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

class TrippButtonListener implements ActionListener {
    public void actionPerformed(ActionEvent event) {
        System.out.println("Tripp!");
    }
} // class TrippButtonListener

public class BoringWindow {
    private int bwx = 1;

    private class TrappButtonListener implements ActionListener {
        public void actionPerformed(ActionEvent event) {
            System.out.println("Trapp!");
            System.out.println("bwx = " + bwx);
        }
    } // class TrappButtonListener

    public BoringWindow() {
        int kx = 2;
        final int fkx = 3;

        class TrullButtonListener implements ActionListener {
            public void actionPerformed(ActionEvent event) {
                System.out.println("Trull!");
                System.out.println("bwx = " + bwx);
                // Ger kompileringsfel
                // local variable kx is accessed from within inner class; needs to be declared final
                // System.out.println("kx = " + kx);
                System.out.println("fkx = " + fkx);
            }
        } // class TrullButtonListener

        JFrame frame = new JFrame("Ett tråkigt fönster");
        frame.setSize(350, 50);

        Container cp = frame.getContentPane();
        cp.setLayout(new GridLayout(1, 4));

        JButton trippknapp = new JButton("Tripp!");
        JButton trappknapp = new JButton("Trapp!");
        JButton trullknapp = new JButton("Trull!");
        JButton hejsanknapp = new JButton("Hejsan!");

        cp.add(trippknapp);
        cp.add(trappknapp);
        cp.add(trullknapp);
        cp.add(hejsanknapp);

        trippknapp.addActionListener(new TrippButtonListener());
        trappknapp.addActionListener(new TrappButtonListener());
        trullknapp.addActionListener(new TrullButtonListener());
        hejsanknapp.addActionListener(new ActionListener() {
                public void actionPerformed(ActionEvent event) {
                    System.out.println("Hejsan!");
                    System.out.println("bwx = " + bwx);
                    // Ger kompileringsfel
                    // local variable kx is accessed from within inner class; needs to be declared final
                    // System.out.println("kx = " + kx);
                    System.out.println("fkx = " + fkx);
                }
            });

        frame.setVisible(true);
    } // BoringWindow

    public static void main(String[] args) {
        final BoringWindow b = new BoringWindow();
        int mx = 4;
        final int fmx = 5;

        class UnusedButtonListener implements ActionListener {
            public void actionPerformed(ActionEvent event) {
                System.out.println("Impossible!");
                // Ger kompileringsfel
                // non-static variable bwx cannot be referenced from a static context
                // System.out.println("bwx = " + bwx);
                System.out.println("b.bwx = " + b.bwx);
                // Ger kompileringsfel
                // local variable mx is accessed from within inner class; needs to be declared final
                // System.out.println("mx = " + mx);
                System.out.println("fmx = " + fmx);
            }
        } // class TrullButtonListener

        // Ger kompileringsfel
        // non-static variable this cannot be referenced from a static context
        // new TrappButtonListener();

        new TrippButtonListener();

        // Ger kompileringsfel
        // cannot resolve symbol
        // new TrullButtonListener();

        new UnusedButtonListener();
    } // main
} // class BoringWindow