Java Drawing Multiple Shapes (1 of 2)

/*
 * The FigurePanel class in Listing 13.3 can display lines, rectangles, round-cornered rectangles and ovals. Add appropriate new code in the class to display arcs
 * and polygons. Write a test program to display the shapes as shown in Figure 13.28a using the new FigurePanel class.
 */
import java.awt.*;

import javax.swing.*;

@SuppressWarnings("serial")
public class ImproveFigurePanel extends JFrame
{
    public ImproveFigurePanel()
    {
        setLayout(new GridLayout(2, 5, 5, 5));
        add(new FigurePanel(FigurePanel.LINE));
        add(new FigurePanel(FigurePanel.RECTANGLE));
        add(new FigurePanel(FigurePanel.ROUND_RECTANGLE));
        add(new FigurePanel(FigurePanel.OVAL));
        add(new FigurePanel(FigurePanel.RECTANGLE, true));
        add(new FigurePanel(FigurePanel.ROUND_RECTANGLE, true));
        add(new ArcsPanel());
        add(new ArcsPanel(true));
        add(new PolygonPanel());
        add(new PolygonPanel(true));
    }

    public static void main(String[] args)
    {
        ImproveFigurePanel frame = new ImproveFigurePanel();
        frame.setSize(400, 200);
        frame.setTitle("TestFigurePanel");
        frame.setLocationRelativeTo(null);
        frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
        frame.setVisible(true);
    }
}

@SuppressWarnings("serial")
// ArcsPanel class
class ArcsPanel extends JPanel
{
    private boolean filled;

    public ArcsPanel()
    {
    }

    public ArcsPanel(boolean filled)
    {
        this.filled = filled;
    }

    @Override // Draw four blades of a fan
    protected void paintComponent(Graphics g)
    {
        super.paintComponent(g);

        int xCenter = getWidth() / 2;
        int yCenter = getHeight() / 2;
        int radius = (int)(Math.min(getWidth(), getHeight()) * 0.4);

        int x = xCenter - radius;
        int y = yCenter - radius;
        g.setColor(Color.green);

        if(filled)
        {
            g.fillArc(x, y, 2 * radius, 2 * radius, 0, 30);
            g.fillArc(x, y, 2 * radius, 2 * radius, 90, 30);
            g.fillArc(x, y, 2 * radius, 2 * radius, 180, 30);
            g.fillArc(x, y, 2 * radius, 2 * radius, 270, 30);
        }
        else
        {
            g.drawArc(x, y, 2 * radius, 2 * radius, 0, 30);
            g.drawArc(x, y, 2 * radius, 2 * radius, 90, 30);
            g.drawArc(x, y, 2 * radius, 2 * radius, 180, 30);
            g.drawArc(x, y, 2 * radius, 2 * radius, 270, 30);
        }
    }
}

@SuppressWarnings("serial")
// PolygonPanel class
class PolygonPanel extends JPanel
{
    private boolean filled;

    public PolygonPanel()
    {
    }

    public PolygonPanel(boolean filled)
    {
        this.filled = filled;
    }

    protected void paintComponent(Graphics g)
    {
        super.paintComponent(g);

        int xCenter = getWidth() / 2;
        int yCenter = getHeight() / 2;
        int radius = (int)(Math.min(getWidth(), getHeight()) * 0.4);
        g.setColor(Color.yellow);

        // Create new polygon object
        Polygon polygon = new Polygon();

        // Add points to the polygon in this order
        polygon.addPoint(xCenter + radius, yCenter);
        polygon.addPoint((int)(xCenter + radius *
                Math.cos(2 * Math.PI / 6)), (int)(yCenter - radius *
                Math.sin(2 * Math.PI / 6)));
        polygon.addPoint((int)(xCenter + radius *
                Math.cos(2 * 2 * Math.PI / 6)), (int)(yCenter - radius *
                Math.sin(2 * 2 * Math.PI / 6)));
        polygon.addPoint((int)(xCenter + radius *
                Math.cos(3 * 2 * Math.PI / 6)), (int)(yCenter - radius *
                Math.sin(3 * 2 * Math.PI / 6)));
        polygon.addPoint((int)(xCenter + radius *
                Math.cos(4 * 2 * Math.PI / 6)), (int)(yCenter - radius *
                Math.sin(4 * 2 * Math.PI / 6)));
        polygon.addPoint((int)(xCenter + radius *
                Math.cos(5 * 2 * Math.PI / 6)), (int)(yCenter - radius *
                Math.sin(5 * 2 * Math.PI / 6)));

        // Draw the polygon
        if(filled)
            g.fillPolygon(polygon);
        else
            g.drawPolygon(polygon);
    }
}