import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Scanner;

public class Classthingy implements ActionListener {

    private static JTextField xTextField, yTextField, rTextField;
    private static JButton drawButton;

    private static Panel mainPanel;

    private static int x = 0, y = 0, r = 0;

    public Classthingy() {
        JFrame frame = new JFrame("Class thingy");

        xTextField = new JTextField();
        yTextField = new JTextField();
        rTextField = new JTextField();
        drawButton = new JButton("Draw");

        mainPanel = new Panel();

        xTextField.setPreferredSize(new Dimension(75, 20));
        yTextField.setPreferredSize(new Dimension(75, 20));
        rTextField.setPreferredSize(new Dimension(75, 20));

        drawButton.addActionListener(this);

        JPanel panel = new JPanel();

        panel.setLayout(new GridLayout(1, 4));

        panel.add(new JLabel("X:"));
        panel.add(xTextField);
        panel.add(new JLabel("Y:"));
        panel.add(yTextField);
        panel.add(new JLabel("R:"));
        panel.add(rTextField);

        frame.add(panel, BorderLayout.NORTH);
        frame.add(mainPanel, BorderLayout.CENTER);
        frame.add(drawButton, BorderLayout.SOUTH);

        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        x = Integer.parseInt(xTextField.getText());
        y = Integer.parseInt(yTextField.getText());
        r = Integer.parseInt(rTextField.getText());

        mainPanel.repaint();
    }

    public static void main(String[] args) {
        new Classthingy();
    }

    private static class Panel extends JPanel {
        public Panel() {
            this.setPreferredSize(new Dimension(200, 200));
            repaint();
        }

        public void paintComponent(Graphics g) {
            g.setColor(Color.BLACK);
            g.fillRect(0, 0, getWidth(), getHeight());
            g.setColor(Color.RED);
            g.fillOval(x - r, y - r, r * 2, r * 2);
        }
    }
}