import java.awt.*;
import java.awt.event.*;

import javax.swing.*;
import javax.swing.border.Border;

class Knapperi {
    public static void main(String[] args) {
        JFrame vindu = new JFrame();
        vindu.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        KnappeGrid knappegrid = new KnappeGrid(5,5);
        knappegrid.initGUI();
        vindu.add(knappegrid);
        vindu.setMinimumSize(new Dimension(500,500));


        vindu.pack();
        vindu.setVisible(true);
    }


    static class KnappeGrid extends JPanel {
        GridLayout layout;
        int rad,kol;

        Knapp[][] knapper;
        Knapp borderKnapp = null;
        Border knappBor;

        KnappeGrid(int r, int k){
            this.rad = r;
            this.kol = k;
            layout = new GridLayout(rad,kol);


            knapper = new Knapp[rad][kol];

        }
        
        void initGUI(){
            this.setLayout(layout);
            for (int i = 0; i < rad; i++) {
                for (int j = 0; j < kol; j++) {

                    Knapp knapp = new Knapp("Knapp");
                    this.add(knapp);

                    knapper[i][j] = knapp;
                    // Alle mulige koordinater for naboer
                    int[][] koord = new int[4][2];
                    koord[0][0] = i + 1;
                    koord[0][1] = j;

                    koord[1][0] = i - 1;
                    koord[1][1] = j;

                    koord[2][0] = i;
                    koord[2][1] = j + 1;

                    koord[3][0] = i;
                    koord[3][1] = j - 1;

                    

                    knapp.addActionListener(new ActionListener(){
                    

                        @Override
                        public void actionPerformed(ActionEvent e) {
                            // Gå gjennom nabo array
                            for (int l = 0; l < koord.length; l++) {
                                // Sjekke utenfor array
                                if (!(koord[l][1] < 0 || koord[l][0] < 0 
                                    || koord[l][0] >= rad || koord[l][1] >= kol)) {

                                    // Hente ut fra arrayet
                                    knapper[koord[l][0]][koord[l][1]].farg();
                                }
                            }


                            // Sette border
                            if (borderKnapp != null){
                                borderKnapp.setBorder(knappBor);
                                
                            }
                            borderKnapp = knapp;
                            knappBor = borderKnapp.getBorder();
                            knapp.setBorder(BorderFactory.createLineBorder(Color.RED));
                        }

                    });

                    
                }
            }
        }

        



        class Knapp extends JButton {

        int farge = 0;

            Knapp(String text){
                super(text);
            }

            void farg(){
                // Mulig farge ikke funker på mac
                // Prøv med setOpaque(true);

                if (farge == 0) {
                    // setForeground(Color.RED);
                    setBackground(Color.RED);
                    // setOpaque(true);

                    farge++;
                } else if (farge == 1){
                    // setForeground(Color.BLUE);
                    setBackground(Color.BLUE);
                    // setOpaque(true);
                    farge++;
                } else {
                    // setForeground(Color.BLACK);
                    setBackground(Color.WHITE);
                    // setOpaque(false);

                    farge = 0;
                }
            }


        }
    }
}