Mega Code Archive
Listening to JRadioButton Events with an ItemListener
<![CDATA[
import java.awt.GridLayout;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import javax.swing.AbstractButton;
import javax.swing.ButtonGroup;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
public class JRadioButtonItemListener {
public static void main(String args[]) {
JFrame frame = new JFrame("Grouping Example");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel panel = new JPanel(new GridLayout(0, 1));
ButtonGroup group = new ButtonGroup();
JRadioButton aRadioButton = new JRadioButton("A");
JRadioButton bRadioButton = new JRadioButton("B");
ItemListener itemListener = new ItemListener() {
String lastSelected;
public void itemStateChanged(ItemEvent itemEvent) {
AbstractButton aButton = (AbstractButton)itemEvent.getSource();
int state = itemEvent.getStateChange();
String label = aButton.getText();
String msgStart;
if (state == ItemEvent.SELECTED) {
if (label.equals(lastSelected)) {
msgStart = "Reselected -> ";
} else {
msgStart = "Selected -> ";
}
lastSelected = label;
} else {
msgStart = "Deselected -> ";
}
System.out.println(msgStart + label);
}
};
panel.add(aRadioButton);
group.add(aRadioButton);
panel.add(bRadioButton);
group.add(bRadioButton);
aRadioButton.addItemListener(itemListener);
bRadioButton.addItemListener(itemListener);
frame.add(panel);
frame.setSize(300, 200);
frame.setVisible(true);
}
}
]]>