public class CalculatorGUI extends JFrame implements ActionListener {

    // Number buttons
    JButton bone = new JButton("1");
    JButton btwo = new JButton("2");


    // Operation buttons
    JButton bplus = new JButton("+");


    // Reset Buttons
    JButton bac = new JButton("AC");
    JButton bc = new JButton("C");

    // Textfield for operations and results
    JTextField mathop = new JTextField();

    CalculatorCtrl ctrl;

    CalculatorGUI(String s, CalculatorCtrl c) {
        super(s);
        getContentPane().setLayout(new BorderLayout());

        // Panel for the numbers (0-9)


        // Panel for aritmethic operations

        mathop.setHorizontalAlignment(JTextField.RIGHT);
        getContentPane().add(mathop, BorderLayout.NORTH);

        ctrl = c;

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        pack();
        setResizable(false);
        setVisible(true);
    }