UI/Nodes: Adding node groups via drag & drop (e.g. from Asset Browser)

Adds `NODE_OT_add_group` operator to add a node group from a given name, and
uses that to register a node editor drop-box.
When dropping a node-group asset, the ID will be appended. This is what we do
for other ID assets too.

Should the node group insertion fail (e.g. the group is not compatible with the
current tree, as checked by the poll), the appended data-block is removed.

Differential Revision: https://developer.blender.org/D10405

Reviewed by: Jacques Lucke

1 files changed, 2 insertions, 0 deletions

diff --git a/source/blender/editors/space_node/node_intern.h b/source/blender/editors/space_node/node_intern.h
index 2f3fa6996af..ee1193af8d0 100644
--- a/source/blender/editors/space_node/node_intern.h
+++ b/source/blender/editors/space_node/node_intern.h
@@ -194,11 +194,13 @@ void draw_nodespace_back_pix(const struct bContext *C,
 bNode *node_add_node(
     const struct bContext *C, const char *idname, int type, float locx, float locy);
 void NODE_OT_add_reroute(struct wmOperatorType *ot);
+void NODE_OT_add_group(struct wmOperatorType *ot);
 void NODE_OT_add_file(struct wmOperatorType *ot);
 void NODE_OT_add_mask(struct wmOperatorType *ot);
 void NODE_OT_new_node_tree(struct wmOperatorType *ot);
 
 /* node_group.c */
+const char *node_group_idname(struct bContext *C);
 void NODE_OT_group_make(struct wmOperatorType *ot);
 void NODE_OT_group_insert(struct wmOperatorType *ot);
 void NODE_OT_group_ungroup(struct wmOperatorType *ot);