MainFrame (Swing)

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

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTextArea;

public class MainFrame extends JFrame{

    // Variables-components
    private TextPanel textPanel;
    //private JButton btn;
    private Toolbar toolbar;
    private FormPanel formPanel;

    // Constructor
    public MainFrame() {
        super("Hello World!");                              // Create a JFrame named "Hello World!"

        // 1. Layout Manager
        setLayout(new BorderLayout());                      // Orizw me ti eidous Layout tha doulepsw
        textPanel = new TextPanel();                        // Initialize textArea
        //btn = new JButton("Click Me!");                       // Initialize btn
        toolbar = new Toolbar();
        formPanel = new FormPanel();

        // 2. Add the components
        add(textPanel, BorderLayout.CENTER);                    // Add the components
        //add(btn, BorderLayout.SOUTH);                     // 2nd argument = position
        add(toolbar, BorderLayout.NORTH);
        add(formPanel, BorderLayout.WEST);

        toolbar.setStringListener(new StringListener() {
            public void textEmitted(String text) {
                System.out.println(text);
                textPanel.appendText(text);
            }
        });


        // 3. When I click on btn, I want the message "Hello" to be written in textArea
        /*
        btn.addActionListener(new ActionListener() {        // Add the unimplemented function of this class

            //@Override
            public void actionPerformed(ActionEvent arg0) {
                textPanel.appendText("Hello\n");

            }

        });
        */

        // 4. Basic operations
        setSize(600, 600);                                  // Set dimensions to my window
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);     // Gia na kleinei to parathyro otan pataw to "X"
        setVisible(true);                                   // To make my window visible (it is invisible by default)
    }
}