GtkCurve question

["Bryan W. Headley" <bwheadley earthlink net>]

Maybe an easy question...

Out of the box behavior for a GtkCurve allows the user to interact with 
the drawing area, moving/reinterpolating different points on the curve.

Question: assuming the user does indeed modify the curve, how is the 
application notified of the event? The only callback that I'm aware of 
is for changing the curve_type.

Bryan