How to deselect already selected JRadioButton by clicking on it

Question

Let's say we are having some JRadioButtons which belongs to same ButtonGroup, when user clicks on a JRadioButton it got selected. I want to add a feature that when user click on already selected JRadioButton, it gets deselected, that is whole ButtonGroup will have no JRadioButton selected. I already searched which leads me hint to use, ButtonGroup method, clearSelection. but problem is that when user clicks on already selected JRadioButton, it is not generating any ItemStateChangeEvent, which is generating by clicking on other unselected JRadioButtons.

Answer 1

Or, as an alternate approach, override ButtonGroup#setSelected(...):

import java.awt.*;
import java.util.Arrays;
import javax.swing.*;

public class Test2 {
  public JComponent makeUI() {
    JPanel p = new JPanel(new GridLayout(2, 1));
      p.add(makePanel("Default ButtonGroup", new ButtonGroup()));
      p.add(makePanel("Custom ButtonGroup", new ButtonGroup() {
          private ButtonModel prevModel;
          private boolean isAdjusting = false;
          @Override public void setSelected(ButtonModel m, boolean b) {
              if (isAdjusting) {
                  return;
              }
              if (m.equals(prevModel)) {
                  isAdjusting = true;
                  clearSelection();
                  isAdjusting = false;
              } else {
                  super.setSelected(m, b);
              }
              prevModel = getSelection();
          }
      }));
    return p;
  }
  private JComponent makePanel(String title, ButtonGroup g) {
    JPanel p = new JPanel();
    p.setBorder(BorderFactory.createTitledBorder(title));
    for (String s: Arrays.asList("aaa", "bbb", "ccc")) {
      AbstractButton r = new JRadioButton(s);
      //AbstractButton r = new JToggleButton(s);
      p.add(r);
      g.add(r);
    }
    return p;
  }
  public static void main(String... args) {
    EventQueue.invokeLater(() -> {
      JFrame f = new JFrame();
      f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
      f.getContentPane().add(new Test2().makeUI());
      f.setSize(320, 240);
      f.setLocationRelativeTo(null);
      f.setVisible(true);
    });
  }
}