import java.awt.*;
import java.awt.event.*;
import java.time.LocalTime;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

class GridEksempel {

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

        JPanel panel = new JPanel();
        vindu.add(panel);
        lagGridKnaper(panel);

        vindu.pack();
        vindu.setVisible(true);
    }
    
    public static void lagGridKnaper(JPanel panel){
        panel.setLayout(new GridLayout(2,3));
        int teller = 1;
        for(int i = 0; i < 2; i++){
            for(int j = 0; j < 3; j++){
                panel.add(new GridKnapp(""+teller++));
            }
        }
    }
}

class GridKnapp extends JButton{
    private String tall;

    public GridKnapp(String tall){
        super(tall);
        this.tall = tall;
        initGUI();
    }

    class EndreKnappTekst implements ActionListener{
        
        @Override
        public void actionPerformed(ActionEvent e){
            if(getText().equals(tall)){
                setText(":)");
            }else{
                setText(tall);
            }
        }
    }

    public void initGUI(){
        addActionListener(new EndreKnappTekst());
    }
}