public void actionPerformed(ActionEvent e) {
   calc = (Calculator) e.getSource();
   antwoordVeld.setText(
       "<["
           + calc.getBase().getName()
           + ","
           + calc.getFormat().getName()
           + ","
           + calc.firstOperand()
           + ", "
           + calc.secondOperand()
           + "] >");
 }
 public CalculatorView() {
   this.add(antwoordVeld);
   antwoordVeld.setText("<[dec, fixed, 0.0, 0.0]>");
 }