import javax.swing.*;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import java.awt.*;

public class Epitrohoid {
    private JPanel MainPanel;
    private JSpinner radiusSpinner;
    private JLabel Radius;
    private JLabel S;
    private JTextArea SText;
    private CanvasPanel canvasPanel;

    public Epitrohoid() {
        radiusSpinner.addChangeListener(new ChangeListener() {
            @Override
            public void stateChanged(ChangeEvent e) {
                int radius = (int) radiusSpinner.getValue();
                double area = Math.PI * radius * radius;
                canvasPanel.setRadius(radius);
                SText.setText(String.format("%.2f", area));
            }
        });
        radiusSpinner.setValue(50);
    }
    public static void main(String[] args) {
        JFrame frame = new JFrame("Epitrohoid");
        Epitrohoid app = new Epitrohoid();
        app.createUIComponents();
        frame.setPreferredSize(new Dimension(300, 500));
        frame.setResizable(false);
        frame.setContentPane(app.MainPanel);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setVisible(true);
    }

    private void createUIComponents() {
        canvasPanel = new CanvasPanel();
    }
}