How can I utilize a secondary class to handle my events?

Question

I've created two separate classes whereas I have instantiated my menu bar, and a second class to handle the events; since I do have a lot of options on the menu bar I'd like to handle.

I have the menu bar and it's structure all set up, now the next step is to handle the events when the user clicks an option on the menu bar.

Here's a snippet of two items from my main menu-bar class:

    JMenuItem addOrangeItem = new JMenuItem("Orange");
    addOrangeItem.addActionListener(new MenuActionListener().orangeActionPerformed(e));

    JMenuItem addAppleItem = new JMenuItem("Apple");
    addAppleItem.addActionListener(new MenuActionListener().appleActionPerformed(e));

Here's my event handling class:

public class MenuActionListener implements ActionListener {

    public void orangeActionPerformed(ActionEvent e) {
    }
    @Override
    public void actionPerformed(ActionEvent e) {
        System.out.println("I have chosen an orange!");
    }


    public void appleActionPerformed(ActionEvent e) {
    }
    @Override
    public void actionPerformed(ActionEvent e) {
        System.out.println("I have chosen an apple!");
    }
}

The problem lies on this line of code in my main menu-bar class:

addAppleItem.addActionListener(new MenuActionListener().appleActionPerformed(e)); whereas the e for my ActionEvent is underlined as red and I'm not sure what to do to get it working.

The goal of my code is to select the Apple/orange item/s and my event handling class will then return some code.

My question is how can I edit the above line of code so that I can then handle my menu bar items correctly?

If you require any more information, please let me know and I will get right onto that.

Any help is greatly appreciated, thank you.

Answer 1

This is an invalid syntax :addActionListener(new MenuActionListener().orangeActionPerformed(e)) .

addActionListener wants an ActionListener object, not void (which is the result of new MenuActionListener().orangeActionPerformed(e)), and also e is an unknown variable here.

This will work : addActionListener(new MenuActionListener()) , but since you need different actions depending on the pressed item, you may use the action command system :

Set an action command on your JMenuItem (also note that one instance of ActionListener is enough for both buttons) :

ActionListener listener = new MenuActionListener();

JMenuItem addOrangeItem = new JMenuItem("Orange");
addOrangeItem.setActionCommand("orange");// set action command
addOrangeItem.addActionListener(listener);

JMenuItem addAppleItem = new JMenuItem("Apple");
addAppleItem.setActionCommand("apple");// set action command
addAppleItem.addActionListener(listener);

Then retrieve the action command in the listener (in actionPerformed), and decide what to do :

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

    public class MenuActionListener implements ActionListener {

        public void orangeActionPerformed() {
            System.out.println("I have chosen an orange!");
        }

        public void appleActionPerformed() {

            System.out.println("I have chosen an apple!");

        }

        @Override
        public void actionPerformed(final ActionEvent e) {

            String command = e.getActionCommand();

            switch (command) {

            case "orange":
                orangeActionPerformed();
                break;
            case "apple":
                appleActionPerformed();
                break;
            default:

            }

        }
    }

Note that setActionCommand is a method from AbstractButton, and also works for JButton for instance.