Java Swing Tutorial - Java JMenuItem(Action a) Constructor

Syntax

JMenuItem(Action a) constructor from JMenuItem has the following syntax.

public JMenuItem(Action a)

Example

In the following code shows how to use JMenuItem.JMenuItem(Action a) constructor.

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
//from  w  ww .ja  v a2  s  .  c om
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JToolBar;

public class Main {

  public static void main(String args[]) {
    JFrame frame = new JFrame("Action Sample");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    final Action printAction = new PrintHelloAction();

    JMenuBar menuBar = new JMenuBar();
    JMenu menu = new JMenu("File");
    menuBar.add(menu);
    menu.add(new JMenuItem(printAction));

    JToolBar toolbar = new JToolBar();
    toolbar.add(new JButton(printAction));

    JButton enableButton = new JButton("Enable");
    ActionListener enableActionListener = new ActionListener() {
      public void actionPerformed(ActionEvent actionEvent) {
        printAction.setEnabled(true);
      }
    };
    enableButton.addActionListener(enableActionListener);

    JButton disableButton = new JButton("Disable");
    ActionListener disableActionListener = new ActionListener() {
      public void actionPerformed(ActionEvent actionEvent) {
        printAction.setEnabled(false);
      }
    };
    disableButton.addActionListener(disableActionListener);

    JButton relabelButton = new JButton("Relabel");
    ActionListener relabelActionListener = new ActionListener() {
      public void actionPerformed(ActionEvent actionEvent) {
        printAction.putValue(Action.NAME, "Hello, World");
      }
    };
    relabelButton.addActionListener(relabelActionListener);

    JPanel buttonPanel = new JPanel();
    buttonPanel.add(enableButton);
    buttonPanel.add(disableButton);
    buttonPanel.add(relabelButton);

    frame.setJMenuBar(menuBar);

    frame.add(toolbar, BorderLayout.SOUTH);
    frame.add(buttonPanel, BorderLayout.NORTH);
    frame.setSize(300, 200);
    frame.setVisible(true);

  }

}

class PrintHelloAction extends AbstractAction {

  PrintHelloAction() {
    super("Print");
    putValue(Action.SHORT_DESCRIPTION, "Hello, World");
  }

  public void actionPerformed(ActionEvent actionEvent) {
    System.out.println("Hello, World");
  }
}