Outliner:

Added drag-drop support for Groups. On drop in 3d window it creates an instance.

Todo: it adds this on 3d cursor position still. The existing drop-object-duplicate operator
is a Macro - with warning. For adding on mouse-cursor position we need a better
way (new function call, just use operator option).

2 files changed, 30 insertions, 2 deletions

diff --git a/source/blender/editors/object/object_add.c b/source/blender/editors/object/object_add.c
index b21b77e4e34..473119c90f3 100644
--- a/source/blender/editors/object/object_add.c
+++ b/source/blender/editors/object/object_add.c
@@ -802,10 +802,18 @@ void OBJECT_OT_lamp_add(wmOperatorType *ot)
 
 static int group_instance_add_exec(bContext *C, wmOperator *op)
 {
-	Group *group = BLI_findlink(&CTX_data_main(C)->group, RNA_enum_get(op->ptr, "group"));
-
+	Group *group;
 	unsigned int layer;
 	float loc[3], rot[3];
+	
+	if (RNA_struct_property_is_set(op->ptr, "name")) {
+		char name[MAX_ID_NAME - 2];
+
+		RNA_string_get(op->ptr, "name", name);
+		group = (Group *)BKE_libblock_find_name(ID_GR, name);
+	}
+	else
+		group = BLI_findlink(&CTX_data_main(C)->group, RNA_enum_get(op->ptr, "group"));
 
 	if (!ED_object_add_generic_get_opts(C, op, loc, rot, NULL, &layer, NULL))
 		return OPERATOR_CANCELLED;
@@ -847,6 +855,7 @@ void OBJECT_OT_group_instance_add(wmOperatorType *ot)
 	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
 
 	/* properties */
+	RNA_def_string(ot->srna, "name", "Group", MAX_ID_NAME - 2, "Name", "Group name to add");
 	ot->prop = RNA_def_enum(ot->srna, "group", DummyRNA_NULL_items, 0, "Group", "");
 	RNA_def_enum_funcs(ot->prop, RNA_group_itemf);
 	ED_object_add_generic_props(ot, FALSE);
diff --git a/source/blender/editors/space_view3d/space_view3d.c b/source/blender/editors/space_view3d/space_view3d.c
index 61649e105ee..4ade47fbdc7 100644
--- a/source/blender/editors/space_view3d/space_view3d.c
+++ b/source/blender/editors/space_view3d/space_view3d.c
@@ -466,6 +466,16 @@ static int view3d_ob_drop_poll(bContext *UNUSED(C), wmDrag *drag, wmEvent *UNUSE
 	return 0;
 }
 
+static int view3d_group_drop_poll(bContext *UNUSED(C), wmDrag *drag, wmEvent *UNUSED(event))
+{
+	if (drag->type == WM_DRAG_ID) {
+		ID *id = (ID *)drag->poin;
+		if (GS(id->name) == ID_GR)
+			return 1;
+	}
+	return 0;
+}
+
 static int view3d_mat_drop_poll(bContext *UNUSED(C), wmDrag *drag, wmEvent *UNUSED(event))
 {
 	if (drag->type == WM_DRAG_ID) {
@@ -520,6 +530,14 @@ static void view3d_ob_drop_copy(wmDrag *drag, wmDropBox *drop)
 		RNA_string_set(drop->ptr, "name", id->name + 2);
 }
 
+static void view3d_group_drop_copy(wmDrag *drag, wmDropBox *drop)
+{
+	ID *id = (ID *)drag->poin;
+	
+	drop->opcontext = WM_OP_EXEC_DEFAULT;
+	RNA_string_set(drop->ptr, "name", id->name + 2);
+}
+
 static void view3d_id_drop_copy(wmDrag *drag, wmDropBox *drop)
 {
 	ID *id = (ID *)drag->poin;
@@ -547,6 +565,7 @@ static void view3d_dropboxes(void)
 	WM_dropbox_add(lb, "OBJECT_OT_drop_named_material", view3d_mat_drop_poll, view3d_id_drop_copy);
 	WM_dropbox_add(lb, "MESH_OT_drop_named_image", view3d_ima_ob_drop_poll, view3d_id_path_drop_copy);
 	WM_dropbox_add(lb, "VIEW3D_OT_background_image_add", view3d_ima_bg_drop_poll, view3d_id_path_drop_copy);
+	WM_dropbox_add(lb, "OBJECT_OT_group_instance_add", view3d_group_drop_poll, view3d_group_drop_copy);
 }