Miscellany

package huiswerk3;import javax.swing.*;import java.awt.*;import java.awt.event.*;/** * * @author Martijn */public class Knoppen extends JPanel {    private JButton[] buttons = new JButton[16];        public Knoppen(){        KnopHandler kh = new KnopHandler();        for(int i = 0; i < buttons.length; i++){            buttons[i] = new JButton();            buttons[i].setText("" + (i));            if(i == 10){                buttons[i].setText("C");            }            if(i == 11){                buttons[i].setText("/");            }            if(i == 12){                buttons[i].setText("+");            }            if(i == 13){                buttons[i].setText("-");            }            if(i == 14){                buttons[i].setText("*");            }            if(i == 15){                buttons[i].setText("=");            }           add(buttons[i]);           buttons[i].addActionListener(kh);        }          setLayout( new GridLayout(4,5));     }    public class KnopHandler implements ActionListener{        private Rekenmachine rekenmachine;            public void actionPerformed(ActionEvent e){                Rekenmachine r = new Rekenmachine();                if(e.getSource() == buttons[1]){                    r.setTextVak();                }                if(e.getSource() == buttons[2]){                    System.out.println("bla");                }            }    }}