[gimp/gimp-2-10] app: fix dynamics editor "fade" curve color

[Ell <ell src gnome org>]

commit ed8f80bf4b33cb6dd1d9f47af9dbf6b243e9b280
Author: Ell <ell_se yahoo com>
Date:   Tue Jul 17 09:13:55 2018 -0400

    app: fix dynamics editor "fade" curve color
    
    In the dynamics editor, use the neutral curve color, which depends
    on the current theme, for the "fade" curve, instead of hard-coding
    it to dark gray, which is hardly visible with dark themes.
    
    (cherry picked from commit b2a9bb4688b07826a4d4f6d74793890156ddf79c)

 app/widgets/gimpdynamicsoutputeditor.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)
---
diff --git a/app/widgets/gimpdynamicsoutputeditor.c b/app/widgets/gimpdynamicsoutputeditor.c
index 2a54ee355a..2fbad0e1de 100644
--- a/app/widgets/gimpdynamicsoutputeditor.c
+++ b/app/widgets/gimpdynamicsoutputeditor.c
@@ -73,9 +73,11 @@ inputs[] =
   { "use-tilt",      "tilt-curve",      N_("Tilt"),             { 1.0, 0.5, 0.0, 1.0 } },
   { "use-wheel",     "wheel-curve",     N_("Wheel / Rotation"), { 1.0, 0.0, 1.0, 1.0 } },
   { "use-random",    "random-curve",    N_("Random"),           { 0.0, 1.0, 1.0, 1.0 } },
-  { "use-fade",      "fade-curve",      N_("Fade"),             { 0.2, 0.2, 0.2, 1.0 } }
+  { "use-fade",      "fade-curve",      N_("Fade"),             { 0.5, 0.5, 0.5, 0.0 } }
 };
 
+#define INPUT_COLOR(i) (inputs[(i)].color.a ? &inputs[(i)].color : NULL)
+
 
 typedef struct _GimpDynamicsOutputEditorPrivate GimpDynamicsOutputEditorPrivate;
 
@@ -420,7 +422,7 @@ gimp_dynamics_output_editor_activate_input (GimpDynamicsOutputEditor *editor,
       if (input == i)
         {
           gimp_curve_view_set_curve (GIMP_CURVE_VIEW (private->curve_view),
-                                     input_curve, &inputs[i].color);
+                                     input_curve, INPUT_COLOR (i));
           private->active_curve = input_curve;
 
           gimp_curve_view_set_x_axis_label (GIMP_CURVE_VIEW (private->curve_view),
@@ -429,8 +431,7 @@ gimp_dynamics_output_editor_activate_input (GimpDynamicsOutputEditor *editor,
       else if (use_input)
         {
           gimp_curve_view_add_background (GIMP_CURVE_VIEW (private->curve_view),
-                                          input_curve,
-                                          &inputs[i].color);
+                                          input_curve, INPUT_COLOR (i));
         }
 
       g_object_unref (input_curve);
@@ -470,8 +471,7 @@ gimp_dynamics_output_editor_notify_output (GimpDynamicsOutput       *output,
               if (use_input)
                 {
                   gimp_curve_view_add_background (GIMP_CURVE_VIEW (private->curve_view),
-                                                  input_curve,
-                                                  &inputs[i].color);
+                                                  input_curve, INPUT_COLOR (i));
                 }
               else
                 {