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

public class ST4 extends JFrame implements ActionListener{
    public ST4 () {
        JPanel pane = new JPanel();
        JButton knapp1 = new JButton ("Blip");
        JButton knapp2 = new JButton ("Blup");
        knapp1.addActionListener(this);
        knapp2.addActionListener(this);
        pane.add(knapp1);
        pane.add(knapp2);
        add(pane);

        setBounds(100,100,300,200);
	setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        vilkenTrad("Konstruktor:");
        setVisible(true);

    }
    
    public void actionPerformed(ActionEvent event) {
        System.out.println(((JButton)event.getSource()).getText());
        vilkenTrad("Action: ");
    }

    public static void vilkenTrad(String s) {
        if (javax.swing.SwingUtilities.isEventDispatchThread()) {
            System.out.println(s+" Handelsetrad");
        } else {
            System.out.println(s+" Huvudtrad");
        }
    }
                
    public static void main(String[] arg) {
        SwingUtilities.invokeLater(new Runnable() {
                public void run() {
                    ST4 frame = new ST4();
                    vilkenTrad("Run: ");            
                }
            });
        vilkenTrad("Main: ");            
    }
}