Test_Disable_JFrame

import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;

import javax.swing.*;


public class MainWindow extends JFrame{

    private JButton button1;
    private JTextField textField;

    private JMenuBar menuBar;

    private JPanel contentPane;

    public MainWindow () {
        super("Main window");
        initComponents();
        }

    private void initComponents(){
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        contentPane = new JPanel(new GridLayout(1,2));
        contentPane.setOpaque(true);

        //We add one button
        initButton1();
        contentPane.add(button1);

        //We add another one button
        textField = new JTextField("Enable");
        contentPane.add(textField);

        //We add a MenuBar
        initMenuBar();
        this.setJMenuBar(menuBar);

        //Now, we can add the contentPane to the JFrame
        this.setContentPane(contentPane);
    }

    private void initButton1() {
        button1 = new JButton("Disable Frame");
        button1.addActionListener(new ActionListener (){
            public void actionPerformed(ActionEvent arg0) {
                MainWindow.this.setEnabled(false);
                MainWindow.this.textField.setText("Disabled");
                // MainWindow.this.contentPane.setEnabled(false); //This don't disable any component.
                MainWindow.this.menuBar.setEnabled(true); //This doesn't allow to use menuBar
                }
            }
        );
    }

    private void initMenuBar(){
        menuBar = new JMenuBar();
        JMenu file = new JMenu("File");

        file.add(new JSeparator());

        JMenuItem quit = new JMenuItem("QUIT",KeyEvent.VK_Q);
        quit.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {System.exit(0);}}
        );
        file.add(quit);

        menuBar.add(file);

    }

       /**
     * Create the GUI and show it.  For thread safety,
     * this method should be invoked from the
     * event-dispatching thread.
     */
    private static void createAndShowGUI() {
        //Create and set up the window.
        MainWindow test = new MainWindow();

        //Display the window.
        test.pack();
        test.setVisible(true);
    }

    public static void main(String[] args) {
        //Schedule a job for the event-dispatching thread:
        //creating and showing this application's GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }
}