adjustVisibility(this);
  public void setDot(int dot)  {    if (dot >= 0)      {        Document doc = textComponent.getDocument();        if (doc != null)          this.dot = Math.min(dot, doc.getLength());        this.dot = Math.max(this.dot, 0);        this.mark = this.dot;                clearHighlight();    adjustVisibility(this);        appear();      }  }