private static Point fixPopupLocation(final Component contents, final int x, final int y) {
      if (!(contents instanceof JToolTip)) return new Point(x, y);

      final PointerInfo info;
      try {
        info = MouseInfo.getPointerInfo();
      } catch (InternalError e) {
        // http://www.jetbrains.net/jira/browse/IDEADEV-21390
        // may happen under Mac OSX 10.5
        return new Point(x, y);
      }
      int deltaY = 0;

      if (info != null) {
        final Point mouse = info.getLocation();
        deltaY = mouse.y - y;
      }

      final Dimension size = contents.getPreferredSize();
      final Rectangle rec = new Rectangle(new Point(x, y), size);
      ScreenUtil.moveRectangleToFitTheScreen(rec);

      if (rec.y < y) {
        rec.y += deltaY;
      }

      return rec.getLocation();
    }
 /**
  * Act - do whatever the Desicion wants to do. This method is called whenever the 'Act' or 'Run'
  * button gets pressed in the environment.
  */
 public void act() {
   MouseInfo mouse = Greenfoot.getMouseInfo();
   if (Greenfoot.mouseClicked(this)) {
     if (mouse.getButton() == 3) // right-click
     {
       construyeDialogo();
     } else {
       if (((WActividades) getWorld()).mousePresionado) {
         ((WActividades) getWorld()).agregaPunto(getX(), getY(), true);
         ((WActividades) getWorld()).mousePresionado = false;
       }
     }
   } else if (Greenfoot.mousePressed(this)) {
     ((WActividades) getWorld()).agregaPunto(getX(), getY(), false);
     ((WActividades) getWorld()).mousePresionado = true;
   }
 }
  @Override
  protected void paintChildren(Graphics g) {

    autoscale();

    super.paintChildren(g);
    if (IGV.getInstance().isRulerEnabled()) {
      int start = MouseInfo.getPointerInfo().getLocation().x - getLocationOnScreen().x;
      g.setColor(Color.BLACK);
      g.drawLine(start, 0, start, getHeight());
    }
  }