Outliner: Collection - Duplicate Hierarchy, and Duplicate Linked Hierarchy

As per the suggestion on T57064, this introduces two new options to duplicate collections.
We then have:
* Duplicate > Collection (New collection with linked content).
* Duplicate > Hierachy (Duplicate entire hierarchy and make all contents single user).
* Duplicate > Linked Hierarchy (Duplicate entire hierarchy keeping content linked with original).

Development TODO: `single_object_users` can/should use the new functions.

Reviewers: brecht, mont29

Subscribers: pablovazquez, billreynish, JulienKaspar

Differential Revision: https://developer.blender.org/D4394

3 files changed, 38 insertions, 2 deletions

diff --git a/source/blender/editors/space_outliner/outliner_collections.c b/source/blender/editors/space_outliner/outliner_collections.c
index 67126a3e155..61c02d18f8f 100644
--- a/source/blender/editors/space_outliner/outliner_collections.c
+++ b/source/blender/editors/space_outliner/outliner_collections.c
@@ -448,6 +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 hierarchy = strstr(op->idname, "hierarchy") != NULL;
+	bool linked = strstr(op->idname, "linked") != NULL;
 
 	/* Can happen when calling from a key binding. */
 	if (te == NULL) {
@@ -467,7 +469,7 @@ static int collection_duplicate_exec(bContext *C, wmOperator *op)
 		case SO_SCENES:
 		case SO_VIEW_LAYER:
 		case SO_LIBRARIES:
-			BKE_collection_copy(bmain, parent, collection);
+			BKE_collection_duplicate(bmain, parent, collection, hierarchy, !linked);
 			break;
 	}
 
@@ -482,7 +484,37 @@ void OUTLINER_OT_collection_duplicate(wmOperatorType *ot)
 	/* identifiers */
 	ot->name = "Duplicate Collection";
 	ot->idname = "OUTLINER_OT_collection_duplicate";
-	ot->description = "Duplicate selected collections";
+	ot->description = "Make a new collection with linked content (collection and objects)";
+
+	/* 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_hierarchy(wmOperatorType *ot)
+{
+	/* identifiers */
+	ot->name = "Duplicate Collection Hierarchy";
+	ot->idname = "OUTLINER_OT_collection_duplicate_hierarchy";
+	ot->description = "Duplicate entire hierarchy and make all content single user";
+
+	/* 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_linked_hierarchy(wmOperatorType *ot)
+{
+	/* identifiers */
+	ot->name = "Duplicate Linked Collection Hierarchy";
+	ot->idname = "OUTLINER_OT_collection_duplicate_linked_hierarchy";
+	ot->description = "Duplicate entire hierarchy with linked 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 81b06cab3a1..a1751e90660 100644
--- a/source/blender/editors/space_outliner/outliner_intern.h
+++ b/source/blender/editors/space_outliner/outliner_intern.h
@@ -316,6 +316,8 @@ 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_hierarchy(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 81001c0160f..404ad17ba4e 100644
--- a/source/blender/editors/space_outliner/outliner_ops.c
+++ b/source/blender/editors/space_outliner/outliner_ops.c
@@ -94,6 +94,8 @@ 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_hierarchy);
 	WM_operatortype_append(OUTLINER_OT_collection_delete);
 	WM_operatortype_append(OUTLINER_OT_collection_objects_select);
 	WM_operatortype_append(OUTLINER_OT_collection_objects_deselect);