LibOverride: Implement default 'user override' behavior.

Implement default behavior to decide which overrides remain 'system'
ones, and which become 'user editable' ones, when creating hierarchy
override from 3DView or the Outliner.

3DView:
If from an Empty-instanced collection, only Armature objects in
that collection are user overrides.
If from a set of selected objects, all overrides created from selected
objects are user overrides.

Outliner:
All override IDs created from selected elements in the Outliner are user
overrides.
There is one special case: When a collection is selected, and is
'closed' in the outliner, all its inner armature objects are also user
overrides.

Ref: {T95707}.

1 files changed, 43 insertions, 1 deletions

diff --git a/source/blender/editors/object/object_relations.c b/source/blender/editors/object/object_relations.c
index 3ecf86d14ed..70081b4b5f2 100644
--- a/source/blender/editors/object/object_relations.c
+++ b/source/blender/editors/object/object_relations.c
@@ -2273,6 +2273,10 @@ static int make_override_library_exec(bContext *C, wmOperator *op)
   ID *id_root = NULL;
   bool is_override_instancing_object = false;
 
+  GSet *user_overrides_objects_uids = BLI_gset_new(
+      BLI_ghashutil_inthash_p, BLI_ghashutil_intcmp, __func__);
+  bool user_overrides_from_selected_objects = false;
+
   if (!ID_IS_LINKED(obact) && obact->instance_collection != NULL &&
       ID_IS_LINKED(obact->instance_collection)) {
     if (!ID_IS_OVERRIDABLE_LIBRARY(obact->instance_collection)) {
@@ -2285,6 +2289,7 @@ static int make_override_library_exec(bContext *C, wmOperator *op)
 
     id_root = &obact->instance_collection->id;
     is_override_instancing_object = true;
+    user_overrides_from_selected_objects = false;
   }
   else if (!make_override_library_object_overridable_check(bmain, obact)) {
     const int i = RNA_property_enum_get(op->ptr, op->type->prop);
@@ -2309,16 +2314,53 @@ static int make_override_library_exec(bContext *C, wmOperator *op)
       return OPERATOR_CANCELLED;
     }
     id_root = &collection->id;
+    user_overrides_from_selected_objects = true;
   }
   /* Else, poll func ensures us that ID_IS_LINKED(obact) is true. */
   else {
     id_root = &obact->id;
+    user_overrides_from_selected_objects = true;
+  }
+
+  if (user_overrides_from_selected_objects) {
+    /* Only selected objects can be 'user overrides'. */
+    FOREACH_SELECTED_OBJECT_BEGIN (view_layer, CTX_wm_view3d(C), ob_iter) {
+      BLI_gset_add(user_overrides_objects_uids, POINTER_FROM_UINT(ob_iter->id.session_uuid));
+    }
+    FOREACH_SELECTED_OBJECT_END;
+  }
+  else {
+    /* Only armatures inside the root collection (and their children) can be 'user overrides'. */
+    FOREACH_COLLECTION_OBJECT_RECURSIVE_BEGIN ((Collection *)id_root, ob_iter) {
+      if (ob_iter->type == OB_ARMATURE) {
+        BLI_gset_add(user_overrides_objects_uids, POINTER_FROM_UINT(ob_iter->id.session_uuid));
+      }
+    }
+    FOREACH_COLLECTION_OBJECT_RECURSIVE_END;
   }
 
   BKE_main_id_tag_all(bmain, LIB_TAG_DOIT, false);
 
+  ID *id_root_override;
   const bool success = BKE_lib_override_library_create(
-      bmain, scene, view_layer, NULL, id_root, id_root, &obact->id, NULL);
+      bmain, scene, view_layer, NULL, id_root, id_root, &obact->id, &id_root_override);
+
+  /* Define liboverrides from selected/validated objects as user defined. */
+  ID *id_hierarchy_root_override = id_root_override->override_library->hierarchy_root;
+  ID *id_iter;
+  FOREACH_MAIN_ID_BEGIN (bmain, id_iter) {
+    if (ID_IS_LINKED(id_iter) || !ID_IS_OVERRIDE_LIBRARY_REAL(id_iter) ||
+        id_iter->override_library->hierarchy_root != id_hierarchy_root_override) {
+      continue;
+    }
+    if (BLI_gset_haskey(user_overrides_objects_uids,
+                        POINTER_FROM_UINT(id_iter->override_library->reference->session_uuid))) {
+      id_iter->override_library->flag &= ~IDOVERRIDE_LIBRARY_FLAG_SYSTEM_DEFINED;
+    }
+  }
+  FOREACH_MAIN_ID_END;
+
+  BLI_gset_free(user_overrides_objects_uids, NULL);
 
   /* Remove the instance empty from this scene, the items now have an overridden collection
    * instead. */