RNA: Allow structs to define tags for their properties

Adds support for defining a number of tags as part of the rna-struct
definition, which its properties can set similar to property-flags.
BPY supports setting these tags when defining custom properties too.

* To define tags for a struct (which its properties can use then), define the tags in an `EnumPropertyItem` array, and assign them to the struct using `RNA_def_struct_property_tags(...)`.
* To set tags for an RNA-property in C, use the new `RNA_def_property_tags(...)`.
* To set tags for an RNA-property in Python, use the newly added tags parameter. E.g. `bpy.props.FloatProperty(name="Some Float", tags={'SOME_TAG', 'ANOTHER_TAG'})`.

Actual usage of this will be added in a follow-up commit.

1 files changed, 28 insertions, 0 deletions

diff --git a/source/blender/makesrna/intern/rna_access.c b/source/blender/makesrna/intern/rna_access.c
index d088a7c23e6..4aebcbb0aaf 100644
--- a/source/blender/makesrna/intern/rna_access.c
+++ b/source/blender/makesrna/intern/rna_access.c
@@ -566,6 +566,11 @@ PropertyRNA *RNA_struct_name_property(const StructRNA *type)
 	return type->nameproperty;
 }
 
+const EnumPropertyItem *RNA_struct_property_tag_defines(const StructRNA *type)
+{
+	return type->prop_tag_defines;
+}
+
 PropertyRNA *RNA_struct_iterator_property(StructRNA *type)
 {
 	return type->iteratorproperty;
@@ -947,6 +952,17 @@ int RNA_property_flag(PropertyRNA *prop)
 	return rna_ensure_property(prop)->flag;
 }
 
+/**
+ * Get the tags set for \a prop as int bitfield.
+ * \note Doesn't perform any validity check on the set bits. #RNA_def_property_tags does this
+ *       in debug builds (to avoid performance issues in non-debug builds), which should be
+ *       the only way to set tags. Hence, at this point we assume the tag bitfield to be valid.
+ */
+int RNA_property_tags(PropertyRNA *prop)
+{
+	return rna_ensure_property(prop)->tags;
+}
+
 bool RNA_property_builtin(PropertyRNA *prop)
 {
 	return (rna_ensure_property(prop)->flag_internal & PROP_INTERN_BUILTIN) != 0;
@@ -1613,6 +1629,18 @@ int RNA_enum_from_value(const EnumPropertyItem *item, const int value)
 	return -1;
 }
 
+unsigned int RNA_enum_items_count(const EnumPropertyItem *item)
+{
+	unsigned int i = 0;
+
+	while (item->identifier) {
+		item++;
+		i++;
+	}
+
+	return i;
+}
+
 bool RNA_property_enum_identifier(bContext *C, PointerRNA *ptr, PropertyRNA *prop, const int value,
                                   const char **identifier)
 {