[gimp] Add naive and wrong version of GimpItem::convert()

[Michael Natterer <mitch src gnome org>]

commit 62c5b23aaf9e58c1d1ce3c74a8c0b62f068625ee
Author: Michael Natterer <mitch gimp org>
Date:   Tue Aug 25 14:23:42 2009 +0200

    Add naive and wrong version of GimpItem::convert()
    
    That code will fail badly when dropping layer groups between images of
    different types, but will at least work between two RGB images.

 app/core/gimpgrouplayer.c |   22 ++++++++++++++++++++++
 1 files changed, 22 insertions(+), 0 deletions(-)
---
diff --git a/app/core/gimpgrouplayer.c b/app/core/gimpgrouplayer.c
index f2a111f..b8c68a9 100644
--- a/app/core/gimpgrouplayer.c
+++ b/app/core/gimpgrouplayer.c
@@ -66,6 +66,8 @@ static GimpContainer * gimp_group_layer_get_children (GimpViewable    *viewable)
 
 static GimpItem      * gimp_group_layer_duplicate    (GimpItem        *item,
                                                       GType            new_type);
+static void            gimp_group_layer_convert      (GimpItem        *item,
+                                                      GimpImage       *dest_image);
 static void            gimp_group_layer_translate    (GimpItem        *item,
                                                       gint             offset_x,
                                                       gint             offset_y,
@@ -160,6 +162,7 @@ gimp_group_layer_class_init (GimpGroupLayerClass *klass)
   viewable_class->get_children     = gimp_group_layer_get_children;
 
   item_class->duplicate            = gimp_group_layer_duplicate;
+  item_class->convert              = gimp_group_layer_convert;
   item_class->translate            = gimp_group_layer_translate;
   item_class->scale                = gimp_group_layer_scale;
   item_class->resize               = gimp_group_layer_resize;
@@ -360,6 +363,25 @@ gimp_group_layer_duplicate (GimpItem *item,
 }
 
 static void
+gimp_group_layer_convert (GimpItem  *item,
+                          GimpImage *dest_image)
+{
+  GimpGroupLayer *group = GIMP_GROUP_LAYER (item);
+  GList          *list;
+
+  for (list = GIMP_LIST (group->children)->list;
+       list;
+       list = g_list_next (list))
+    {
+      GimpItem *child = list->data;
+
+      GIMP_ITEM_GET_CLASS (child)->convert (child, dest_image);
+    }
+
+  GIMP_ITEM_CLASS (parent_class)->convert (item, dest_image);
+}
+
+static void
 gimp_group_layer_translate (GimpItem *item,
                             gint      offset_x,
                             gint      offset_y,