Python API: Add functions to ensure and clear IDProperties

This adds id_properties_clear() and id_properties_ensure() functions
to RNA structs. This is meant as an initial change based on discussion
in review of D9697. However, they may be useful in other situations.

The change requires refactoring the internal idproperties callback to
return a pointer to the IDProperty pointer, which actually turns out
to be quite a nice cleanup.

An id_properties attribute could be added in the future potentially.

Differential Revision: https://developer.blender.org/D11908

1 files changed, 4 insertions, 13 deletions

diff --git a/source/blender/makesrna/intern/rna_wm.c b/source/blender/makesrna/intern/rna_wm.c
index a563541b968..afbde26e59e 100644
--- a/source/blender/makesrna/intern/rna_wm.c
+++ b/source/blender/makesrna/intern/rna_wm.c
@@ -568,14 +568,9 @@ static StructRNA *rna_OperatorProperties_refine(PointerRNA *ptr)
   }
 }
 
-static IDProperty *rna_OperatorProperties_idprops(PointerRNA *ptr, bool create)
+static IDProperty **rna_OperatorProperties_idprops(PointerRNA *ptr)
 {
-  if (create && !ptr->data) {
-    IDPropertyTemplate val = {0};
-    ptr->data = IDP_New(IDP_GROUP, &val, "RNA_OperatorProperties group");
-  }
-
-  return ptr->data;
+  return (IDProperty **)&ptr->data;
 }
 
 static void rna_Operator_name_get(PointerRNA *ptr, char *value)
@@ -1120,13 +1115,9 @@ static PointerRNA rna_wmKeyConfig_preferences_get(PointerRNA *ptr)
   }
 }
 
-static IDProperty *rna_wmKeyConfigPref_idprops(PointerRNA *ptr, bool create)
+static IDProperty **rna_wmKeyConfigPref_idprops(PointerRNA *ptr)
 {
-  if (create && !ptr->data) {
-    IDPropertyTemplate val = {0};
-    ptr->data = IDP_New(IDP_GROUP, &val, "RNA_KeyConfigPreferences group");
-  }
-  return ptr->data;
+  return (IDProperty **)&ptr->data;
 }
 
 static void rna_wmKeyConfigPref_unregister(Main *UNUSED(bmain), StructRNA *type)