[gimp] app: remove gimp_image_get_active_drawable() usage in colormap actions.

[Jehan <jehanp src gnome org>]

commit 831cb913039d289afc5dc875c420f2348e32c3db
Author: Jehan <jehan girinstud io>
Date:   Thu Oct 20 00:39:10 2022 +0200

    app: remove gimp_image_get_active_drawable() usage in colormap actions.

 app/actions/colormap-actions.c  | 10 +++++++---
 app/actions/colormap-commands.c | 15 ++++++++++++++-
 2 files changed, 21 insertions(+), 4 deletions(-)
---
diff --git a/app/actions/colormap-actions.c b/app/actions/colormap-actions.c
index 292bfb2bca..abfab26d23 100644
--- a/app/actions/colormap-actions.c
+++ b/app/actions/colormap-actions.c
@@ -130,10 +130,14 @@ colormap_actions_update (GimpActionGroup *group,
 
       if (indexed)
         {
-          GimpDrawable *drawable = gimp_image_get_active_drawable (image);
+          GList *drawables = gimp_image_get_selected_drawables (image);
 
-          num_colors       = gimp_image_get_colormap_size (image);
-          drawable_indexed = gimp_drawable_is_indexed (drawable);
+          num_colors = gimp_image_get_colormap_size (image);
+
+          if (g_list_length (drawables) == 1)
+            drawable_indexed = gimp_drawable_is_indexed (drawables->data);
+
+          g_list_free (drawables);
         }
     }
 
diff --git a/app/actions/colormap-commands.c b/app/actions/colormap-commands.c
index 09a782168f..43bbc0da8a 100644
--- a/app/actions/colormap-commands.c
+++ b/app/actions/colormap-commands.c
@@ -81,6 +81,7 @@ colormap_to_selection_cmd_callback (GimpAction *action,
   GimpColormapSelection *selection;
   GimpColormapEditor    *editor;
   GimpImage             *image;
+  GList                 *drawables;
   GimpChannelOps         op;
   gint                   col_index;
 
@@ -92,10 +93,22 @@ colormap_to_selection_cmd_callback (GimpAction *action,
 
   op = (GimpChannelOps) g_variant_get_int32 (value);
 
+  drawables = gimp_image_get_selected_drawables (image);
+  if (g_list_length (drawables) != 1)
+    {
+      /* We should not reach this anyway as colormap-actions.c normally takes
+       * care at making the action insensitive when the item selection is wrong.
+       */
+      g_warning ("This action requires exactly one selected drawable.");
+      g_list_free (drawables);
+      return;
+    }
+
   gimp_channel_select_by_index (gimp_image_get_mask (image),
-                                gimp_image_get_active_drawable (image),
+                                drawables->data,
                                 col_index, op,
                                 FALSE, 0.0, 0.0);
 
+  g_list_free (drawables);
   gimp_image_flush (image);
 }