PDPoint.java(a small class derived from the AWT class Point)
// PDPoint.java-a special markable point for the PolyDraw program.
public class PDPoint extends Point {
private static final int r = 5;
PDPoint(int anX, int aY) {
public void mark() { selected = true; }
public void unmark() { selected = false; }
public void paint(Graphics g) {
if (selected) { g.fillOval(x - r, y - r, r+r, r+r); }