Arrow should be used to draw simple arrows that need to point in one of
the four cardinal directions (up, down, left, or right). The style of the
arrow can be one of shadow in, shadow out, etched in, or etched out. Note
that these directions and style types may be ammended in versions of Gtk to
Arrow will fill any space alloted to it, but since it is inherited from
Misc, it can be padded and/or aligned, to fill exactly the space the
Arrows are created with a call to arrowNew. The direction or style of
an arrow can be changed after creation by using arrowSet.