[hardwired]

Looks okay but it's hard to say. You could try using a rectangle.

Code:

//  <applet code="MovingSelection" width="400" height="400"></applet>
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import java.util.*;
import java.util.List;

public class MovingSelection extends Applet implements Runnable {
    List<TokenStore> tokens = new ArrayList<TokenStore>();
    BufferedImage buffer;
    Thread thread;
    boolean running = false;

    public void init() {
        tokens.add(new TokenStore(40,   40, Color.red,    1, 3));
        tokens.add(new TokenStore(140, 100, Color.green,  2, 2));
        tokens.add(new TokenStore(300, 200, Color.blue,   3, 2));
        tokens.add(new TokenStore(100, 325, Color.cyan,   1, 2));
        tokens.add(new TokenStore(220, 250, Color.orange, 2, 3));
        TokenSelector selector = new TokenSelector(this);
        addMouseListener(selector);
    }

    public void start() {
        if(!running) {
            running = true;
            thread = new Thread(this);
            thread.start();
        }
    }

    public void stop() {
        running = false;
        if(thread != null)
            thread.interrupt();
        thread = null;
    }

    public void paint(Graphics g) {
        if(buffer == null) {
            int w = getWidth();
            int h = getHeight();
            int type = BufferedImage.TYPE_INT_RGB;
            buffer = new BufferedImage(w, h, type);
            erase(w, h);
        }
        g.drawImage(buffer, 0, 0, this);
    }

    public void update(Graphics g) {
        paint(g);
    }

    public void run() {
        while(running) {
            repaint();
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                System.out.println(e);
            }
            updateBuffer();
            repaint();
        }
    }

    private void updateBuffer() {
        int w = buffer.getWidth();
        int h = buffer.getHeight();
        erase(w, h);
        Graphics2D g2 = buffer.createGraphics();
        for(int j = 0; j < tokens.size(); j++) {
            TokenStore token = tokens.get(j);
            if(token.isVisible())
                token.advance(w, h);
            token.draw(g2);
        }
        g2.dispose();
    }

    private void erase(int w, int h) {
        Graphics2D g2 = buffer.createGraphics();
        g2.setPaint(getBackground());
        g2.fillRect(0,0,w,h);
        g2.dispose();
    }
}

class TokenSelector extends MouseAdapter {
    MovingSelection component;

    public TokenSelector(MovingSelection ms) {
        component = ms;
    }
    
    public void mousePressed(MouseEvent e) {
        Point p = e.getPoint();
        List<TokenStore> tokens = component.tokens;
        for(int j = 0; j < tokens.size(); j++) {
            TokenStore token = tokens.get(j);
            if(token.contains(p)) {
                token.select();
                break;
            }
        }
    }
}

class TokenStore {
    Rectangle r = new Rectangle(20,20);
    Color color;
    int dx;
    int dy;
    boolean isVisible = true;

    public TokenStore(int x, int y, Color color, int dx, int dy) {
        r.setLocation(x, y);
        this.color = color;
        this.dx = dx;
        this.dy = dy;
    }

    public void draw(Graphics2D g2) {
        g2.setPaint(color);
        if(isVisible)
            g2.fill(r);
        else
            g2.draw(r);
    }

    public void advance(int w, int h) {
        if(r.x + dx < 0 || r.x + r.width + dx > w)
            dx *= -1;
        if(r.y + dy < 0 || r.y + r.height + dy > h)
            dy *= -1;
        r.translate(dx, dy);
    }

    public void select() { isVisible = !isVisible; }

    public boolean isVisible() { return isVisible; }

    public boolean contains(Point p) { return r.contains(p); }
}