Collection duplication from Outliner: add a 'duplicate hierarchy' operation.

Point is, you may want to duplicate your set of collections, but not
duplicate all their objects.

Some notes:
* Am rather skeptical about the practice of using operator name to
define behavior of some common exec code. Imho, that should be a single
operator with an enum to refine its behavior (@cambpellbarton may also
have an opinion here?). Left it as-is for now, because this seems to be
used by other operators too in that code. :/
* @dfelinto, @pablovazquez, @billreynish am not so happy with current
names, but cannot find really good short ones either... Also, shouldn't
we move those into a dedicated `Duplicate` sub-menu?

3 files changed, 27 insertions, 9 deletions

diff --git a/source/blender/editors/space_outliner/outliner_collections.c b/source/blender/editors/space_outliner/outliner_collections.c
index 750c78d76b9..7403525c293 100644
--- a/source/blender/editors/space_outliner/outliner_collections.c
+++ b/source/blender/editors/space_outliner/outliner_collections.c
@@ -448,7 +448,8 @@ static int collection_duplicate_exec(bContext *C, wmOperator *op)
 	Main *bmain = CTX_data_main(C);
 	SpaceOutliner *soops = CTX_wm_space_outliner(C);
 	TreeElement *te = outliner_active_collection(C);
-	bool linked = strstr(op->idname, "linked") != NULL;
+	const bool hierarchy = strstr(op->idname, "hierarchy") != NULL;
+	const bool linked = strstr(op->idname, "linked") != NULL;
 
 	/* Can happen when calling from a key binding. */
 	if (te == NULL) {
@@ -468,7 +469,7 @@ static int collection_duplicate_exec(bContext *C, wmOperator *op)
 		case SO_SCENES:
 		case SO_VIEW_LAYER:
 		case SO_LIBRARIES:
-			BKE_collection_duplicate(bmain, parent, collection, true, !linked);
+			BKE_collection_duplicate(bmain, parent, collection, true, !hierarchy, !linked);
 			break;
 	}
 
@@ -478,12 +479,12 @@ static int collection_duplicate_exec(bContext *C, wmOperator *op)
 	return OPERATOR_FINISHED;
 }
 
-void OUTLINER_OT_collection_duplicate(wmOperatorType *ot)
+void OUTLINER_OT_collection_duplicate_hierarchy(wmOperatorType *ot)
 {
 	/* identifiers */
-	ot->name = "Duplicate Collection";
-	ot->idname = "OUTLINER_OT_collection_duplicate";
-	ot->description = "Duplicate all objects and collections and make them single user";
+	ot->name = "Duplicate Collection Hierarchy";
+	ot->idname = "OUTLINER_OT_collection_duplicate_hierarchy";
+	ot->description = "Recursively duplicate the collection and all its children, with linked objects";
 
 	/* api callbacks */
 	ot->exec = collection_duplicate_exec;
@@ -498,7 +499,22 @@ void OUTLINER_OT_collection_duplicate_linked(wmOperatorType *ot)
 	/* identifiers */
 	ot->name = "Duplicate Linked Collection";
 	ot->idname = "OUTLINER_OT_collection_duplicate_linked";
-	ot->description = "Duplicate all objects and collections with linked object data";
+	ot->description = "Recursively duplicate the collection, all its children and objects, with linked object data";
+
+	/* api callbacks */
+	ot->exec = collection_duplicate_exec;
+	ot->poll = ED_outliner_collections_editor_poll;
+
+	/* flags */
+	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
+}
+
+void OUTLINER_OT_collection_duplicate(wmOperatorType *ot)
+{
+	/* identifiers */
+	ot->name = "Duplicate Collection";
+	ot->idname = "OUTLINER_OT_collection_duplicate";
+	ot->description = "Recursively duplicate the collection, all its children, objects and object data";
 
 	/* api callbacks */
 	ot->exec = collection_duplicate_exec;
diff --git a/source/blender/editors/space_outliner/outliner_intern.h b/source/blender/editors/space_outliner/outliner_intern.h
index 0851d5ce9f4..5af8e2252ef 100644
--- a/source/blender/editors/space_outliner/outliner_intern.h
+++ b/source/blender/editors/space_outliner/outliner_intern.h
@@ -315,8 +315,9 @@ bool outliner_is_collection_tree_element(const TreeElement *te);
 struct Collection *outliner_collection_from_tree_element(const TreeElement *te);
 
 void OUTLINER_OT_collection_new(struct wmOperatorType *ot);
-void OUTLINER_OT_collection_duplicate(struct wmOperatorType *ot);
+void OUTLINER_OT_collection_duplicate_hierarchy(struct wmOperatorType *ot);
 void OUTLINER_OT_collection_duplicate_linked(struct wmOperatorType *ot);
+void OUTLINER_OT_collection_duplicate(struct wmOperatorType *ot);
 void OUTLINER_OT_collection_delete(struct wmOperatorType *ot);
 void OUTLINER_OT_collection_objects_select(struct wmOperatorType *ot);
 void OUTLINER_OT_collection_objects_deselect(struct wmOperatorType *ot);
diff --git a/source/blender/editors/space_outliner/outliner_ops.c b/source/blender/editors/space_outliner/outliner_ops.c
index eea06fc0b0c..af73e88aa73 100644
--- a/source/blender/editors/space_outliner/outliner_ops.c
+++ b/source/blender/editors/space_outliner/outliner_ops.c
@@ -93,8 +93,9 @@ void outliner_operatortypes(void)
 
 	/* collections */
 	WM_operatortype_append(OUTLINER_OT_collection_new);
-	WM_operatortype_append(OUTLINER_OT_collection_duplicate);
+	WM_operatortype_append(OUTLINER_OT_collection_duplicate_hierarchy);
 	WM_operatortype_append(OUTLINER_OT_collection_duplicate_linked);
+	WM_operatortype_append(OUTLINER_OT_collection_duplicate);
 	WM_operatortype_append(OUTLINER_OT_collection_delete);
 	WM_operatortype_append(OUTLINER_OT_collection_objects_select);
 	WM_operatortype_append(OUTLINER_OT_collection_objects_deselect);