```
01: import java.awt.*;
02: import java.awt.geom.*;
03:
04: /**
05:    A circular node that is filled with a color.
06: */
07: public class CircleNode implements Node
08: {
09:    /**
10:       Construct a circle node with a given size and color.
11:       @param aColor the fill color
12:    */
13:    public CircleNode(Color aColor)
14:    {
15:       size = DEFAULT_SIZE;
16:       x = 0;
17:       y = 0;
18:       color = aColor;
19:    }
20:
21:    public Object clone()
22:    {
23:       try
24:       {
25:          return super.clone();
26:       }
27:       catch (CloneNotSupportedException exception)
28:       {
29:          return null;
30:       }
31:    }
32:
33:    public void draw(Graphics2D g2)
34:    {
35:       Ellipse2D circle = new Ellipse2D.Double(
36:          x, y, size, size);
37:       Color oldColor = g2.getColor();
38:       g2.setColor(color);
39:       g2.fill(circle);
40:       g2.setColor(oldColor);
41:       g2.draw(circle);
42:    }
43:
44:    public void translate(double dx, double dy)
45:    {
46:       x += dx;
47:       y += dy;
48:    }
49:
50:    public boolean contains(Point2D p)
51:    {
52:       Ellipse2D circle = new Ellipse2D.Double(
53:          x, y, size, size);
54:       return circle.contains(p);
55:    }
56:
57:    public Rectangle2D getBounds()
58:    {
59:       return new Rectangle2D.Double(
60:          x, y, size, size);
61:    }
62:
63:    public Point2D getConnectionPoint(Point2D other)
64:    {
65:       double centerX = x + size / 2;
66:       double centerY = y + size / 2;
67:       double dx = other.getX() - centerX;
68:       double dy = other.getY() - centerY;
69:       double distance = Math.sqrt(dx * dx + dy * dy);
70:       if (distance == 0) return other;
71:       else return new Point2D.Double(
72:          centerX + dx * (size / 2) / distance,
73:          centerY + dy * (size / 2) / distance);
74:    }
75:
76:    private int x;
77:    private int y;
78:    private int size;
79:    private Color color;
80:    private static final int DEFAULT_SIZE = 20;
81: }

```