2006-08-31  Michael Natterer  <mitch@gimp.org>

	* app/core/gimpgradient.[ch] (gimp_gradient_has_fg_bg_segments):
	new funtion which returns TRUE if any of the gradient's segments
	refer to FG of BG.

	(gimp_gradient_segment_get_left_color_type)
	(gimp_gradient_segment_set_left_color_type)
	(gimp_gradient_segment_get_right_color_type)
	(gimp_gradient_segment_set_right_color_type): new accessors for
	the new GimpGradientColor stuff.

	(gimp_gradient_segment_split_midpoint)
	(gimp_gradient_segment_range_flip)
	(gimp_gradient_segment_range_replicate): split, flip and replicate
	the segments' color_types too.

	* app/widgets/gimpviewrenderer.[ch]: added virtual functions
	::set_context() and ::invalidate() and call them.

	* app/widgets/gimpviewrenderergradient.[ch]: implement the virtual
	functions. Connect to the context's "foreground-changed" and
	"background-changed" signals if the gradient contains FG or BG
	colors and invalidate the renderer whenever they change.

	* app/core/gimp-gradients.c: removed signal connections which
	invalidated the gradients on FG/BG changes of the user context.