/// draw inset and update (xo, yo)-cache
virtual void draw(PainterInfo & pi, int x, int y) const;
/// Provide the text for the button
/// draw inset and update (xo, yo)-cache
virtual void draw(PainterInfo & pi, int x, int y) const;
/// Provide the text for the button
/// The "sensitive area" box, i.e., the button area
Box box() const { return button_box_; }
/// The "sensitive area" box, i.e., the button area
Box box() const { return button_box_; }