package shapes;

import java.util.ArrayList;

public class ShapeList extends ArrayList<Shape>
{
    
    private int currentIndex = 0;
    
    public Shape next()
    {
        if (size() == 0) return null;
        if (currentIndex++ >= size() - 1) {
            currentIndex = 0;
        }
        return get(currentIndex);
    }
}