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.