LibOverride: rework 'make override' 3DView operator.

Removed the 'select main object to override' menu when overriding an
instanced collection, this was no more used anyway.

Added new behavior allowing to select which directly linked collection
to override when trying to override an inderctly linked object. This
allows to link collections without instancing them with an empty object,
select one of their objects, and call override operator.

1 files changed, 69 insertions, 21 deletions

diff --git a/source/blender/editors/object/object_relations.c b/source/blender/editors/object/object_relations.c
index 7c68b41116f..945c7e87eb1 100644
--- a/source/blender/editors/object/object_relations.c
+++ b/source/blender/editors/object/object_relations.c
@@ -2293,14 +2293,9 @@ static int make_override_library_invoke(bContext *C, wmOperator *op, const wmEve
     return OPERATOR_CANCELLED;
   }
 
-  /* Get object to work on - use a menu if we need to... */
-  if (!ID_IS_LINKED(obact) && obact->instance_collection != NULL &&
-      ID_IS_LINKED(obact->instance_collection)) {
-    /* Gives menu with list of objects in group. */
-    WM_enum_search_invoke(C, op, event);
-    return OPERATOR_CANCELLED;
-  }
-  if (ID_IS_LINKED(obact)) {
+  if ((!ID_IS_LINKED(obact) && obact->instance_collection != NULL &&
+       ID_IS_OVERRIDABLE_LIBRARY(obact->instance_collection)) ||
+      ID_IS_OVERRIDABLE_LIBRARY(obact)) {
     uiPopupMenu *pup = UI_popup_menu_begin(C, IFACE_("OK?"), ICON_QUESTION);
     uiLayout *layout = UI_popup_menu_layout(pup);
 
@@ -2315,6 +2310,11 @@ static int make_override_library_invoke(bContext *C, wmOperator *op, const wmEve
     /* This invoke just calls another instance of this operator... */
     return OPERATOR_INTERFACE;
   }
+  else if (ID_IS_LINKED(obact)) {
+    /* Show menu with list of directly linked collections containing the active object. */
+    WM_enum_search_invoke(C, op, event);
+    return OPERATOR_CANCELLED;
+  }
 
   /* Error.. cannot continue. */
   BKE_report(op->reports,
@@ -2344,11 +2344,28 @@ static int make_override_library_exec(bContext *C, wmOperator *op)
     id_root = &obact->instance_collection->id;
   }
   else if (!ID_IS_OVERRIDABLE_LIBRARY(obact)) {
-    BKE_reportf(op->reports,
-                RPT_ERROR_INVALID_INPUT,
-                "Active object '%s' is not overridable",
-                obact->id.name + 2);
-    return OPERATOR_CANCELLED;
+    const int i = RNA_property_enum_get(op->ptr, op->type->prop);
+    const uint collection_session_uuid = *((uint *)&i);
+    if (collection_session_uuid == MAIN_ID_SESSION_UUID_UNSET) {
+      BKE_reportf(op->reports,
+                  RPT_ERROR_INVALID_INPUT,
+                  "Active object '%s' is not overridable",
+                  obact->id.name + 2);
+      return OPERATOR_CANCELLED;
+    }
+
+    Collection *collection = BLI_listbase_bytes_find(&bmain->collections,
+                                                     &collection_session_uuid,
+                                                     sizeof(collection_session_uuid),
+                                                     offsetof(ID, session_uuid));
+    if (!ID_IS_OVERRIDABLE_LIBRARY(collection)) {
+      BKE_reportf(op->reports,
+                  RPT_ERROR_INVALID_INPUT,
+                  "Could not find an overridable collection containing object '%s'",
+                  obact->id.name + 2);
+      return OPERATOR_CANCELLED;
+    }
+    id_root = &collection->id;
   }
   /* Else, poll func ensures us that ID_IS_LINKED(obact) is true. */
   else {
@@ -2498,9 +2515,39 @@ static bool make_override_library_poll(bContext *C)
 
   /* Object must be directly linked to be overridable. */
   return (ED_operator_objectmode(C) && obact != NULL &&
-          ((ID_IS_LINKED(obact) && obact->id.tag & LIB_TAG_EXTERN) ||
-           (!ID_IS_LINKED(obact) && obact->instance_collection != NULL &&
-            ID_IS_LINKED(obact->instance_collection))));
+          (ID_IS_LINKED(obact) || (obact->instance_collection != NULL &&
+                                   ID_IS_OVERRIDABLE_LIBRARY(obact->instance_collection))));
+}
+
+static const EnumPropertyItem *make_override_collections_of_linked_object_itemf(
+    bContext *C, PointerRNA *UNUSED(ptr), PropertyRNA *UNUSED(prop), bool *r_free)
+{
+  EnumPropertyItem item_tmp = {0}, *item = NULL;
+  int totitem = 0;
+
+  Object *object = ED_object_active_context(C);
+  Main *bmain = CTX_data_main(C);
+
+  if (!object || !ID_IS_LINKED(object)) {
+    return DummyRNA_DEFAULT_items;
+  }
+
+  LISTBASE_FOREACH (Collection *, collection, &bmain->collections) {
+    /* Only check for directly linked collections. */
+    if (!ID_IS_LINKED(&collection->id) || (collection->id.tag & LIB_TAG_INDIRECT) != 0) {
+      continue;
+    }
+    if (BKE_collection_has_object_recursive(collection, object)) {
+      item_tmp.identifier = item_tmp.name = collection->id.name + 2;
+      item_tmp.value = *((int *)&collection->id.session_uuid);
+      RNA_enum_item_add(&item, &totitem, &item_tmp);
+    }
+  }
+
+  RNA_enum_item_end(&item, &totitem);
+  *r_free = true;
+
+  return item;
 }
 
 void OBJECT_OT_make_override_library(wmOperatorType *ot)
@@ -2521,12 +2568,13 @@ void OBJECT_OT_make_override_library(wmOperatorType *ot)
   /* properties */
   PropertyRNA *prop;
   prop = RNA_def_enum(ot->srna,
-                      "object",
+                      "collection",
                       DummyRNA_DEFAULT_items,
-                      0,
-                      "Override Object",
-                      "Name of lib-linked/collection object to make an override from");
-  RNA_def_enum_funcs(prop, proxy_collection_object_itemf);
+                      MAIN_ID_SESSION_UUID_UNSET,
+                      "Override Collection",
+                      "Name of directly linked collection containing the selected object, to make "
+                      "an override from");
+  RNA_def_enum_funcs(prop, make_override_collections_of_linked_object_itemf);
   RNA_def_property_flag(prop, PROP_ENUM_NO_TRANSLATE);
   ot->prop = prop;
 }