Multiple JRadioButtons in a JTable cell

Question

I have this code that works, but I want to make it so only a single click is require to change the radio buttons in the cell. Right now it takes a double click.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;
import javax.swing.event.*;
* @version 1.2 08/13/99
public class JRadioButtonTableExample2 extends JFrame {
  public JRadioButtonTableExample2(){
    super( "JRadioButtonTable Example" );
        String[] columnHeader = {"Questions","Answer"};
         Object[][] o = new Object[50][2];
         DefaultTableModel dm = new DefaultTableModel();
         dm.setDataVector(o,columnHeader);
    JTable table = new JTable(dm);
    String[] answer = {"A","B","C"};
    table.getColumn("Answer").setCellRenderer(
      new RadioButtonRenderer(answer)
    table.getColumn("Answer").setCellEditor(
      new RadioButtonEditor(new JCheckBox(),
                            new RadioButtonPanel(answer))
    JScrollPane scroll = new JScrollPane(table);
    getContentPane().add( scroll );
  // Cell base
  class RadioButtonPanel extends JPanel {
    JRadioButton[] buttons;
    RadioButtonPanel(String[] str) {
      setLayout(new BoxLayout(this, BoxLayout.X_AXIS));
      buttons = new JRadioButton[str.length];
      for (int i=0; i<buttons.length; i++) {
        buttons[i] = new JRadioButton(str);
buttons[i].setFocusPainted(false);
add(buttons[i]);
public void setSelectedIndex(int index) {
for (int i=0;i<buttons.length;i++) {
buttons[i].setSelected(i == index);
public int getSelectedIndex() {
for (int i=0; i<buttons.length; i++) {
if (buttons[i].isSelected()) {
return i;
return -1;
public JRadioButton[] getButtons() {
return buttons;
class RadioButtonRenderer extends RadioButtonPanel
implements TableCellRenderer {   
RadioButtonRenderer(String[] strs) {
super(strs);
public Component getTableCellRendererComponent(JTable table, Object value,
boolean isSelected, boolean hasFocus, int row, int column) {
if (value instanceof Integer) {
setSelectedIndex(((Integer)value).intValue());
return this;
class RadioButtonEditor extends DefaultCellEditor
implements ItemListener {
RadioButtonPanel panel;
public RadioButtonEditor(JCheckBox checkBox,RadioButtonPanel panel) {
super(checkBox);
this.panel = panel;
ButtonGroup buttonGroup = new ButtonGroup();
JRadioButton[] buttons = panel.getButtons();
for (int i=0; i<buttons.length; i++) {
buttonGroup.add(buttons[i]);
buttons[i].addItemListener(this);
public Component getTableCellEditorComponent(JTable table, Object value,
boolean isSelected, int row, int column) {
if (value instanceof Integer) {
panel.setSelectedIndex(((Integer)value).intValue());
return panel;
public Object getCellEditorValue() {
return new Integer(panel.getSelectedIndex());
public void itemStateChanged(ItemEvent e) {
super.fireEditingStopped();
public static void main(String[] args) {
JRadioButtonTableExample2 frame = new JRadioButtonTableExample2();
frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
frame.setSize( 230, 140 );
frame.setVisible(true);

Answer 1

It looks to me like the problem is that the renderer is interfering with the editor. When the editor is invoked, something in jtable is rerendering the other items. This is causing a flood of change events to be fired. I'm not sure how you would fix this. The first thing that occurred to me was to make a separate set of buttons for the renderer vs the editor. I don't have time to try it right now.