import java.awt.*;
import java.awt.geom.*;
import javax.swing.*;
import java.util.*;
import java.awt.event.*;


public class DrawCircle
{
    public static int size = 500;
    public static Color color = Color.RED;

    public static void main(String[] args)
    {
        DrawFrame frame = new DrawFrame(size, color);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }
}

class DrawFrame extends JFrame
{
    public DrawFrame(int size, Color color)
    {
        setTitle("Drawing Circle");
        setSize(size, size + 31);

        DrawPanel panel = new DrawPanel(size, color);
        add(panel);
    }
}

class DrawPanel extends JPanel
{
    Color color;

    double centerX;
    double centerY;
    double radius;

    int brush_counter = 0;

    private ArrayList<Ellipse2D> circles;

    public DrawPanel(int size, Color color)
    {
        this.color = color;
        centerX = centerY = radius = size / 2;
        circles = new ArrayList<Ellipse2D>();

        JButton brushAreaRed = new JButton("Red");
        add(brushAreaRed);

        JButton brushAreaBlue = new JButton("Blue");
        add(brushAreaBlue);

        JButton brushAreaGreen = new JButton("Green");
        add(brushAreaGreen);

        ColorAction brushAreaActionRed = new ColorAction(Color.RED);
        ColorAction brushAreaActionBlue = new ColorAction(Color.BLUE);
        ColorAction brushAreaActionGreen = new ColorAction(Color.GREEN);

        brushAreaRed.addActionListener(brushAreaActionRed);
        brushAreaBlue.addActionListener(brushAreaActionBlue);
        brushAreaGreen.addActionListener(brushAreaActionGreen);
    }

    public void brushAndRepaint(Color color)
    {
        this.color = color;

        if (brush_counter == 0)
        {
            Ellipse2D circle = new Ellipse2D.Double();
            circle.setFrameFromCenter(centerX, centerY, centerX + radius, centerY + radius);
            circles.add(circle);
            brush_counter++;

        } else if (brush_counter == 1)
        {
            for (double i = radius; i > 0; i = i - 0.1)
            {
                Ellipse2D circle = new Ellipse2D.Double();
                circle.setFrameFromCenter(centerX, centerY, centerX + i, centerY + i);
                circles.add(circle);
            }
            brush_counter++;
        } else
        {
            Ellipse2D initial = circles.get(0);
            circles = new ArrayList<Ellipse2D>();
            circles.add(initial);
            brush_counter = 0;
        }
        repaint();
    }

    public void paintComponent(Graphics g)
    {
        super.paintComponent(g);
        Graphics2D g2 = (Graphics2D) g;

        Stroke stroke = new BasicStroke(1f);
        g2.setStroke(stroke);

        for (Ellipse2D circle : circles)
        {
            g2.setColor(this.color);
            g2.draw(circle);
        }

    }

    private class ColorAction implements ActionListener
    {
        private Color color;

        public ColorAction(Color color)
        {
            this.color = color;
        }

        public void actionPerformed(ActionEvent event)
        {
            brushAndRepaint(this.color);
        }
    }

}