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);

 }

}