void DragLabel::mouseUp(const MouseEvent& e)
{
    // By showing the editor here (instead of letting the base class do it
    // for us) we can get a pointer to the editor and make sure that users
    // can't enter anything except 1..5 digits.
    this->showEditor();
    TextEditor* ed = this->getCurrentTextEditor();
    if (ed)
    {
        ed->setInputRestrictions(5, "0123456789");
    }
    Label::mouseUp(e);
}