How to catch user choice of jradiobutton in jpopupmenu?

Question

I have been able to show a popup menu in my frame and the menu items, a group of radio buttons may be navigated with the arrow keys. When the user presses Enter/Return the popup menu is no longer visible and I assume that it is possible to determine which button was chosen and assign an action.

    private static final JPopupMenu popupSyncTIR = new JPopupMenu();
    popupSyncTIR.setLabel("Sensor Synced to Clock");
    ButtonGroup grpTIR = new ButtonGroup();
    JRadioButtonMenuItem rbTIRMenuItem;
    rbTIRMenuItem = new JRadioButtonMenuItem("Sync TIR-A to clock");
    rbTIRMenuItem.setFont(new Font("Dialog", Font.BOLD, 16));
    grpTIR.add(rbTIRMenuItem);
    popupSyncTIR.add(rbTIRMenuItem);
    rbTIRMenuItem = new JRadioButtonMenuItem("Sync TIR-B to clock");
    rbTIRMenuItem.setFont(new Font("Dialog", Font.BOLD, 16));
    rbTIRMenuItem.setSelected(true);
    grpTIR.add(rbTIRMenuItem);
    popupSyncTIR.add(rbTIRMenuItem);
    rbTIRMenuItem = new JRadioButtonMenuItem("Sync TIR-C to clock");
    rbTIRMenuItem.setFont(new Font("Dialog", Font.BOLD, 16));
    grpTIR.add(rbTIRMenuItem);
    popupSyncTIR.add(rbTIRMenuItem);

I have also implemented key mapping for the whole frame like this:

/**
 * alt-T period synch TIR sensor w/clock
 */
@SuppressWarnings("serial")
private static void registerSyncTIRAction() {
    javax.swing.Action tirSync = new AbstractAction() {
        @Override
        public void actionPerformed(ActionEvent ae) {
            setTIRSensorSync();
        }
    };
    KeyStroke keyStroke = KeyStroke.getKeyStroke(KeyEvent.VK_T,
            java.awt.event.InputEvent.ALT_DOWN_MASK);
    ((JComponent) contentPanel).getActionMap().put("TirSync", tirSync);
    ((JComponent) contentPanel).getInputMap(
            JComponent.WHEN_IN_FOCUSED_WINDOW).put(keyStroke, "TirSync");

}

/** 
 * Show the TIR popup
 */
private static void setTIRSensorSync() {
    popupSyncTIR.show(pnlTIR, 10, 10); 
}

How do I determine what radio button was selected before the user pressed Enter?

Answer 1

Just the same as you would with radioButtons which are not in a menu :-) Use Actions:

Action actionA = new AbstractAction("Synch A to clock") {

    @Override
    public void actionPerformed(ActionEvent e) {
        // do stuff A
    }
};
JRadioButtonMenuItem buttonA = new JRadioButtonMenuItem(actionA);
Action actionB = new AbstractAction("Synch B to clock") {

    @Override
    public void actionPerformed(ActionEvent e) {
        // do stuff B
    }
};
JRadioButtonMenuItem buttonB = new JRadioButtonItem(actionB);
ButtonGroup ... // add buttons to group
JPopupMenu ... // add buttons to menu