Obtains the coordinates where the label will draw the
PangoLayout representing the text in the label;
useful to convert mouse events into coordinates inside the
PangoLayout, e.g. to take some action if some part
of the label is clicked.
Of course you will need to create a GtkEventBox to
receive the events, and pack the label inside it, since labels are a
Gtk::NO_WINDOW widget. Remember when
using the PangoLayout functions you need to convert
to and from pixels using
Pango::PIXELS or PANGO_SCALE.