JLabel.TOP);
                              else if (row == 4 && col == 0) {// for two numbers or
                                   // two
                                   // blank box in on row
                                   label = new JLabel("2");
                                   label.setHorizontalAlignment(JLabel.LEFT);
                                   label.setVerticalAlignment(JLabel.TOP);
                              else if (row == 1 && col == 4) {
                                   label = new JLabel("3");
                                   label.setHorizontalAlignment(JLabel.LEFT);
                                   label.setVerticalAlignment(JLabel.TOP);
                              else if (row == 4) {
                                   label = new JLabel("4");
                                   label.setHorizontalAlignment(JLabel.LEFT);
                                   label.setVerticalAlignment(JLabel.TOP);
                              else {
                                   label = new JLabel("5");
                                   label.setHorizontalAlignment(JLabel.LEFT);
                                   label.setVerticalAlignment(JLabel.TOP);
                              label.setOpaque(true);
                              label.setBackground(squares[row][col].getBackground());
                              label.setPreferredSize(new Dimension(label
                                        .getPreferredSize().width, squares[row][col]
                                        .getPreferredSize().height));
                              p.setBorder(squares[row][col].getBorder());
                              squares[row][col].setBorder(null);
                              p.add(label, BorderLayout.WEST);
                              p.add(squares[row][col], BorderLayout.CENTER);
                              xs_and_os.add(p);
                         } else if ((row == 2 && col == 1) || (row == 1 && col == 2)
                                   || (row == 3 && col == 3) || (row == 0 && col == 3)) {
                              xs_and_os.add(squares[row][col]);
                              // board[ row ][ col ].setEditable(false);
                              // board[ row ][ col ].setText("");
                              squares[row][col].setBackground(Color.RED);
                              squares[row][col].addKeyListener(this);
                         } else {
                              squares[row][col] = new JTextField(1);
                              // squares[row][col].addActionListener(this);
                              squares[row][col].addKeyListener(this);
                              xs_and_os.add(squares[row][col]);
               this.add(xs_and_os);
               this.add(statusLabel);
               this.add(lbl_score);
               this.add(lbl_scorelocal);
          public void keyPressed(KeyEvent e) {
          public void keyReleased(KeyEvent e) {
               gameKeyReleased(e);
          public void keyTyped(KeyEvent e) {
     // main
     public static void main(String[] args) {
          SwingUtilities.invokeLater(new Runnable() {
               @Override
               public void run() {
                    new GameMain();
thanks a lot for your time , consideration and efforts.
jibby
Edited by: jibbylala on Sep 20, 2010 6:06 PM

jibbylala wrote:
thanks for mentioning as i wasn't able to write complete context here.Yep thanks camickr. I think that Darryl's succinct reply applies here as well.

Problem with JPanel.updateUI()

Hello,
i have a problem with updateUI(), here's a simple example what's wrong. just compile and run the following piece of code and look what happens after 2 seconds: the left panel will be decrease its width after calling updateUI(), but why? is it a bug of updateUI() or is it my fault?
import java.awt.*;
import javax.swing.*;
public class Test extends JPanel
        private JList m_list;
        private DefaultListModel m_listModel;
        private JPanel m_buttons;
        public static GridBagConstraints creategbc (int x, int y, int w, int h, int wx, int wy, int f)
                GridBagConstraints gbc = new GridBagConstraints();
                gbc.gridx = x;
                gbc.gridy = y;
                gbc.gridwidth = w;
                gbc.gridheight = h;
                gbc.weightx = wx;
                gbc.weighty = wy;
                gbc.fill = f;
                gbc.insets = new Insets(5, 5, 5, 5); // kleinen Rahmen ziehen
                return gbc;
        public Test ()
                GridBagLayout gbl = new GridBagLayout();
                setLayout(gbl);
                GridBagConstraints gbc;
                initButtons();
                gbc = creategbc(0, 0, 1, 1, 20, 100, GridBagConstraints.NONE);
                gbc.anchor = GridBagConstraints.NORTH;
                gbl.setConstraints(m_buttons, gbc);
                add(m_buttons);
                initList();
                JScrollPane sp = new JScrollPane(m_list);
                gbc = creategbc(1, 0, 1, 1, 100, 100, GridBagConstraints.BOTH);
                gbl.setConstraints(sp, gbc);
                add(sp);
        public void addItem (String item)
                m_listModel.addElement(item);
        public void initList ()
                m_listModel = new DefaultListModel();
                m_list = new JList(m_listModel);
        public void initButtons ()
                m_buttons = new JPanel();
                m_buttons.setLayout(new GridLayout(4, 1, 0, 20));
                m_buttons.add(new JButton("Neu"));
                m_buttons.add(new JButton("Bearbeiten"));
                m_buttons.add(new JButton("L�schen"));
                m_buttons.add(new JButton("Abfrage"));
        public static void main (String[] args)
                JFrame f = new JFrame();
                Test t = new Test();
                f.setContentPane(t);
                f.setSize(600, 450);
                f.setVisible(true);
                try
                        Thread.sleep(2000);
                catch (Exception e)
                t.addItem("Hallo");
                t.updateUI();

Hello,
i have a problem with updateUI(), here's a simple
example what's wrong. just compile and run the
following piece of code and look what happens after 2
seconds: the left panel will be decrease its width
after calling updateUI(), but why? is it a bug of
updateUI() or is it my fault?updateUI() its called when the L&F is changed, there is
rarely a case when you need to call updateUI().
Why do you call updateUI() if you remove the call to updateUI()
everything will work OK.
merry xmas

Problem with Jpanel repaintingl

Hi!
I have a problem with Jpanel.
First , I add a Jscrollpane to the panel and I don't
see it.
Second, I have a paint method in the Jpanel and I do there some painting but when I exe the application I can see the panel painting only when I put the mouse cursor
on the place where the panel need to be.
It is very strange.
Help me.
Yair.

Example code??
Can't tell what's wrong otherwise.
First , I add a Jscrollpane to the panel and I don't
see it.Have you added anything to this JScrollPane? Unless you set the scroll bar policies to always on you won't see anything if you haven't added anything to the scrollpane.
Also, if you're only adding this scrollPane to your JPanel initilise it with
JPanel whippet = new JPanel(new BorderLayout())
.. then when you add your scrollPanel to your JPanel do this to make sure its added slap in the in middle of it:
whippet.add(yourScrollPanel, BorderLayout.CENTER);
Bit more info please - duuuuuuuuuuuuuuuude (man, "Finding Nemo" was well funny didn't you think.. anyways, that's besides the point.... could just be my 8 year old mental age though.. who knows.)?

Problem with JTable and JPanel

Hi,
I'm having problems with a JTable in a JPanel. The code is basicly as follows:
public class mainFrame extends JFrame
        public mainFrame()
                //A menu is implemeted giving rise to the following actions:
                public void actionPerformed(ActionEvent evt)
                        String arg = evt.getActionCommand();
                        if(arg.equals("Sit1"))
                        //cells, columnNames are initiated correctly
                        JTable table = new JTable(cells,columnNames);
                        JPanel holdingPanel = new JPanel();
                        holdingPanel.setLayout( new BorderLayout() );
                        JScrollPane scrollPane = new JScrollPane(holdingPanel);
                        holdingPanel.setBackground(Color.white);
                        holdingPanel.add(table,BorderLayout.CENTER);
                        add(scrollPane, "Center");
                        if(arg.equals("Sit2"))
                                if(scrollPane !=null)
                                        remove(scrollPane);validate();System.out.println("ScrollPane");
                                if(holdingPanel !=null)
                                        remove(holdingPanel);
                                if(table !=null)
                                        remove(table);table.setVisible(false);System.out.println("table");
                        //Put other things on the holdingPanel....
        private JScrollPane scrollPane;
        private JPanel holdingPanel;
        private JTable table;
}The problem is that the table isn't removed. When you choose another situation ( say Sit2), at first the table apparently is gone, but when you press with the mouse in the area it appeared earlier, it appears again. How do I succesfully remove the table from the panel? Removing the panel doesn't seem to be enough. Help is much appreciated...
Best regards
Schwartz

If you reuse the panel and scroll pane throughout the application,
instantiate them in the constructor, not in an often-called event
handler. In the event handler, you only do add/remove of the table
on to the panel. You can't remove the table from the container
which does not directly contain it.
if (arg.equals("Sit2")){
holdingPanel.remove(table);
holdingPanel.revalidate();
holdingPanel.repaint(); //sometimes necessary
}

Problem with JPanel and JDesktopPane

Hi,
I am having a problem with my app and I wonder if someone can see what I am doing wrong. I have a class that extends JFrame that holds a centered JPanel to draw on. There are also 3-4 other JInternalFrames that are in use.
From what I have read to use JDesktopPane to organize the JInternalFrames, all you do is add the JInternalFrames to the JDesktopPane and setContentPane to be the JdesktopPane:
        Jpanel panel = new JPanel();
        JDesktopPane dm = new JDesktopPane();
        setContentPane(dm);
        dm.add(panel, BorderLayout.CENTER);
        dm.add(internalFrame1);
        dm.add(internalFrame2);
        dm.add(internalFrame3);But as soon as I add the panel to the JDesktopPane then my JPanel doesnt show up. As I had it before I was adding the panel to the content pane of the Jframe, and adding the JinternalFrames to the layeredPane like this:
        getContentPane().add(panel, BorderLayout.CENTER);
        lp = getLayeredPane();
        lp.add(internalFrame1);
        lp.add(internalFrame2);
        lp.add(internalFrame3);and this worked but the JInternalFrames behaved badly, not getting focus or moving to the top frame when clicked, which I guess is what JDesktopPane is supposed to do. But how do I get my original JPanel in my JFrame to show up when added to the JDesktopPanel?
Am I missing something here?
Thanks,
Paul

Thanks for your response. I will try that when I get home, although I will be surprised if that works because I am already using setPreferredSize() . It seemed to me that once a Jframe's content pane gets assigned to a JDesktopPane, then the JPanel no longer has anywhere to draw itself, as according to the Sun documentation, you can only add a JInternalFrame to a JDesktopPane.
So I am thinking its not possible to have a JPanel as the content pane of a JFrame while having a JDesktopPane containing my JInternalFrames. Is this indeed the case?
Thanks,
Paul

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