JCheckbox - ActionListener and ItemListener?

Question

Both ActionListener and ItemListener are used to fire an event with JCheckBox?

So, what\'s the difference between them and in which case one of them is preferred to

Answer 1

I've been testing this myself, and looking at all the answers on this post and I don't think they answer this question very well. I experimented myself in order to get a good answer (code below). You CAN fire either event with both ActionListener and ItemListener 100% of the time when a state is changed in either a radio button or a check box, or any other kind of Swing item I'm assuming since it is type Object. The ONLY difference I can tell between these two listeners is the type of Event Object that gets returned with the listener is different. AND you get a better event type with a checkbox using an ItemListener as opposed to an ActionListener.

The return types of an ActionEvent and an ItemEvent will have different methods stored that may be used when an Event Type gets fired. In the code below the comments show the difference in .get methods for each Class returned Event type.

The code below sets up a simple JPanel with JRadioButtons, JCheckBoxes, and a JLabel display that changes based on button configs. I set all the RadioButtons and CheckBoxes up with both an Action Listener and an Item Listener. Then I wrote the Listener classes below with ActionListener fully commented because I tested it first in this experiment. You will notice that if you add this panel to a frame and display, all radiobuttons and checkboxes always fire regardless of the Listener type, just comment out the methods in one and try the other and vice versa.

Return Type into the implemented methods is the MAIN difference between the two. Both Listeners fire events the same way. Explained a little better in comment above is the reason a checkbox should use an ItemListener over ActionListener due to the Event type that is returned.

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

public class RadioButtonsAndCheckBoxesTest extends JPanel{
JLabel display;
String funny, serious, political;
JCheckBox bold,italic;
JRadioButton funnyQuote, seriousQuote, politicalQuote;
ButtonGroup quotes;

    public RadioButtonsAndCheckBoxesTest(){
        funny = "You are not ugly, you were just born... different";
        serious = "Recommend powdered soap in prison!";
        political = "Trump can eat a little Bernie, but will choke on his     Birdie";

        display = new JLabel(funny);
        Font defaultFont = new Font("Ariel",Font.PLAIN,20);
        display.setFont(defaultFont);

        bold = new JCheckBox("Bold",false);
        bold.setOpaque(false);
        italic = new JCheckBox("Italic",false);
        italic.setOpaque(false);

        //Color itemBackground =

        funnyQuote = new JRadioButton("Funny",true);
        funnyQuote.setOpaque(false);
        seriousQuote = new JRadioButton("Serious");
        seriousQuote.setOpaque(false);
        politicalQuote = new JRadioButton("Political");
        politicalQuote.setOpaque(false);

        quotes = new ButtonGroup();
        quotes.add(funnyQuote);
        quotes.add(seriousQuote);
        quotes.add(politicalQuote);

        JPanel primary = new JPanel();
        primary.setPreferredSize(new Dimension(550, 100));

        Dimension standard = new Dimension(500, 30);

        JPanel radioButtonsPanel = new JPanel();
        radioButtonsPanel.setPreferredSize(standard);
        radioButtonsPanel.setBackground(Color.green);
        radioButtonsPanel.add(funnyQuote);
        radioButtonsPanel.add(seriousQuote);
        radioButtonsPanel.add(politicalQuote);

        JPanel checkBoxPanel = new JPanel();
        checkBoxPanel.setPreferredSize(standard);
        checkBoxPanel.setBackground(Color.green);
        checkBoxPanel.add(bold);
        checkBoxPanel.add(italic);

        primary.add(display);
        primary.add(radioButtonsPanel);
        primary.add(checkBoxPanel);

        //Add Action Listener To test Radio Buttons
        funnyQuote.addActionListener(new ActionListen());
        seriousQuote.addActionListener(new ActionListen());
        politicalQuote.addActionListener(new ActionListen());

        //Add Item Listener to test Radio Buttons
        funnyQuote.addItemListener(new ItemListen());
        seriousQuote.addItemListener(new ItemListen());
        politicalQuote.addItemListener(new ItemListen());

        //Add Action Listener to test Check Boxes
        bold.addActionListener(new ActionListen());
        italic.addActionListener(new ActionListen());

        //Add Item Listener to test Check Boxes
        bold.addItemListener(new ItemListen());
        italic.addItemListener(new ItemListen());

        //adds primary JPanel to this JPanel Object
        add(primary);   
    }

    private class ActionListen implements ActionListener{

        public void actionPerformed(ActionEvent e) {

         /*
         Different Get Methods from  ItemEvent 
         e.getWhen()
         e.getModifiers()
         e.getActionCommand()*/

            /*int font=Font.PLAIN;
            if(bold.isSelected()){
                font += Font.BOLD;
            }
            if(italic.isSelected()){
                font += Font.ITALIC;
            }
            display.setFont(new Font("Ariel",font,20));

            if(funnyQuote.isSelected()){
                display.setText(funny);
            }
            if(seriousQuote.isSelected()){
                display.setText(serious);
            }
            if(politicalQuote.isSelected()){
                display.setText(political);
            }*/
        }
    }
    private class ItemListen implements ItemListener {

        public void itemStateChanged(ItemEvent arg0) {

            /*
            Different Get Methods from ActionEvent
            arg0.getItemSelectable()
            arg0.getStateChange()
            arg0.getItem()*/


            int font=Font.PLAIN;
            if(bold.isSelected()){
                font += Font.BOLD;
            }
            if(italic.isSelected()){
                font += Font.ITALIC;
            }
            display.setFont(new Font("Ariel",font,20));

            if(funnyQuote.isSelected()){
                display.setText(funny);
            }
            if(seriousQuote.isSelected()){
                display.setText(serious);
            }
            if(politicalQuote.isSelected()){
                display.setText(political);
            }

        }

    }
}