JMenu ActionListener

Question

I was wondering if can you test to see if a JMenu (not JMenuItem) has been clicked. I tried adding an ActionListener to it but it doesn't seem to recognize it. I just need it to preform an action when the JMenu button is pressed so that I can change the JMenuItems for that menu befor it opens. All work arrounds to get this result are welcome too!

Thanks

Solution

• for JMenu use MenuListener

code

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;

public class ActionExample {

    public ActionExample() {

        JMenu menu = new JMenu("Menu");
        menu.setMnemonic(KeyEvent.VK_M);
        menu.addMenuListener(new SampleMenuListener());
        JMenu menu1 = new JMenu("Tool");
        menu1.setMnemonic(KeyEvent.VK_T);
        menu1.addMenuListener(new SampleMenuListener());
        JFrame f = new JFrame("ActionExample");
        JMenuBar mb = new JMenuBar();
        mb.add(menu);
        mb.add(menu1);
        f.setJMenuBar(mb);
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                ActionExample actionExample = new ActionExample();
            }
        });
    }
}

class SampleMenuListener implements MenuListener {

    @Override
    public void menuSelected(MenuEvent e) {
        System.out.println("menuSelected");
    }

    @Override
    public void menuDeselected(MenuEvent e) {
        System.out.println("menuDeselected");
    }

    @Override
    public void menuCanceled(MenuEvent e) {
        System.out.println("menuCanceled");
    }
}

• for JMenuItem use only ButtonModel

Comments

[assylias]

Have you tried addMenuListener?

[clankfan1]

No I'm using addActionListener right now but to add that I run into some problems, shouldn't actionListener work aswell though?

[Hovercraft Full Of Eels]

Why change the menu items on JMenu click? Why not change it before the click? What is your "use case" here?

[clankfan1]

mre, that only works for JMenuItems I need a listener for a JMenu

[clankfan1]

Hovercraft, I'm using it to determine whether or not certain JMenuItems are enabled and I thought it would be an easy way to test it without using threads...

[Andrew Thompson]

"determine whether or not certain JMenuItems are enabled" setEnabled(boolean) is not enough?

[Hovercraft Full Of Eels]

I'm still not quite sure what your goal is. You can trap Menu clicks with a ChangeListener, however the rationale has a funny smell to me.

[Hummeling Engineering BV]

In this case, where we're only overriding a single method, use MouseAdapter for cleaner code.

[Hummeling Engineering BV]

We can add an ActionListener to JMenu, but it just doesn't have any effect. JMenu opens its child JMenus and JMenuItems when the mouse hovers over it. I think the question is about the extra functionality to perform an action when clicking on the JMenu.