app, libgimp*: more GeglColor's space invasion.

- New function gimp_cairo_set_source_color() which is meant to replace
  gimp_cairo_set_source_rgb(a?)() eventually. This new function sets the Cairo
  source color, using the target monitor's profile of the widget where the Cairo
  surface is meant to be drawn on. It also uses the color management settings
  (such as whether a custom profile was set, instead of using system profile, or
  also simply whether color management was disabled at all). It doesn't
  soft-proof the color yet.
- Padding and out-of-gamut colors drawing now use the new
  gimp_cairo_set_source_color(). These don't need any soft-proofing anyway.
- Out-of-gamut color property in GimpColorConfig is now a GeglColor property.

libgimpconfig/gimpcolorconfig.c

@@ -160,7 +160,7 @@ struct _GimpColorConfigPrivate
   gboolean                  simulation_use_black_point_compensation;
   gboolean                  simulation_optimize;
   gboolean                  simulation_gamut_check;
-  GimpRGB                   out_of_gamut_color;
+  GeglColor                *out_of_gamut_color;
 
   gboolean                  show_rgb_u8;
   gboolean                  show_hsv;
@@ -209,9 +209,13 @@ static void
 gimp_color_config_class_init (GimpColorConfigClass *klass)
 {
   GObjectClass *object_class = G_OBJECT_CLASS (klass);
-  GimpRGB       color;
+  GeglColor    *magenta;
 
-  gimp_rgba_set (&color, 1.0, 0.0, 1.0, 1.0); /* magenta */
+  babl_init ();
+
+  /* Magenta (sRGB space). */
+  magenta = gegl_color_new (NULL);
+  gegl_color_set_rgba (magenta, 1.0, 0.0, 1.0, 1.0);
 
   object_class->finalize     = gimp_color_config_finalize;
   object_class->set_property = gimp_color_config_set_property;
@@ -318,12 +322,12 @@ gimp_color_config_class_init (GimpColorConfigClass *klass)
                             FALSE,
                             GIMP_PARAM_STATIC_STRINGS);
 
-  GIMP_CONFIG_PROP_RGB (object_class, PROP_OUT_OF_GAMUT_COLOR,
-                        "out-of-gamut-color",
-                        _("Out of gamut warning color"),
-                        OUT_OF_GAMUT_COLOR_BLURB,
-                        FALSE, &color,
-                        GIMP_PARAM_STATIC_STRINGS);
+  GIMP_CONFIG_PROP_COLOR (object_class, PROP_OUT_OF_GAMUT_COLOR,
+                          "out-of-gamut-color",
+                          _("Out of gamut warning color"),
+                          OUT_OF_GAMUT_COLOR_BLURB,
+                          magenta,
+                          GIMP_PARAM_STATIC_STRINGS);
 
   GIMP_CONFIG_PROP_BOOLEAN (object_class, PROP_SHOW_RGB_U8,
                             "show-rgb-u8",
@@ -338,12 +342,20 @@ gimp_color_config_class_init (GimpColorConfigClass *klass)
                             _("Show HSV instead of LCH"),
                             FALSE,
                             GIMP_PARAM_STATIC_STRINGS);
+
+  g_object_unref (magenta);
 }
 
 static void
 gimp_color_config_init (GimpColorConfig *config)
 {
+  GeglColor *magenta = gegl_color_new (NULL);
+
   config->priv = gimp_color_config_get_instance_private (config);
+
+  /* Magenta (sRGB space). */
+  gegl_color_set_rgba (magenta, 1.0, 0.0, 1.0, 1.0);
+  config->priv->out_of_gamut_color = magenta;
 }
 
 static void
@@ -425,7 +437,8 @@ gimp_color_config_set_property (GObject      *object,
       priv->simulation_gamut_check = g_value_get_boolean (value);
       break;
     case PROP_OUT_OF_GAMUT_COLOR:
-      priv->out_of_gamut_color = *(GimpRGB *) g_value_get_boxed (value);
+      g_clear_object (&priv->out_of_gamut_color);
+      priv->out_of_gamut_color = gegl_color_duplicate (g_value_get_object (value));
       break;
     case PROP_SHOW_RGB_U8:
       priv->show_rgb_u8 = g_value_get_boolean (value);
@@ -499,7 +512,7 @@ gimp_color_config_get_property (GObject    *object,
       g_value_set_boolean (value, priv->simulation_gamut_check);
       break;
     case PROP_OUT_OF_GAMUT_COLOR:
-      g_value_set_boxed (value, &priv->out_of_gamut_color);
+      g_value_set_object (value, priv->out_of_gamut_color);
       break;
     case PROP_SHOW_RGB_U8:
       g_value_set_boolean (value, priv->show_rgb_u8);
@@ -649,18 +662,17 @@ gimp_color_config_get_simulation_gamut_check (GimpColorConfig *config)
 /**
  * gimp_color_config_get_out_of_gamut_color:
  * @config: a #GimpColorConfig
- * @color:  return location for a #GimpRGB
  *
+ * Returns: (transfer full): the [class@Gegl.Color] to use to represent
+ *                           out-of-gamut pixels.
  * Since: 3.0
  **/
-void
-gimp_color_config_get_out_of_gamut_color (GimpColorConfig *config,
-                                          GimpRGB         *color)
+GeglColor *
+gimp_color_config_get_out_of_gamut_color (GimpColorConfig *config)
 {
-  g_return_if_fail (GIMP_IS_COLOR_CONFIG (config));
-  g_return_if_fail (color != NULL);
+  g_return_val_if_fail (GIMP_IS_COLOR_CONFIG (config), NULL);
 
-  *color = GET_PRIVATE (config)->out_of_gamut_color;
+  return gegl_color_duplicate (GET_PRIVATE (config)->out_of_gamut_color);
 }
 
 /**

libgimpconfig/gimpcolorconfig.h

@@ -75,8 +75,7 @@ GimpColorRenderingIntent
 gboolean           gimp_color_config_get_simulation_bpc           (GimpColorConfig  *config);
 gboolean           gimp_color_config_get_simulation_optimize      (GimpColorConfig  *config);
 gboolean           gimp_color_config_get_simulation_gamut_check   (GimpColorConfig  *config);
-void               gimp_color_config_get_out_of_gamut_color       (GimpColorConfig  *config,
-                                                                   GimpRGB          *color);
+GeglColor        * gimp_color_config_get_out_of_gamut_color       (GimpColorConfig  *config);
 
 GimpColorProfile * gimp_color_config_get_rgb_color_profile        (GimpColorConfig  *config,
                                                                    GError          **error);

libgimpconfig/gimpconfig.h

@@ -19,6 +19,8 @@
 #ifndef __GIMP_CONFIG_H__
 #define __GIMP_CONFIG_H__
 
+#include <gegl.h>
+
 #define __GIMP_CONFIG_H_INSIDE__
 
 #include <libgimpconfig/gimpconfigtypes.h>