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Expand|Select|Wrap|Line Numbers
- import java.awt.*;
- import javax.swing.*;
- import java.lang.*;
- import java.awt.event.*;
- import java.util.*;
- import javax.swing.event.*;
- public class Calculator extends JFrame {
- JTextField textField;
- private boolean startNumber= true;
- private int resultTotal;
- private String operator= "=";
- public static void main(String[] args) {
- Calculator calc = new Calculator();
- calc.setVisible(true);
- }
- public Calculator() {
- setTitle("Calculator");
- setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
- setSize(300,400);
- setLayout(new BorderLayout());
- JPanel textPanel= new JPanel();
- textPanel.setLayout(new FlowLayout());
- textField= new JTextField("0", 20);
- textField.setHorizontalAlignment(JTextField.RIGHT);
- textField.setBackground(Color.WHITE);
- textPanel.add(textField);
- add(textPanel, BorderLayout.NORTH);
- JPanel arithmeticFunctions= new JPanel();
- arithmeticFunctions.setBackground(Color.WHITE);
- arithmeticFunctions.setLayout(new GridLayout(5,1));
- JButton divideButton= new JButton("/");
- divideButton.addActionListener(new operatorListener());
- arithmeticFunctions.add(divideButton);
- JButton multiplyButton= new JButton("x");
- multiplyButton.addActionListener(new operatorListener());
- arithmeticFunctions.add(multiplyButton);
- JButton subtractButton= new JButton("-");
- subtractButton.addActionListener(new operatorListener());
- arithmeticFunctions.add(subtractButton);
- JButton addButton= new JButton("+");
- addButton.addActionListener(new operatorListener());
- arithmeticFunctions.add(addButton);
- JButton equalButton= new JButton("=");
- equalButton.addActionListener(new operatorListener());
- arithmeticFunctions.add(equalButton);
- add(arithmeticFunctions, BorderLayout.EAST);
- JPanel numberPad= new JPanel();
- numberPad.setBackground(Color.WHITE);
- numberPad.setLayout(new GridLayout(4,3));
- JButton seven= new JButton("7");
- seven.addActionListener(new numberListener());
- numberPad.add(seven);
- JButton eight= new JButton("8");
- eight.addActionListener(new numberListener());
- numberPad.add(eight);
- JButton nine= new JButton("9");
- nine.addActionListener(new numberListener());
- numberPad.add(nine);
- JButton four= new JButton("4");
- four.addActionListener(new numberListener());
- numberPad.add(four);
- JButton five= new JButton("5");
- five.addActionListener(new numberListener());
- numberPad.add(five);
- JButton six= new JButton("6");
- six.addActionListener(new numberListener());
- numberPad.add(six);
- JButton one= new JButton("1");
- one.addActionListener(new numberListener());
- numberPad.add(one);
- JButton two= new JButton("2");
- two.addActionListener(new numberListener());
- numberPad.add(two);
- JButton three= new JButton("3");
- three.addActionListener(new numberListener());
- numberPad.add(three);
- JButton zero= new JButton("0");
- zero.addActionListener(new numberListener());
- numberPad.add(zero);
- JButton decimal= new JButton(".");
- decimal.addActionListener(new numberListener());
- numberPad.add(decimal);
- JButton posNeg= new JButton("+/=");
- numberPad.add(posNeg);
- add(numberPad, BorderLayout.WEST);
- JPanel cent= new JPanel();
- cent.setBackground(Color.WHITE);
- cent.setLayout(new FlowLayout());
- JButton c= new JButton("C");
- cent.add(c);
- add(cent, BorderLayout.CENTER);
- }
- private void actionClear() {
- startNumber= true;
- textField.setText("0");
- resultTotal=0;
- operator= "=";
- }
- public class numberListener implements ActionListener {
- public void actionPerformed(ActionEvent e) {
- String number= e.getActionCommand();
- if (startNumber) {
- textField.setText(number);
- startNumber= false;
- }
- else {
- textField.setText(textField.getText()+ number);
- }
- }
- }
- public class operatorListener implements ActionListener {
- public void actionPerformed(ActionEvent e) {
- if (startNumber)
- actionClear();
- else
- startNumber= true;
- try {
- String numOperator= textField.getText();
- int currentTotal= Integer.parseInt(numOperator);
- if (operator.equals("/")) {
- resultTotal /= currentTotal;
- }
- else if (operator.equals("x")) {
- resultTotal *= currentTotal;
- }
- else if (operator.equals("-")) {
- resultTotal -= currentTotal;
- }
- else if (operator.equals("+")) {
- resultTotal += currentTotal;
- }
- if (operator.equals("=")) {
- resultTotal= currentTotal;
- }
- textField.setText("" + resultTotal);
- }
- catch (NumberFormatException ex) {
- actionClear();
- }
- operator= e.getActionCommand();
- }
- }
- }
