123 lines
3.2 KiB
Java
123 lines
3.2 KiB
Java
import java.awt.*;
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import java.awt.event.*;
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import javax.swing.*;
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public class Calculator extends JFrame implements ActionListener {
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private JTextField display;
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private double result = 0;
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private String operator = "=";
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private boolean calculating = true;
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public Calculator() {
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display = new JTextField("0", 20);
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display.setHorizontalAlignment(JTextField.RIGHT);
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display.setEditable(false);
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// Create panel with grid layout for buttons
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JPanel buttonPanel = new JPanel();
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buttonPanel.setLayout(new GridLayout(4, 4, 5, 5));
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String[] buttonLabels = {
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"7",
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"8",
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"9",
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"/",
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"4",
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"5",
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"6",
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"*",
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"1",
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"2",
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"3",
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"-",
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"0",
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".",
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"=",
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"+",
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};
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for (String label : buttonLabels) {
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JButton button = new JButton(label);
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buttonPanel.add(button);
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button.addActionListener(this);
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}
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JButton clearButton = new JButton("C");
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clearButton.addActionListener(e -> {
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result = 0;
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operator = "=";
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calculating = true;
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display.setText("0");
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});
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// Layout
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setLayout(new BorderLayout(5, 5));
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add(display, BorderLayout.NORTH);
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add(buttonPanel, BorderLayout.CENTER);
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add(clearButton, BorderLayout.SOUTH);
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setTitle("Simple Calculator");
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setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
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pack();
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setLocationRelativeTo(null);
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}
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public void actionPerformed(ActionEvent event) {
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String command = event.getActionCommand();
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if (
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(command.charAt(0) >= '0' && command.charAt(0) <= '9') ||
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command.equals(".")
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) {
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if (calculating) {
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display.setText(command);
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} else {
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display.setText(display.getText() + command);
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}
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calculating = false;
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} else {
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if (calculating) {
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if (command.equals("-")) {
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display.setText(command);
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calculating = false;
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} else {
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operator = command;
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}
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} else {
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double x = Double.parseDouble(display.getText());
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calculate(x);
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operator = command;
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calculating = true;
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}
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}
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}
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private void calculate(double n) {
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switch (operator) {
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case "+":
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result += n;
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break;
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case "-":
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result -= n;
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break;
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case "*":
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result *= n;
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break;
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case "/":
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result /= n;
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break;
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case "=":
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result = n;
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break;
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}
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display.setText("" + result);
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}
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public static void main(String[] args) {
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SwingUtilities.invokeLater(() -> {
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new Calculator().setVisible(true);
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});
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}
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}
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