Visualisierung

import java.awt.BorderLayout;
import java.awt.EventQueue;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JTextField;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;


public class Visualisierung extends JFrame {

    private JPanel contentPane;
    private JTextField textField;

    private double ZahlEins;
    private double ZahlZwei;

    private boolean hatZahlEins;
    private boolean hatZahlZwei;

    char Rechenart;
    boolean hatRechenart;


    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    Visualisierung frame = new Visualisierung();
                    frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the frame.
     */
    public Visualisierung() {
        setTitle("Bujkoffer\u00B4s Rechner");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 400, 314);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        contentPane.setLayout(new BorderLayout(0, 0));
        setContentPane(contentPane);

        JPanel panel = new JPanel();
        contentPane.add(panel, BorderLayout.CENTER);
        panel.setLayout(null);

        JButton btnNewButton_1 = new JButton("2");
        btnNewButton_1.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                eingabeZahl(2);
            }
        });
        btnNewButton_1.setBounds(84, 180, 47, 23);
        panel.add(btnNewButton_1);

        JButton btnNewButton = new JButton("8");
        btnNewButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                eingabeZahl(8);
            }
        });
        btnNewButton.setBounds(84, 112, 47, 23);
        panel.add(btnNewButton);

        JButton btnNewButton_2 = new JButton("1");
        btnNewButton_2.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                eingabeZahl(1);
            }
        });
        btnNewButton_2.setBounds(26, 180, 48, 23);
        panel.add(btnNewButton_2);

        JButton btnNewButton_3 = new JButton("3");
        btnNewButton_3.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                eingabeZahl(3);
            }
        });
        btnNewButton_3.setBounds(141, 180, 44, 23);
        panel.add(btnNewButton_3);


        JButton btnNewButton_4 = new JButton("6");
        btnNewButton_4.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                eingabeZahl(6);
            }
        });
        btnNewButton_4.setBounds(141, 146, 44, 23);
        panel.add(btnNewButton_4);

        JButton btnNewButton_5 = new JButton("5");
        btnNewButton_5.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                eingabeZahl(5);
            }
        });
        btnNewButton_5.setBounds(84, 146, 47, 23);
        panel.add(btnNewButton_5);

        JButton btnNewButton_6 = new JButton("9");
        btnNewButton_6.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                eingabeZahl(9);
            }
        });
        btnNewButton_6.setBounds(141, 112, 44, 23);
        panel.add(btnNewButton_6);

        JButton btnNewButton_7 = new JButton("4");
        btnNewButton_7.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                eingabeZahl(4);
            }

        });
        btnNewButton_7.setBounds(26, 146, 48, 23);
        panel.add(btnNewButton_7);

        JButton btnNewButton_8 = new JButton("0");
        btnNewButton_8.setBounds(26, 220, 159, 23);
        panel.add(btnNewButton_8);

        JButton btnNewButton_9 = new JButton("7");
        btnNewButton_9.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                eingabeZahl(7);
            }
        });
        btnNewButton_9.setBounds(26, 112, 48, 23);
        panel.add(btnNewButton_9);

        JButton btnNewButton_10 = new JButton("/");
        btnNewButton_10.setBounds(214, 220, 51, 23);
        panel.add(btnNewButton_10);

        JButton btnNewButton_11 = new JButton("*");
        btnNewButton_11.setBounds(214, 180, 51, 23);
        panel.add(btnNewButton_11);

        JButton btnNewButton_12 = new JButton("-");
        btnNewButton_12.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
            }
        });
        btnNewButton_12.setBounds(214, 146, 51, 23);
        panel.add(btnNewButton_12);

        JButton button = new JButton("+");
        button.setBounds(214, 112, 51, 23);
        panel.add(button);

        JButton button_1 = new JButton("=");
        button_1.setBounds(275, 220, 89, 23);
        panel.add(button_1);

        textField = new JTextField();
        textField.setBounds(100, 26, 172, 53);
        panel.add(textField);
        textField.setColumns(10);
    }

    public void eingabeRechenart (char rechenart) {
        if(!hatRechenart) {
            Rechenart = rechenart;
        }
    }

    public void eingabeZahl (double zahl) {

        if(!hatZahlEins) {
            ZahlEins = zahl;
            hatZahlEins = true;
        } else if(!hatZahlZwei) {
            ZahlZwei = zahl;
            hatZahlZwei = true;
        }


    }
}