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

18 files changed, 70 insertions, 150 deletions

diff --git a/source/blender/makesrna/RNA_access.h b/source/blender/makesrna/RNA_access.h
index 782d0924d21..299f96a4c46 100644
--- a/source/blender/makesrna/RNA_access.h
+++ b/source/blender/makesrna/RNA_access.h
@@ -811,6 +811,7 @@ void RNA_struct_py_type_set(StructRNA *srna, void *py_type);
 void *RNA_struct_blender_type_get(StructRNA *srna);
 void RNA_struct_blender_type_set(StructRNA *srna, void *blender_type);
 
+struct IDProperty **RNA_struct_idprops_p(PointerRNA *ptr);
 struct IDProperty *RNA_struct_idprops(PointerRNA *ptr, bool create);
 bool RNA_struct_idprops_check(StructRNA *srna);
 bool RNA_struct_idprops_register_check(const StructRNA *type);
diff --git a/source/blender/makesrna/intern/rna_ID.c b/source/blender/makesrna/intern/rna_ID.c
index 694636f0c94..38b00afdc8f 100644
--- a/source/blender/makesrna/intern/rna_ID.c
+++ b/source/blender/makesrna/intern/rna_ID.c
@@ -493,9 +493,10 @@ StructRNA *rna_ID_refine(PointerRNA *ptr)
   return ID_code_to_RNA_type(GS(id->name));
 }
 
-IDProperty *rna_ID_idprops(PointerRNA *ptr, bool create)
+IDProperty **rna_ID_idprops(PointerRNA *ptr)
 {
-  return IDP_GetProperties(ptr->data, create);
+  ID *id = (ID *)ptr->data;
+  return &id->properties;
 }
 
 void rna_ID_fake_user_set(PointerRNA *ptr, bool value)
@@ -510,9 +511,9 @@ void rna_ID_fake_user_set(PointerRNA *ptr, bool value)
   }
 }
 
-IDProperty *rna_PropertyGroup_idprops(PointerRNA *ptr, bool UNUSED(create))
+IDProperty **rna_PropertyGroup_idprops(PointerRNA *ptr)
 {
-  return ptr->data;
+  return (IDProperty **)&ptr->data;
 }
 
 void rna_PropertyGroup_unregister(Main *UNUSED(bmain), StructRNA *type)
@@ -1162,12 +1163,12 @@ static PointerRNA rna_IDPreview_get(PointerRNA *ptr)
   return rna_pointer_inherit_refine(ptr, &RNA_ImagePreview, prv_img);
 }
 
-static IDProperty *rna_IDPropertyWrapPtr_idprops(PointerRNA *ptr, bool UNUSED(create))
+static IDProperty **rna_IDPropertyWrapPtr_idprops(PointerRNA *ptr)
 {
   if (ptr == NULL) {
     return NULL;
   }
-  return ptr->data;
+  return (IDProperty **)&ptr->data;
 }
 
 static void rna_Library_version_get(PointerRNA *ptr, int *value)
diff --git a/source/blender/makesrna/intern/rna_access.c b/source/blender/makesrna/intern/rna_access.c
index b4d0fcdee31..eb347987f87 100644
--- a/source/blender/makesrna/intern/rna_access.c
+++ b/source/blender/makesrna/intern/rna_access.c
@@ -369,15 +369,32 @@ static bool rna_idproperty_ui_set_default(PointerRNA *ptr,
   return true;
 }
 
-IDProperty *RNA_struct_idprops(PointerRNA *ptr, bool create)
+IDProperty **RNA_struct_idprops_p(PointerRNA *ptr)
 {
   StructRNA *type = ptr->type;
+  if (type == NULL) {
+    return NULL;
+  }
+  if (type->idproperties == NULL) {
+    return NULL;
+  }
+
+  return type->idproperties(ptr);
+}
 
-  if (type && type->idproperties) {
-    return type->idproperties(ptr, create);
+IDProperty *RNA_struct_idprops(PointerRNA *ptr, bool create)
+{
+  IDProperty **property_ptr = RNA_struct_idprops_p(ptr);
+  if (property_ptr == NULL) {
+    return NULL;
   }
 
-  return NULL;
+  if (create && *property_ptr == NULL) {
+    IDPropertyTemplate val = {0};
+    *property_ptr = IDP_New(IDP_GROUP, &val, __func__);
+  }
+
+  return *property_ptr;
 }
 
 bool RNA_struct_idprops_check(StructRNA *srna)
diff --git a/source/blender/makesrna/intern/rna_armature.c b/source/blender/makesrna/intern/rna_armature.c
index 7114e21beff..49d02524e43 100644
--- a/source/blender/makesrna/intern/rna_armature.c
+++ b/source/blender/makesrna/intern/rna_armature.c
@@ -260,28 +260,16 @@ static char *rna_Bone_path(PointerRNA *ptr)
   return BLI_sprintfN("bones[\"%s\"]", name_esc);
 }
 
-static IDProperty *rna_Bone_idprops(PointerRNA *ptr, bool create)
+static IDProperty **rna_Bone_idprops(PointerRNA *ptr)
 {
   Bone *bone = ptr->data;
-
-  if (create && !bone->prop) {
-    IDPropertyTemplate val = {0};
-    bone->prop = IDP_New(IDP_GROUP, &val, "RNA_Bone ID properties");
-  }
-
-  return bone->prop;
+  return &bone->prop;
 }
 
-static IDProperty *rna_EditBone_idprops(PointerRNA *ptr, bool create)
+static IDProperty **rna_EditBone_idprops(PointerRNA *ptr)
 {
   EditBone *ebone = ptr->data;
-
-  if (create && !ebone->prop) {
-    IDPropertyTemplate val = {0};
-    ebone->prop = IDP_New(IDP_GROUP, &val, "RNA_EditBone ID properties");
-  }
-
-  return ebone->prop;
+  return &ebone->prop;
 }
 
 static void rna_bone_layer_set(int *layer, const bool *values)
diff --git a/source/blender/makesrna/intern/rna_asset.c b/source/blender/makesrna/intern/rna_asset.c
index 1af53e95cc9..55f680c736d 100644
--- a/source/blender/makesrna/intern/rna_asset.c
+++ b/source/blender/makesrna/intern/rna_asset.c
@@ -75,16 +75,10 @@ static void rna_AssetMetaData_tag_remove(AssetMetaData *asset_data,
   RNA_POINTER_INVALIDATE(tag_ptr);
 }
 
-static IDProperty *rna_AssetMetaData_idprops(PointerRNA *ptr, bool create)
+static IDProperty **rna_AssetMetaData_idprops(PointerRNA *ptr)
 {
   AssetMetaData *asset_data = ptr->data;
-
-  if (create && !asset_data->properties) {
-    IDPropertyTemplate val = {0};
-    asset_data->properties = IDP_New(IDP_GROUP, &val, "RNA_AssetMetaData group");
-  }
-
-  return asset_data->properties;
+  return &asset_data->properties;
 }
 
 static void rna_AssetMetaData_description_get(PointerRNA *ptr, char *value)
diff --git a/source/blender/makesrna/intern/rna_internal.h b/source/blender/makesrna/intern/rna_internal.h
index bfe9d4bb77c..f15368bcc77 100644
--- a/source/blender/makesrna/intern/rna_internal.h
+++ b/source/blender/makesrna/intern/rna_internal.h
@@ -276,10 +276,10 @@ void rna_ID_name_get(struct PointerRNA *ptr, char *value);
 int rna_ID_name_length(struct PointerRNA *ptr);
 void rna_ID_name_set(struct PointerRNA *ptr, const char *value);
 struct StructRNA *rna_ID_refine(struct PointerRNA *ptr);
-struct IDProperty *rna_ID_idprops(struct PointerRNA *ptr, bool create);
+struct IDProperty **rna_ID_idprops(struct PointerRNA *ptr);
 void rna_ID_fake_user_set(struct PointerRNA *ptr, bool value);
 void **rna_ID_instance(PointerRNA *ptr);
-struct IDProperty *rna_PropertyGroup_idprops(struct PointerRNA *ptr, bool create);
+struct IDProperty **rna_PropertyGroup_idprops(struct PointerRNA *ptr);
 void rna_PropertyGroup_unregister(struct Main *bmain, struct StructRNA *type);
 struct StructRNA *rna_PropertyGroup_register(struct Main *bmain,
                                              struct ReportList *reports,
diff --git a/source/blender/makesrna/intern/rna_internal_types.h b/source/blender/makesrna/intern/rna_internal_types.h
index ee60b199d64..479306e8c06 100644
--- a/source/blender/makesrna/intern/rna_internal_types.h
+++ b/source/blender/makesrna/intern/rna_internal_types.h
@@ -54,7 +54,7 @@ typedef void (*ContextPropUpdateFunc)(struct bContext *C,
 typedef void (*ContextUpdateFunc)(struct bContext *C, struct PointerRNA *ptr);
 typedef int (*EditableFunc)(struct PointerRNA *ptr, const char **r_info);
 typedef int (*ItemEditableFunc)(struct PointerRNA *ptr, int index);
-typedef struct IDProperty *(*IDPropertiesFunc)(struct PointerRNA *ptr, bool create);
+typedef struct IDProperty **(*IDPropertiesFunc)(struct PointerRNA *ptr);
 typedef struct StructRNA *(*StructRefineFunc)(struct PointerRNA *ptr);
 typedef char *(*StructPathFunc)(struct PointerRNA *ptr);
 
@@ -559,7 +559,7 @@ struct StructRNA {
    */
   StructInstanceFunc instance;
 
-  /* callback to get id properties */
+  /** Return the location of the struct's pointer to the root group IDProperty. */
   IDPropertiesFunc idproperties;
 
   /* functions of this struct */
diff --git a/source/blender/makesrna/intern/rna_layer.c b/source/blender/makesrna/intern/rna_layer.c
index b4253ab9236..0414afe1514 100644
--- a/source/blender/makesrna/intern/rna_layer.c
+++ b/source/blender/makesrna/intern/rna_layer.c
@@ -119,16 +119,10 @@ static char *rna_ViewLayer_path(PointerRNA *ptr)
   return BLI_sprintfN("view_layers[\"%s\"]", name_esc);
 }
 
-static IDProperty *rna_ViewLayer_idprops(PointerRNA *ptr, bool create)
+static IDProperty **rna_ViewLayer_idprops(PointerRNA *ptr)
 {
   ViewLayer *view_layer = (ViewLayer *)ptr->data;
-
-  if (create && !view_layer->id_properties) {
-    IDPropertyTemplate val = {0};
-    view_layer->id_properties = IDP_New(IDP_GROUP, &val, "ViewLayer ID properties");
-  }
-
-  return view_layer->id_properties;
+  return &view_layer->id_properties;
 }
 
 static bool rna_LayerCollection_visible_get(LayerCollection *layer_collection, bContext *C)
diff --git a/source/blender/makesrna/intern/rna_modifier.c b/source/blender/makesrna/intern/rna_modifier.c
index ca219e83fc2..e64eaf8c363 100644
--- a/source/blender/makesrna/intern/rna_modifier.c
+++ b/source/blender/makesrna/intern/rna_modifier.c
@@ -1621,15 +1621,11 @@ static void rna_NodesModifier_node_group_update(Main *bmain, Scene *scene, Point
   MOD_nodes_update_interface(object, nmd);
 }
 
-static IDProperty *rna_NodesModifier_properties(PointerRNA *ptr, bool create)
+static IDProperty **rna_NodesModifier_properties(PointerRNA *ptr)
 {
   NodesModifierData *nmd = ptr->data;
   NodesModifierSettings *settings = &nmd->settings;
-  if (create && settings->properties == NULL) {
-    IDPropertyTemplate val = {0};
-    settings->properties = IDP_New(IDP_GROUP, &val, "Nodes Modifier Settings");
-  }
-  return settings->properties;
+  return &settings->properties;
 }
 #else
 
diff --git a/source/blender/makesrna/intern/rna_nodetree.c b/source/blender/makesrna/intern/rna_nodetree.c
index d576a5b7db6..cfd83a85d2e 100644
--- a/source/blender/makesrna/intern/rna_nodetree.c
+++ b/source/blender/makesrna/intern/rna_nodetree.c
@@ -2366,16 +2366,10 @@ static StructRNA *rna_FunctionNode_register(Main *bmain,
   return nt->rna_ext.srna;
 }
 
-static IDProperty *rna_Node_idprops(PointerRNA *ptr, bool create)
+static IDProperty **rna_Node_idprops(PointerRNA *ptr)
 {
   bNode *node = ptr->data;
-
-  if (create && !node->prop) {
-    IDPropertyTemplate val = {0};
-    node->prop = IDP_New(IDP_GROUP, &val, "RNA_Node ID properties");
-  }
-
-  return node->prop;
+  return &node->prop;
 }
 
 static void rna_Node_parent_set(PointerRNA *ptr,
@@ -2834,16 +2828,10 @@ static char *rna_NodeSocket_path(PointerRNA *ptr)
   }
 }
 
-static IDProperty *rna_NodeSocket_idprops(PointerRNA *ptr, bool create)
+static IDProperty **rna_NodeSocket_idprops(PointerRNA *ptr)
 {
   bNodeSocket *sock = ptr->data;
-
-  if (create && !sock->prop) {
-    IDPropertyTemplate val = {0};
-    sock->prop = IDP_New(IDP_GROUP, &val, "RNA_NodeSocket ID properties");
-  }
-
-  return sock->prop;
+  return &sock->prop;
 }
 
 static PointerRNA rna_NodeSocket_node_get(PointerRNA *ptr)
@@ -3150,16 +3138,10 @@ static char *rna_NodeSocketInterface_path(PointerRNA *ptr)
   return NULL;
 }
 
-static IDProperty *rna_NodeSocketInterface_idprops(PointerRNA *ptr, bool create)
+static IDProperty **rna_NodeSocketInterface_idprops(PointerRNA *ptr)
 {
   bNodeSocket *sock = ptr->data;
-
-  if (create && !sock->prop) {
-    IDPropertyTemplate val = {0};
-    sock->prop = IDP_New(IDP_GROUP, &val, "RNA_NodeSocketInterface ID properties");
-  }
-
-  return sock->prop;
+  return &sock->prop;
 }
 
 static void rna_NodeSocketInterface_update(Main *bmain, Scene *UNUSED(scene), PointerRNA *ptr)
@@ -9950,7 +9932,7 @@ static void def_geo_switch(StructRNA *srna)
 static void def_geo_curve_primitive_quadrilateral(StructRNA *srna)
 {
   PropertyRNA *prop;
-  
+
   static EnumPropertyItem mode_items[] = {
       {GEO_NODE_CURVE_PRIMITIVE_QUAD_MODE_RECTANGLE,
        "RECTANGLE",
diff --git a/source/blender/makesrna/intern/rna_pose.c b/source/blender/makesrna/intern/rna_pose.c
index bb4939a010b..ee509fa92d4 100644
--- a/source/blender/makesrna/intern/rna_pose.c
+++ b/source/blender/makesrna/intern/rna_pose.c
@@ -224,16 +224,10 @@ static void rna_BoneGroup_name_set(PointerRNA *ptr, const char *value)
                  sizeof(agrp->name));
 }
 
-static IDProperty *rna_PoseBone_idprops(PointerRNA *ptr, bool create)
+static IDProperty **rna_PoseBone_idprops(PointerRNA *ptr)
 {
   bPoseChannel *pchan = ptr->data;
-
-  if (create && !pchan->prop) {
-    IDPropertyTemplate val = {0};
-    pchan->prop = IDP_New(IDP_GROUP, &val, "RNA_PoseBone group");
-  }
-
-  return pchan->prop;
+  return &pchan->prop;
 }
 
 static void rna_Pose_ik_solver_set(struct PointerRNA *ptr, int value)
diff --git a/source/blender/makesrna/intern/rna_sequencer.c b/source/blender/makesrna/intern/rna_sequencer.c
index 5f6456d3d1e..b1f0b0d760f 100644
--- a/source/blender/makesrna/intern/rna_sequencer.c
+++ b/source/blender/makesrna/intern/rna_sequencer.c
@@ -734,16 +734,10 @@ static char *rna_Sequence_path(PointerRNA *ptr)
   }
 }
 
-static IDProperty *rna_Sequence_idprops(PointerRNA *ptr, bool create)
+static IDProperty **rna_Sequence_idprops(PointerRNA *ptr)
 {
   Sequence *seq = ptr->data;
-
-  if (create && !seq->prop) {
-    IDPropertyTemplate val = {0};
-    seq->prop = IDP_New(IDP_GROUP, &val, "Sequence ID properties");
-  }
-
-  return seq->prop;
+  return &seq->prop;
 }
 
 static bool rna_MovieSequence_reload_if_needed(ID *scene_id, Sequence *seq, Main *bmain)
diff --git a/source/blender/makesrna/intern/rna_space.c b/source/blender/makesrna/intern/rna_space.c
index 11110dd154a..7366934695e 100644
--- a/source/blender/makesrna/intern/rna_space.c
+++ b/source/blender/makesrna/intern/rna_space.c
@@ -1041,16 +1041,10 @@ static bool rna_RegionView3D_is_orthographic_side_view_get(PointerRNA *ptr)
   return RV3D_VIEW_IS_AXIS(rv3d->view);
 }
 
-static IDProperty *rna_View3DShading_idprops(PointerRNA *ptr, bool create)
+static IDProperty **rna_View3DShading_idprops(PointerRNA *ptr)
 {
   View3DShading *shading = ptr->data;
-
-  if (create && !shading->prop) {
-    IDPropertyTemplate val = {0};
-    shading->prop = IDP_New(IDP_GROUP, &val, "View3DShading ID properties");
-  }
-
-  return shading->prop;
+  return &shading->prop;
 }
 
 static void rna_3DViewShading_type_update(Main *bmain, Scene *scene, PointerRNA *ptr)
diff --git a/source/blender/makesrna/intern/rna_timeline.c b/source/blender/makesrna/intern/rna_timeline.c
index c0bd9fd92a2..223e6389942 100644
--- a/source/blender/makesrna/intern/rna_timeline.c
+++ b/source/blender/makesrna/intern/rna_timeline.c
@@ -33,16 +33,10 @@
 #  include "BKE_idprop.h"
 #  include "WM_api.h"
 
-static IDProperty *rna_TimelineMarker_idprops(PointerRNA *ptr, bool create)
+static IDProperty **rna_TimelineMarker_idprops(PointerRNA *ptr)
 {
   TimeMarker *marker = ptr->data;
-
-  if (create && marker->prop == NULL) {
-    IDPropertyTemplate val = {0};
-    marker->prop = IDP_New(IDP_GROUP, &val, "Marker ID properties");
-  }
-
-  return marker->prop;
+  return &marker->prop;
 }
 
 static void rna_TimelineMarker_update(Main *UNUSED(bmain),
diff --git a/source/blender/makesrna/intern/rna_ui.c b/source/blender/makesrna/intern/rna_ui.c
index 98bed5a7891..d4ae5f1ecfc 100644
--- a/source/blender/makesrna/intern/rna_ui.c
+++ b/source/blender/makesrna/intern/rna_ui.c
@@ -452,15 +452,10 @@ static unsigned int rna_UIList_filter_const_FILTER_ITEM_get(PointerRNA *UNUSED(p
   return UILST_FLT_ITEM;
 }
 
-static IDProperty *rna_UIList_idprops(PointerRNA *ptr, bool create)
+static IDProperty **rna_UIList_idprops(PointerRNA *ptr)
 {
   uiList *ui_list = (uiList *)ptr->data;
-  if (create && !ui_list->properties) {
-    IDPropertyTemplate val = {0};
-    ui_list->properties = IDP_New(IDP_GROUP, &val, "RNA_UIList IDproperties group");
-  }
-
-  return ui_list->properties;
+  return &ui_list->properties;
 }
 
 static void uilist_draw_item(uiList *ui_list,
diff --git a/source/blender/makesrna/intern/rna_userdef.c b/source/blender/makesrna/intern/rna_userdef.c
index 81f6bcc5805..fd1c0b7951a 100644
--- a/source/blender/makesrna/intern/rna_userdef.c
+++ b/source/blender/makesrna/intern/rna_userdef.c
@@ -809,14 +809,9 @@ static const EnumPropertyItem *rna_lang_enum_properties_itemf(bContext *UNUSED(C
 }
 #  endif
 
-static IDProperty *rna_AddonPref_idprops(PointerRNA *ptr, bool create)
+static IDProperty **rna_AddonPref_idprops(PointerRNA *ptr)
 {
-  if (create && !ptr->data) {
-    IDPropertyTemplate val = {0};
-    ptr->data = IDP_New(IDP_GROUP, &val, "RNA_AddonPreferences group");
-  }
-
-  return ptr->data;
+  return (IDProperty **)&ptr->data;
 }
 
 static PointerRNA rna_Addon_preferences_get(PointerRNA *ptr)
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)
diff --git a/source/blender/makesrna/intern/rna_wm_gizmo.c b/source/blender/makesrna/intern/rna_wm_gizmo.c
index 98920bbd518..076a77d4fb5 100644
--- a/source/blender/makesrna/intern/rna_wm_gizmo.c
+++ b/source/blender/makesrna/intern/rna_wm_gizmo.c
@@ -293,14 +293,9 @@ static StructRNA *rna_GizmoProperties_refine(PointerRNA *ptr)
   }
 }
 
-static IDProperty *rna_GizmoProperties_idprops(PointerRNA *ptr, bool create)
+static IDProperty **rna_GizmoProperties_idprops(PointerRNA *ptr)
 {
-  if (create && !ptr->data) {
-    IDPropertyTemplate val = {0};
-    ptr->data = IDP_New(IDP_GROUP, &val, "RNA_GizmoProperties group");
-  }
-
-  return ptr->data;
+  return (IDProperty **)&ptr->data;
 }
 
 static PointerRNA rna_Gizmo_properties_get(PointerRNA *ptr)
@@ -585,14 +580,9 @@ static StructRNA *rna_GizmoGroupProperties_refine(PointerRNA *ptr)
   }
 }
 
-static IDProperty *rna_GizmoGroupProperties_idprops(PointerRNA *ptr, bool create)
+static IDProperty **rna_GizmoGroupProperties_idprops(PointerRNA *ptr)
 {
-  if (create && !ptr->data) {
-    IDPropertyTemplate val = {0};
-    ptr->data = IDP_New(IDP_GROUP, &val, "RNA_GizmoGroupProperties group");
-  }
-
-  return ptr->data;
+  return (IDProperty **)&ptr->data;
 }
 
 static wmGizmo *rna_GizmoGroup_gizmo_new(wmGizmoGroup *gzgroup,