Text is drawn via Pango Layouts. The easiest way to create a
Pango::Layout is to use
create_pango_layout. Once created, the layout
can be manipulated in various ways, including changing the text,
font, etc. Finally, the layout can be rendered using the
draw_layout method of
Gdk::Drawable, which takes a
Gdk::GC object, an x-position, a
y-position and the layout itself.
TODO: Update this section for Cairo instead of Gdk::GC.