Combobox getSelectedItem method

Hi
I have a problem in retrieving combobox values.
I have a frame window with 3 textfield, 1 Combobox and 3 buttons. When I click "Ok" the frame must be closed, and i want to save the values stored in textfields and combobox at that moment. I have a problem with this last one. I get an NullerPointer exception when I try to use Combobox's getSelectedItem() method. This happen inside actionPerformed function, the one associated with OK button. Outside this function I can access combobox without problems.
Any idea?
I hope I explained clearly. If necessary I'll post some code...

RTFAPI:
<h3>javax.swing.JComboBox.getSelectedItem</h3>
Returns the current selected item....
<h4>Returns:</h4>
the current selected Object
You get back what you put in. If you populated the JComboBox with String objects, you get back String objects.
If you populated the JComboBox with any other class of objects, the displayed value is that returned from the toString () method of the class, and getSelectedItem returns a reference to the object used for populating it.
db

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Problem with combobox.select method in 2007A

Hi,
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Hi Julien,
i tried it as
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import com.sun.java.swing.plaf.motif.*;
import com.sun.java.swing.plaf.windows.*;
import java.awt.*;
import java.awt.event.*;
import java.text.*;
import java.util.*;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.event.*;
import javax.swing.plaf.*;
import javax.swing.plaf.basic.*;
import javax.swing.plaf.metal.*;
import javax.swing.table.*;
public class DateComboBox extends JComboBox
    public DateComboBox()
    public DateComboBox(int raekke,DefaultTableModel model,JTable tabel)
        this.raekke=raekke;
        this.model=model;
        this.tabel=tabel;
    public void setDateFormat(SimpleDateFormat dateFormat)
        this.dateFormat = dateFormat;
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        // Could put extra logic here or in renderer when item is instanceof Date, Calendar, or String
        // Dont keep a list ... just the currently selected item
        removeAllItems(); // hides the popup if visible
        addItem(item);
        super.setSelectedItem(item);
    public void setText(String texte)
        setSelectedItem(texte);
    public String getText()
        return (String)this.getSelectedItem();
    public void setRaekke(int raekke)
        this.raekke=raekke;
    public void updateUI()
        ComboBoxUI cui = (ComboBoxUI) UIManager.getUI(this);
        if (cui instanceof MetalComboBoxUI)
            cui = new MetalDateComboBoxUI();
        } else if (cui instanceof MotifComboBoxUI)
            cui = new MotifDateComboBoxUI();
        } else if (cui instanceof WindowsComboBoxUI)
            cui = new WindowsDateComboBoxUI();
        setUI(cui);
    // Inner classes are used purely to keep DateComboBox component in one file
    // UI Inner classes -- one for each supported Look and Feel
    class MetalDateComboBoxUI extends MetalComboBoxUI
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            return new DatePopup( comboBox );
    class WindowsDateComboBoxUI extends WindowsComboBoxUI
        protected ComboPopup createPopup()
            return new DatePopup( comboBox );
    class MotifDateComboBoxUI extends MotifComboBoxUI
        protected ComboPopup createPopup()
            return new DatePopup( comboBox );
    // DatePopup inner class
    class DatePopup implements
    ComboPopup,
    MouseMotionListener,
    MouseListener,
    KeyListener,
    PopupMenuListener
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            addKeyListener(this);
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            background = UIManager.getColor("ComboBox.background");
            foreground = UIManager.getColor("ComboBox.foreground");
            selectedBackground = UIManager.getColor("ComboBox.selectionBackground");
            selectedForeground = UIManager.getColor("ComboBox.selectionForeground");
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            try
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                calendar.setTime( dateFormat.parse( comboBox.getSelectedItem().toString() ) );
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            {e.printStackTrace();}
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            popup.setVisible(false);
        protected JList list = new JList();
        public JList getList()
            return list;
        public MouseListener getMouseListener()
            return this;
        public MouseMotionListener getMouseMotionListener()
            return this;
        public KeyListener getKeyListener()
            return null;
        public boolean isVisible()
            return popup.isVisible();
        public void uninstallingUI()
            popup.removePopupMenuListener(this);
        // end ComboPopup method implementations
        //======================================
        //===================================================================
        // begin Event Listeners
        // MouseListener
        public void mousePressed( MouseEvent e )
        // something else registered for MousePressed
        public void mouseClicked(MouseEvent e)
        public void mouseReleased( MouseEvent e )
            if (!SwingUtilities.isLeftMouseButton(e))
                return;
            if (!comboBox.isEnabled())
                return;
            if (comboBox.isEditable())
                comboBox.getEditor().getEditorComponent().requestFocus();
            else
                comboBox.requestFocus();
            togglePopup();
        protected boolean mouseInside = false;
        public void mouseEntered(MouseEvent e)
            mouseInside = true;
        public void mouseExited(MouseEvent e)
            mouseInside = false;
        // MouseMotionListener
        public void mouseDragged(MouseEvent e)
        public void mouseMoved(MouseEvent e)
        public void keyPressed(KeyEvent e)
            if(e.getSource()==this)
                if(e.getKeyCode()==KeyEvent.VK_CONTROL)
                    System.out.println("keytyped1");
        public void keyTyped(KeyEvent e)
        public void keyReleased( KeyEvent e )
            if(e.getKeyCode()==KeyEvent.VK_CONTROL)
                System.out.println("keytyped2");
            if ( e.getKeyCode() == KeyEvent.VK_SPACE || e.getKeyCode() == KeyEvent.VK_ENTER )
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        public void popupMenuCanceled(PopupMenuEvent e)
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        //=================================================================
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            label.setText("< ");
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            monthLabel = new JLabel("", JLabel.CENTER);
            monthLabel.setForeground(foreground);
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            header.add(monthLabel);
            header.add(Box.createHorizontalGlue());
            label = createUpdateButton(Calendar.MONTH, 1);
            label.setText(" >");
            label.setToolTipText("N�ste m�ned");
            header.add(label);
            label = createUpdateButton(Calendar.YEAR, 1);
            label.setText(">>");
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            header.add(label);
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            popup.setBorder(BorderFactory.createLineBorder(Color.black));
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                popup.remove(days);
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            days.setBackground(background);
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                int dayInt = setupCalendar.get(Calendar.DAY_OF_WEEK);
                JLabel label = new JLabel();
                label.setHorizontalAlignment(JLabel.CENTER);
                label.setForeground(foreground);
                if (dayInt == Calendar.SUNDAY)
                    label.setText("s�n");
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                    label.setText("man");
                else if (dayInt == Calendar.TUESDAY)
                    label.setText("tir");
                else if (dayInt == Calendar.WEDNESDAY)
                    label.setText("ons");
                else if (dayInt == Calendar.THURSDAY)
                    label.setText("tor");
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                    label.setText("fre");
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                    label.setText("l�r");
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                setupCalendar.roll(Calendar.DAY_OF_WEEK, true);
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            setupCalendar.set(Calendar.DAY_OF_MONTH, 1);
            int first = setupCalendar.get(Calendar.DAY_OF_WEEK);
            for (int i = 0; i < (first-2) ; i++)
                days.add(new JLabel(""));
            for (int i = 1; i <= setupCalendar.getActualMaximum(Calendar.DAY_OF_MONTH); i++)
                final int day = i;
                final JLabel label = new JLabel(String.valueOf(day));
                label.setHorizontalAlignment(JLabel.CENTER);
                label.setForeground(foreground);
                label.addMouseListener(new MouseAdapter()
                    public void mouseReleased(MouseEvent e)
                        label.setOpaque(false);
                        label.setBackground(background);
                        label.setForeground(foreground);
                        calendar.set(Calendar.DAY_OF_MONTH, day);
                        hide();
                        comboBox.requestFocus();
                        if (tabel.isEditing())
                            tabel.getCellEditor(tabel.getEditingRow(),
                            tabel.getEditingColumn()).stopCellEditing();
                        model.setValueAt(dateFormat.format(calendar.getTime()),raekke,1);
                        tabel.requestFocus();
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                        label.setOpaque(true);
                        label.setBackground(selectedBackground);
                        label.setForeground(selectedForeground);
                    public void mouseExited(MouseEvent e)
                        label.setOpaque(false);
                        label.setBackground(background);
                        label.setForeground(foreground);
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        private Calendar calendar;
        private JPopupMenu popup;
        private JLabel monthLabel;
        private JPanel days = null;
        private SimpleDateFormat monthFormat = new SimpleDateFormat("MMM yyyy");
        //        private int antaldage=1;
        private Color selectedBackground;
        private Color selectedForeground;
        private Color background;
        private Color foreground;
    private SimpleDateFormat dateFormat = new SimpleDateFormat("dd-MM-yyyy");
    private int raekke=-1;
    private DefaultTableModel model;
    private JTable tabel;
}

come on help plz....

Combobox dropdown functionality

Hi,
I have a combobox dropdown for a Column in my table. it displays "codes Description" something like this
01 Apparel
02 Houseware
03 Kitchenware
I have a query to get this data in the dropdown from a oracle table.
Select LEVEL1_CATEGORY_CD, CATEGORY_DESC From PRODUCT_CATEGORY1
Order By PRODUCT_CATEGORY1.CATEGORY_DESC
I am using setboundsql() method of the Column class in Quicktable.
http://quicktable.org/doc/quick/dbtable/Column.html
I have also tried getting the query data in a hastable as a key/value pair and fill the combo box.
what i need is when user selects something from the dropdown like "02 Houseware" i need only 02 to be filled into my cell. is this possible? right now its filling "02 Houseware" in the dropdown. can you explain stepwise as i am new to swing API.
Thanks.

I guess I am close but doing something silly. thats how I learn.
here is my code snippet,
final JComboBox comboBox;
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Re: Combobox Listener troubles

Your JPanel should not be implementing ItemListener. The ItemListener is added anonymously to the ComboBox:
jComboBox1.addItemListener(new java.awt.event.ItemListener() {
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You're using JBuilder?
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I have a custom combobox editor which supports the autocomplete feature as follows:
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                              - scrollToRow - 1);
                    popupList.scrollRectToVisible(popupList.getCellBounds(
                              scrollToRow + rowsToAdd, scrollToRow + rowsToAdd));
               if (matchCount > 0) {
                    ((PITextField)getEditorComponent()).setSelectionStart(matchCount);
                    ((PITextField)getEditorComponent()).setSelectionEnd(
                              getDocument().getLength());
     public class ComboBoxAutoCompleteUI extends BasicComboBoxUI {
         JList getPopupList() {
             return popup.getList();
     public class ComboBoxAutoCompleteDocument extends PlainDocument {
     public void insertString(int offs, String str, AttributeSet a) throws BadLocationException {
        currentMatchCount = getLength() + str.length();
        String currentText = getText(0, getLength());
        //search the matching string here
        offs = 0;
        remove(0, getLength());
        super.insertString(offs, str, a);
     **************

You need to create a custom CellEditor which will prevent these problems from occurring. The explanation behind the problem and source code for the new editor can be found at Thomas Bierhance's site http://www.orbital-computer.de/JComboBox/. The description of the problem and the workaround are at the bottom of the page.

ComboBox Matrix First Line Empty

Hi,
I have build a Matrix with a combo box ( ...a old story...); but when the form loads, the first line in the combo box is empty.
I start filling the Combo Box from position 0...
Thanks
Rune
oRecordset = ((SAPbobsCOM.Recordset)(oCompany.GetBusinessObject(SAPbobsCOM.BoObjectTypes.BoRecordset)));
bool vmp_Language_EN_bool = true;
m_Language(out vmp_Language_EN_bool);
if (vmp_Language_EN_bool)
    vDoQuery_string = "SELECT [Code],[U_English] FROM [dbo].[@FCSDK_PAY_TYPE]";
else
    vDoQuery_string = "SELECT [Code],[Name] FROM [dbo].[@FCSDK_PAY_TYPE]";
oRecordset.DoQuery(vDoQuery_string);
vm_Recordset_Count_long = oRecordset.RecordCount;
oRecordset.MoveFirst();
SAPbouiCOM.Matrix oMatrix = (SAPbouiCOM.Matrix)oForm.Items.Item("mtx_F_AA").Specific;
SAPbouiCOM.Column oColumn = (SAPbouiCOM.Column)oMatrix.Columns.Item("mtxV_0");
for (vRecordsetIndex_long = 0; vRecordsetIndex_long <= vm_Recordset_Count_long - 1; vRecordsetIndex_long++)
    oColumn.ValidValues.Add(System.Convert.ToString(oRecordset.Fields.Item(0).Value), System.Convert.ToString(oRecordset.Fields.Item(1).Value));
    oRecordset.MoveNext();
oRecordset = null;
System.GC.Collect();

Hi Rune,
I think that's the normal behavior, and is probably desirable. If the first entry were automatically displayed it would become the automatic default, whether the user chose it or not. Plus if rows get added to the source table, the one that displays first might change!   You can always do an edit to make sure it is entered before processing it.
But if you really want a default, you can use the combobox.select method, right after loading it, to display whichever row you desire.
for example:
cb.Select("Visa",BoSearchKey.psk_ByDescription)
"by description" means to select the entry where the description field is = "Visa". You can also
pass it the code for visa & set the searchkey to ByValue.

Runtime help please

Greetings,
First off I will admit that this a part of a project for school. I am not asking for anyone to "give me code" or to "do it for me". I am having a problem tracing a runtime error with the below code. The error only occurs when you choose a selection from the jmenu (null pointer execption on line xyz). the jmenu is supposed to update the display in the JComboBox via the setSelectedItem() and the null pointer points towards the line for the setSelectedItem(). Any assistance in pointing me towards the source of the error is appreciated.
source code follows:
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
class Polygon extends JFrame implements ActionListener
{   // start Polygon Class
     /* Variable Declarations */
     Color color = Color.red;
     JComboBox comboBox;
     boolean moving;
     boolean overload;
     /* End Variable Declarations */
     Polygon()
     { //start Polygon contructor
          addWindowListener(new WindowAdapter()
                    public void windowClosing(WindowEvent e)
                              System.exit(0);
               }); // ends anon class for window closing (ends program)
     /* Creation of the MenuBar */
     JMenuBar menu = new JMenuBar();
     JMenu menuColor = new JMenu("Color");
     JMenuItem makeRed = new JMenuItem("Red");
          menuColor.add(makeRed);
          makeRed.addActionListener(this);
     JMenuItem makeBlue = new JMenuItem("Blue");
          menuColor.add(makeBlue);
          makeBlue.addActionListener(this);
     JMenuItem makeGreen = new JMenuItem("Green");
          menuColor.add(makeGreen);
          makeGreen.addActionListener(this);
     JMenuItem makeYellow = new JMenuItem("Yellow");
          menuColor.add(makeYellow);
          makeYellow.addActionListener(this);
     menu.add(menuColor);
     setJMenuBar(menu);
     /* End Creation of the MenuBar */
     /* Creation of the Combo box*/
     Object [] items = {"Red", "Blue", "Green", "Yellow"};
     JComboBox comboBox = new JComboBox(items);
     getContentPane().add(comboBox, BorderLayout.SOUTH);
     comboBox.addActionListener(new ActionListener()
               { //start anon class
                    public void actionPerformed(ActionEvent e)
                         { //start action Performed
                              JComboBox comboBox = (JComboBox)e.getSource();
                              String comboString = (String)comboBox.getSelectedItem();
                                   if(comboString.equals("Red"))
                              color = Color.red;
                                   else if(comboString.equals("Green"))
                                        color = Color.green;
                                   else if(comboString.equals("Blue"))
                                        color = Color.blue;
                                   else if(comboString.equals("Yellow"))
                                        color = Color.yellow;
                         } //end actionPerformed
                    } //end anon class
               ); //end function call for anon class
     /* End Creation of the Combobox */
     }// end Polygon contructor
     public void actionPerformed(ActionEvent e)
     { // begins Actions
          JMenuItem menu = (JMenuItem)e.getSource();
          String menuString = menu.getText();
     if(menuString.equals("Yellow"))
     color = Color.yellow;
     comboBox.setSelectedItem("Yellow");
     else if(menuString.equals("Red"))
     color = Color.red;
     comboBox.setSelectedItem("Red");
     else if(menuString.equals("Blue"))
     color = Color.blue;
     comboBox.setSelectedItem("Blue");
     else if(menuString.equals("Green"))
     color = Color.green;
     comboBox.setSelectedItem("Green");
     } //ends Actions
public static void main (String []args)
     JFrame frame = new Polygon();
     frame.setTitle("Project 3");
     frame.setSize(300, 300);
     frame.setVisible(true);
} //end main
}//end Ploygon Class

hi
I checked ur code.
the problem is that u have initialized objects more than one time un necesssarly.
my friend for selecting an item from a combo box there are some methods iside java plz refer to them.
do not use String .equal() ...
i am sue that u will get ue souirce code copiled if u remove those problem,s.

BasicComboPopup issue

Between J2SE 1.5 and Java SE 6 the implementation of javax.swing.plaf.basic.BasicComboPopup changed in a way which breaks our application. The specific change is in the internal InvocationMouseHandler class which causes the popup to hide/unhide. In releases prior to SE 6 it didn't matter if the user clicked on an item that was already selected or not. If the user clicked an item in the popup list, the JComboBox always recieveid a setSelectedIndex() call. This, in turn, not only hid the popup but sent an ActionPerformed event. In SE 6 the BasicComboPopup mouse handler now checks to see if the user clicked on a "different" item than was perviously selected. If it is the same item, the BasicComboPopup simply closes the popup and bypasses the setSelectedIndex() call which, in turn, bypasses the action event. Since nothing "haoppens" in a class that's easy to override in the GUI application I'm a little stuck.
For those who will ask, this manifests itself in our application when users use the keyboard to type-and-narrow to an item or arrow down to an item and then use the mouse to click the selection after the keyboard has been used. When this happens, the combo box simply closes without actually firing the action event. (Yes, they can hit ENTER from there and it works. However, users being users, they immediately noted this change in behavior and requested a "fix". No, I'm not exactly sure why if someone uses the keyboard to navigate to an item that they would want to then use the mouse to select the item they've already navigated to with the keyboard) It is a pretty narrow problem since the issue only happens if the last "keybord selected" item in the list is the one the user clicks. Nonetheless, its a change in the UI behavior that was unexcpected to us and turns out to be hard to solve.
So...
It would seem that I should be able to make my own version of BasicComboPopup with mouse handler behavior that I want and plug it into the UIManager or the LookAndFeel somewhere. I looked at the available keys in the LookAndFeelDefaults and didn't see anything that would do the trick.
Can anyone point me in the right direction if I want to plug my own BasicComboPopup in somewhere?

After taking another look I have a third and I think more appropriate work-around for the specific problem originally posted in this thread and in the java bug mentioned in this thread. It is what I was originally looking for. I basically made the JComboBox behave as it did prior to 1.6 by creating my own custom BasicComboPopup by extending it and replacing the mouse handling. As follows...
First, I made my own custom ComboBoxUI which extends BasicComboBoxUI. This allows me to generate my custom Popup from the combo box...
// MyBasicComboBoxUI.java
import javax.swing.plaf.basic.BasicComboBoxUI;
import javax.swing.plaf.basic.ComboPopup;
public class MyBasicComboBoxUI extends BasicComboBoxUI {
    protected ComboPopup createPopup() {
        return new MyBasicComboPopup( comboBox );
}// MyBasicComboBoxUI.java Next, I created my own ComboPopup which extends BasicComboPopup. This allows me to roll back the mouseReleased() changes made in 1.6 that changed the behavior in ways I didn't like. All of this code is basically replicated from the BasicComboPopup since the Handler class is private in BasicComboBox and could not be extended. Additionally the getHandler() method is private so I had to reimplement the createxxxMouseListerner() methods.
// MyBasicComboPopup.java
import javax.swing.plaf.basic.BasicComboPopup;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JComboBox;
import javax.swing.JComponent;
import javax.swing.SwingUtilities;
public class MyBasicComboPopup extends BasicComboPopup {
    private MouseHandler handler;
    public MyBasicComboPopup( JComboBox combo )      {
        super(combo);
    protected MouseListener createMouseListener() {
        return getMouseHandler();
    protected MouseListener createListMouseListener()     {
        return getMouseHandler();
    private MouseHandler getMouseHandler()     {
        if (handler == null) {
            handler = new MouseHandler();
        return handler;
    private class MouseHandler implements MouseListener {
        public void mouseEntered(MouseEvent e) {}
        public void mouseExited(MouseEvent e) {}
        public void mouseClicked(MouseEvent e) {}
        public void mousePressed(MouseEvent e) {
            if (e.getSource() == list)     {
                return;
            if (!SwingUtilities.isLeftMouseButton(e) || !comboBox.isEnabled())
                return;
            if ( comboBox.isEditable() ) {
                Component comp = comboBox.getEditor().getEditorComponent();
                if ((!(comp instanceof JComponent)) || ((JComponent)comp).isRequestFocusEnabled()) {
                    comp.requestFocus();
            } else
            if (comboBox.isRequestFocusEnabled())     {
                comboBox.requestFocus();
            togglePopup();
        public void mouseReleased(MouseEvent e) {
            if (e.getSource() == list) {
                if (list.getModel().getSize() > 0) {
                   comboBox.setSelectedIndex( list.getSelectedIndex() );
                comboBox.setPopupVisible(false);
                // workaround for cancelling an edited item (bug 4530953)
                if (comboBox.isEditable() && comboBox.getEditor() != null) {
                    comboBox.configureEditor(comboBox.getEditor(), comboBox.getSelectedItem());
                return;
            // JComboBox mouse listener
           Component source = (Component)e.getSource();
            Dimension size = source.getSize();
            Rectangle bounds = new Rectangle( 0, 0, size.width - 1, size.height - 1 );
            if ( !bounds.contains( e.getPoint() ) ) {
                MouseEvent newEvent = convertMouseEvent( e );
                Point location = newEvent.getPoint();
                Rectangle r = new Rectangle();
                list.computeVisibleRect( r );
     if ( r.contains( location ) ) {
                   comboBox.setSelectedIndex( list.getSelectedIndex() );
     comboBox.setPopupVisible(false);
            hasEntered = false;
            stopAutoScrolling();
// MyBasicComboPopup.javaFinally, I set my custom UI as the JComboBox UI
JComboBox c = new JComboBox();
c.setUI(NewMyBasicComboBoxUI());

Trying to get components inside a panel in content pane

Hello,
I am trying to update the combo boxes inside a panel with a list of values(list is stored as an array).
My heirarchy of components is as follows:
frame-->contentpane-->gamepanel-->combopanel-->combobox
i am able pass my frame into my code. now i have to get the combobox to update it.
frame.getcontentpane()this returns to me my contentpane - RIGHT/WRONG???
if right, after this how do i reach the combopanel and get the combobox such that I am able to write
combobox.addItem(array)HELP PLEASEEEEEEEEEEEEE
Thanks,
Manju

Be patient. 30 minutes is not a long time to wait for answers, especially on the weekend. Instead of waiting impatiently why don't you try reading sections from the Swing Tutorial. For example, How to Use Combo Boxes:
http://java.sun.com/docs/books/tutorial/uiswing/components/combobox.html
so how do i keep the reference?Define a class variable for the combo box:
     This works on non editable combo boxes
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.text.*;
public class ComboBoxAction extends JFrame implements ActionListener
     JComboBox comboBox;
     public ComboBoxAction()
          comboBox = new JComboBox();
          comboBox.addActionListener( this );
          comboBox.addItem( "Item 1" );
          comboBox.addItem( "Item 2" );
          comboBox.addItem( "Item 3" );
          comboBox.addItem( "Item 4" );
          // This prevents action events from being fired when the
          // up/down arrow keys are used on the dropdown menu
          comboBox.putClientProperty("JComboBox.isTableCellEditor", Boolean.TRUE);
          getContentPane().add( comboBox );
     public void actionPerformed(ActionEvent e)
          System.out.println( comboBox.getSelectedItem() );
          // make sure popup is closed when 'isTableCellEditor' is used
          comboBox.hidePopup();
     public static void main(String[] args)
          final ComboBoxAction frame = new ComboBoxAction();
          frame.setDefaultCloseOperation( EXIT_ON_CLOSE );
          frame.pack();
          frame.setVisible( true );
}Even though the combo box is created in the constructor, the actionPerformed() method can still access the combo box because it was defined as a class variable.

JTable: renderer problem-urgent

Thanx "pasteven". That url is too good.
I wrote my own renderer for each cell in JTable that uses JCombobox for rendering purpose. But when i select an item in that combo box, some times renderer is not setting the selected item in that combobox. Sometimes when i change the selection of item in the previous cell,it is getting reflected in all other cells of that particular column.
Here is my code. Please help me.
import java.util.*;
import java.io.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.event.*;
import javax.swing.text.*;
import javax.swing.table.TableCellEditor.*;
import javax.swing.table.*;
import javax.swing.DefaultCellEditor;
public class Render extends javax.swing.JFrame {
JTextField textField0=new JTextField();
JComboBox cmb_Editor1=new JComboBox();
JComboBox cmb_Editor2=new JComboBox();
JComboBox cmb_Editor3=new JComboBox();
EachRowRenderer rend;
EachRowEditor eee;
/** Creates new form Render */
public Render() {
initComponents ();
rend=new EachRowRenderer();
eee=new EachRowEditor(table);
table.setDefaultRenderer(java.lang.Object.class,rend);
table.setDefaultEditor(java.lang.Object.class,eee);
cmb_Editor3.addItem("Y");
cmb_Editor3.addItem("N");
eee.setEditorAt(0,1,new DefaultCellEditor(cmb_Editor3));
eee.setEditorAt(1,1,new DefaultCellEditor(cmb_Editor3));
eee.setEditorAt(2,1,new DefaultCellEditor(cmb_Editor3));
eee.setEditorAt(0,2,new DefaultCellEditor(new JCheckBox()));
rend.add(0,2,new CheckBoxCellRenderer());
rend.add(0,1,new ComboBoxCellRenderer(cmb_Editor3));
rend.add(1,1,new ComboBoxCellRenderer(cmb_Editor3));
rend.add(2,1,new ComboBoxCellRenderer(cmb_Editor3));
JCheckBox chk=new JCheckBox();
pack ();
public class EachRowEditor implements TableCellEditor {
protected Hashtable editors;
protected TableCellEditor editor, defaultEditor;
JTable table;
public EachRowEditor(JTable table) {
this.table = table;
editors = new Hashtable();
defaultEditor = new DefaultCellEditor(new JTextField());
public void setEditorAt(int row,int column, TableCellEditor editor) {
editors.put(""+row+column,editor);
public Component getTableCellEditorComponent(JTable table,
Object value, boolean isSelected, int row, int column) {
return editor.getTableCellEditorComponent(table,
value, isSelected, row, column);
public Object getCellEditorValue() {
return editor.getCellEditorValue();
public boolean stopCellEditing() {
return editor.stopCellEditing();
public void cancelCellEditing() {
editor.cancelCellEditing();
public boolean isCellEditable(EventObject anEvent) {
selectEditor((MouseEvent)anEvent);
// editor.isCellEditable(anEvent);
return true;
public void addSeperateCellEditorListener(int row,int column,CellEditorListener l) {
editor=(TableCellEditor)editors.get(""+row+column);
editor.addCellEditorListener(l);
public void addCellEditorListener(CellEditorListener l) {
editor.addCellEditorListener(l);
public void removeCellEditorListener(CellEditorListener l) {
editor.removeCellEditorListener(l);
public boolean shouldSelectCell(EventObject anEvent) {
selectEditor((MouseEvent)anEvent);
return editor.shouldSelectCell(anEvent);
protected void selectEditor(MouseEvent e) {
int row;
int column;
if (e == null) {
row = table.getSelectionModel().getAnchorSelectionIndex();
column=table.getSelectionModel().getLeadSelectionIndex();
} else {
row = table.rowAtPoint(e.getPoint());
column=table.columnAtPoint(e.getPoint());
editor = (TableCellEditor)editors.get(""+row+column);
if (editor == null) {
editor = defaultEditor;
public class CheckBoxCellRenderer extends JCheckBox implements TableCellRenderer
CheckBoxCellRenderer() {
setHorizontalAlignment(JLabel.CENTER);
public Component getTableCellRendererComponent(JTable table, Object value,
boolean isSelected, boolean hasFocus,
int row, int column) {
setSelected((value != null && ((Boolean)value).booleanValue()));
setToolTipText("checkbox");
return this;
public class TextFieldCellRenderer extends JTextField implements TableCellRenderer
JTextField textField;
TextFieldCellRenderer(JTextField textField) {
this.textField=textField;
public Component getTableCellRendererComponent(JTable table, Object value,
boolean isSelected, boolean hasFocus,
int row, int column) {
setText((textField.getText() != null) ? textField.getText() : "");
return textField;
public class ComboBoxCellRenderer extends JComboBox implements TableCellRenderer
JComboBox comboBox=null;
ComboBoxCellRenderer(JComboBox comboBox) {
this.comboBox=comboBox;
public Component getTableCellRendererComponent(JTable table, Object value,
boolean isSelected, boolean hasFocus,
int row, int column) {
setSelectedItem(comboBox.getSelectedItem());
return this;
public class EachRowRenderer implements TableCellRenderer {
protected Hashtable renderers;
protected TableCellRenderer renderer, defaultRenderer;
public EachRowRenderer() {
renderers = new Hashtable();
defaultRenderer = new DefaultTableCellRenderer();
public void add(int row,int column ,TableCellRenderer renderer) {
renderers.put(""+row+column,renderer);
public Component getTableCellRendererComponent(JTable table,
Object value, boolean isSelected, boolean hasFocus,
int row, int column) {
renderer = (TableCellRenderer)renderers.get(""+row+column);
if (renderer == null) {
renderer = defaultRenderer;
return renderer.getTableCellRendererComponent(table,
value, isSelected, hasFocus, row, column);
/** This method is called from within the constructor to
* initialize the form.
* WARNING: Do NOT modify this code. The content of this method is
* always regenerated by the FormEditor.
private void initComponents() {
jScrollPane1 = new javax.swing.JScrollPane();
table = new javax.swing.JTable();
addWindowListener(new java.awt.event.WindowAdapter() {
public void windowClosing(java.awt.event.WindowEvent evt) {
exitForm(evt);
table.setModel(new javax.swing.table.DefaultTableModel (
new Object [][] {
{null, null, null, null},
{null, null, null, null},
{null, null, null, null},
{null, null, null, null}
new String [] {
"Title 1", "Title 2", "Title 3", "Title 4"
Class[] types = new Class [] {
java.lang.Object.class, java.lang.Object.class, java.lang.Object.class, java.lang.Object.class
public Class getColumnClass (int columnIndex) {
return types [columnIndex];
jScrollPane1.setViewportView(table);
getContentPane().add(jScrollPane1, java.awt.BorderLayout.CENTER);
/** Exit the Application */
private void exitForm(java.awt.event.WindowEvent evt) {
System.exit (0);
* @param args the command line arguments
public static void main (String args[]) {
new Render ().show ();
// Variables declaration - do not modify
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JTable table;
// End of variables declaration
Please help me.

I ran into the same problem in Java 1.4. The problem is that the JTable is not feeding the initial value to the cell editor. I found the following workaround. You have to override the JTable method prepareEditor() like this:
<CODE>
public Component prepareEditor(TableCellEditor editor, int row, int column) {
Component ret = super.prepareEditor(editor, row, column);
// Translate column to the data model coordinates by using the
// identifier. We'll check only for the JComboBox columns (in
// this example columns 8 and 9).
int col = 0;
String id = (String)getColumnModel().getColumn(column).getIdentifier();
if ( id.equals( tableModel.getColumnName(8) ) )
col = 8;
else if ( id.equals( tableModel.getColumnName(9) ) )
col = 9;
if (col == 8 || col == 9) {
String item = (String)tableModel.getValueAt(row, col);
((JComboBox)((DefaultCellEditor)editor).getComponent()).setSelectedItem( item );
return ret;
</CODE>
You have to translate from table coordinates to table model coordinates in case the user reorders column - if you don't allow this for your table then you won't have to do this.

Combobox getSelectedItem method

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