import java.awt.*;

import java.awt.event.*;

import javax.swing.*;

import javax.swing.event.*;



public class Calculator extends JFrame {

    private JTextField displayField;       

    private boolean   angkaPertama = true;     

    private String    operator  = "=";       

    private OtakKalkulator logik = new OtakKalkulator(); 

 public static void main(String args[]){

 

    Calculator window = new Calculator();

    window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

 window.setSize(800,800);

    window.setVisible(true);

    }



       public Calculator()

       {

    super("Calculator");

    

    displayField = new JTextField("0",20);

    displayField.setHorizontalAlignment(JTextField.LEFT);

   

        JPanel buttonPanel = new JPanel();

        buttonPanel.setLayout(new GridLayout(4,3));

  ActionListener numListener = new NumListener();

  ActionListener clearListener = new ClearListener();

  ActionListener hapusListener = new HapusListener();

  JButton tombol0 = new JButton("0");

  JButton tombol1 = new JButton("1");

  JButton tombol2 = new JButton("2");

  JButton tombol3 = new JButton("3");

  JButton tombol4 = new JButton("4");

  JButton tombol5 = new JButton("5");

  JButton tombol6 = new JButton("6");

  JButton tombol7 = new JButton("7");

  JButton tombol8 = new JButton("8");

  JButton tombolHapusSemua = new JButton("CE");

  JButton tombol9 = new JButton("9");

  JButton tombolHapus = new JButton("C");

  buttonPanel.add(tombol1);

  tombol1.addActionListener(numListener);

  buttonPanel.add(tombol2);

  tombol2.addActionListener(numListener);

  buttonPanel.add(tombol3);

  tombol3.addActionListener(numListener);

  buttonPanel.add(tombol4);

  tombol4.addActionListener(numListener);

  buttonPanel.add(tombol5);

  tombol5.addActionListener(numListener);

  buttonPanel.add(tombol6);

  tombol6.addActionListener(numListener);

  buttonPanel.add(tombol7);

  tombol7.addActionListener(numListener);

  buttonPanel.add(tombol8);

  tombol8.addActionListener(numListener);

  buttonPanel.add(tombol9);

  tombol9.addActionListener(numListener);

  buttonPanel.add(tombolHapusSemua);

  tombolHapusSemua.addActionListener(clearListener);

  buttonPanel.add(tombol0);

  tombolHapus.addActionListener(hapusListener);

  buttonPanel.add(tombolHapus);

  

  ActionListener opListener = new OpListener();



        JPanel opPanel = new JPanel();

        opPanel.setLayout(new GridLayout(5,1));

  JButton plus = new JButton("+");

  JButton minus = new JButton("-");

  JButton kali = new JButton("*");

  JButton bagi = new JButton("/");

  JButton samadengan = new JButton("=");

  opPanel.add(plus);

  plus.addActionListener(opListener);

  opPanel.add(minus);

  minus.addActionListener(opListener);

  opPanel.add(kali);

  kali.addActionListener(opListener);

  opPanel.add(bagi);

  bagi.addActionListener(opListener);

  opPanel.add(samadengan);

  samadengan.addActionListener(opListener);

        

 

        

    

    JPanel isi = new JPanel();

     isi.setLayout(new BorderLayout());

     isi.add(displayField, BorderLayout.NORTH );

        isi.add(buttonPanel, BorderLayout.CENTER);

        isi.add(opPanel, BorderLayout.EAST);

     

     this.setContentPane(isi);

  this.pack();

  

  }

      private void actionHapusSemua() {

        angkaPertama = true;     

        displayField.setText("0");

        operator  = "=";

        logik.totalSekarang("0");

  }

  

  private void actionHapus() {

        angkaPertama = false;  

        displayField.setText("0");

        operator  = "=";

        

  }

    

  

    class OpListener implements ActionListener {

        public void actionPerformed(ActionEvent e) {

                 angkaPertama = true;  

     String displayText = displayField.getText();

                    

                    if (operator.equals("=")) {

                        logik.totalSekarang(displayText);

                    } else if (operator.equals("+")) {

                        logik.tambah(displayText);

                    } else if (operator.equals("-")) {

                        logik.kurang(displayText);

                    } else if (operator.equals("*")) {

                        logik.kali(displayText);

                    } else if (operator.equals("/")) {

                        logik.bagi(displayText);

                    }

                    

                    displayField.setText("" + logik.keluarkanInput());

                operator = e.getActionCommand();

            

        }

    }

    

    

    class NumListener implements ActionListener {

        public void actionPerformed(ActionEvent e) {

            String numerik = e.getActionCommand(); 

            if (angkaPertama) {

                displayField.setText(numerik);

                angkaPertama = false;

            } else {

      

                displayField.setText(displayField.getText() + numerik);

            }

        }

    }

    

    



    class ClearListener implements ActionListener {

        public void actionPerformed(ActionEvent e) {

            actionHapusSemua();

        }

    }

 

 class HapusListener implements ActionListener {

        public void actionPerformed(ActionEvent e) {

            actionHapusSemua();

        }

    }

  

   

}

  

public class OtakKalkulator {

    

    private int totalSekarang;  

    public OtakKalkulator() {

        totalSekarang = 0;

    }

    

    public String keluarkanInput() {

        return "" + totalSekarang;

    }

    

    public void totalSekarang(String n) {

       totalSekarang = StringKeInterger(n);

    }

    

    public void tambah(String n) {

       totalSekarang+= StringKeInterger(n);

    }

    

    public void kurang(String n) {

        totalSekarang-= StringKeInterger(n);

    }

    

    public void kali(String n) {

        totalSekarang *= StringKeInterger(n);

    }

    

    public void bagi(String n) {

        totalSekarang /= StringKeInterger(n);

    }

    

    private int StringKeInterger(String n) {

        return Integer.parseInt(n);

    }

}