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 void setColor(Color aColor)
22:    {
23:       color = aColor;
24:    }
25: 
26:    public Color getColor()
27:    {
28:       return color;
29:    }
30: 
31:    public Object clone()
32:    {
33:       try
34:       {
35:          return super.clone();
36:       }
37:       catch (CloneNotSupportedException exception)
38:       {
39:          return null;
40:       }
41:    }
42: 
43:    public void draw(Graphics2D g2)
44:    {
45:       Ellipse2D circle = new Ellipse2D.Double(
46:          x, y, size, size);
47:       Color oldColor = g2.getColor();
48:       g2.setColor(color);
49:       g2.fill(circle);
50:       g2.setColor(oldColor);
51:       g2.draw(circle);
52:    }
53: 
54:    public void translate(double dx, double dy)
55:    {
56:       x += dx;
57:       y += dy;
58:    }
59: 
60:    public boolean contains(Point2D p)
61:    {
62:       Ellipse2D circle = new Ellipse2D.Double(
63:          x, y, size, size);
64:       return circle.contains(p);
65:    }
66: 
67:    public Rectangle2D getBounds()
68:    {
69:       return new Rectangle2D.Double(
70:          x, y, size, size);
71:    }
72: 
73:    public Point2D getConnectionPoint(Point2D other)
74:    {
75:       double centerX = x + size / 2;
76:       double centerY = y + size / 2;
77:       double dx = other.getX() - centerX;
78:       double dy = other.getY() - centerY;
79:       double distance = Math.sqrt(dx * dx + dy * dy);
80:       if (distance == 0) return other;
81:       else return new Point2D.Double(
82:          centerX + dx * (size / 2) / distance,
83:          centerY + dy * (size / 2) / distance);
84:    }
85: 
86:    private int x;
87:    private int y;
88:    private int size;
89:    private Color color;  
90:    private static final int DEFAULT_SIZE = 20;
91: }