This widget is considered too specialized or little-used for
PyGTK, and will in the future be moved to some other package. If your
application needs this widget, feel free to use it, as the widget does work
and is useful in some applications; it's just not of general interest.
However, it will eventually move out of the PyGTK distribution.
The gtk.GammaCurve
widget is a variant of gtk.Curve
specifically for editing gamma curves, which are used in graphics
applications such as the Gimp. The gtk.GammaCurve
widget shows a curve which the user can edit with the mouse just like a
gtk.Curve
widget. On the right of the curve it also displays 5 buttons, 3 of which
change between the 3 curve modes (spline, linear and free), and the other 2
set the curve to a particular gamma value, or reset it to a straight
line.