private void createFeedback() {
    if (myFeedback == null) {
      FeedbackLayer layer = myContext.getArea().getFeedbackLayer();

      myFeedback = new RectangleFeedback(Color.blue, 2);
      layer.add(myFeedback);

      myTextFeedback = new TextFeedback();
      myTextFeedback.setBorder(new LineMarginBorder(0, 5, 3, 0));
      layer.add(myTextFeedback);
      layer.add(myWrapFeedback);
      layer.add(myFillFeedback);

      layer.repaint();
    }
  }
  @Override
  public void eraseFeedback() {
    if (myFeedback != null) {
      FeedbackLayer layer = myContext.getArea().getFeedbackLayer();
      layer.remove(myFeedback);
      layer.remove(myTextFeedback);
      layer.remove(myWrapFeedback);
      layer.remove(myFillFeedback);

      layer.repaint();

      myFeedback = null;
      myTextFeedback = null;
      myWrapFeedback = null;
      myFillFeedback = null;
    }
  }