PyDoc: replace in-lined enum references with links where possible

Avoid in-lining large enums such as icons and event types, linking
to them instead.

This mitigates T76453, where long enums took a lot of space in the docs,
this was a problem with `UILayout` where each icon argument would list
all icons. [0] worked around the issue using CSS to scroll the list.
However this has the draw-back where some items are clipped in a way
that's not obvious, see: T87008.

The reason this isn't a complete solution is that Python defined enums
aren't written into their own pages which can be linked to, although
currently there are no large Python enums included in the API docs.
All in-lined enums are now under 20 items.

[0]: 1e8f2665916c049748a3985a2fce736701925095

1 files changed, 65 insertions, 7 deletions

diff --git a/doc/python_api/sphinx_doc_gen.py b/doc/python_api/sphinx_doc_gen.py
index ebaea669679..0d514e0694d 100644
--- a/doc/python_api/sphinx_doc_gen.py
+++ b/doc/python_api/sphinx_doc_gen.py
@@ -89,6 +89,16 @@ if USE_SHARED_RNA_ENUM_ITEMS_STATIC:
         del rna_enum_dict[key]
     del key, rna_enum_items_static
 
+    # Build enum `{pointer: identifier}` map, so any enum property pointer can
+    # lookup an identifier using `InfoPropertyRNA.enum_pointer` as the key.
+    rna_enum_pointer_to_id_map = {
+        enum_prop.as_pointer(): key
+        for key, enum_items in rna_enum_dict.items()
+        # It's possible the first item is a heading (which has no identifier).
+        # skip these as the `EnumProperty.enum_items` does not expose them.
+        if (enum_prop := next(iter(enum_prop for enum_prop in enum_items if enum_prop.identifier), None))
+    }
+
 
 def handle_args():
     """
@@ -1231,15 +1241,23 @@ def pycontext2sphinx(basepath):
             # No need to check if there are duplicates yet as it's known there wont be.
             unique.add(prop.identifier)
 
+            enum_descr_override = None
+            if USE_SHARED_RNA_ENUM_ITEMS_STATIC:
+                enum_descr_override = pyrna_enum2sphinx_shared_link(prop)
+
             type_descr = prop.get_type_description(
-                class_fmt=":class:`bpy.types.%s`", collection_id=_BPY_PROP_COLLECTION_ID)
+                class_fmt=":class:`bpy.types.%s`",
+                collection_id=_BPY_PROP_COLLECTION_ID,
+                enum_descr_override=enum_descr_override,
+            )
             fw(".. data:: %s\n\n" % prop.identifier)
             if prop.description:
                 fw("   %s\n\n" % prop.description)
 
             # Special exception, can't use generic code here for enums.
             if prop.type == "enum":
-                enum_text = pyrna_enum2sphinx(prop)
+                # If the link has been written, no need to inline the enum items.
+                enum_text = "" if enum_descr_override else pyrna_enum2sphinx(prop)
                 if enum_text:
                     write_indented_lines("   ", fw, enum_text)
                     fw("\n")
@@ -1301,6 +1319,11 @@ def pyrna_enum2sphinx(prop, use_empty_descriptions=False):
     Write a bullet point list of enum + descriptions.
     """
 
+    # Write a link to the enum if this is part of `rna_enum_pointer_map`.
+    if USE_SHARED_RNA_ENUM_ITEMS_STATIC:
+        if (result := pyrna_enum2sphinx_shared_link(prop)) is not None:
+            return result
+
     if use_empty_descriptions:
         ok = True
     else:
@@ -1379,10 +1402,15 @@ def pyrna2sphinx(basepath):
 
         kwargs["collection_id"] = _BPY_PROP_COLLECTION_ID
 
-        type_descr = prop.get_type_description(**kwargs)
+        enum_descr_override = None
+        if USE_SHARED_RNA_ENUM_ITEMS_STATIC:
+            enum_descr_override = pyrna_enum2sphinx_shared_link(prop)
+            kwargs["enum_descr_override"] = enum_descr_override
 
-        enum_text = pyrna_enum2sphinx(prop)
+        type_descr = prop.get_type_description(**kwargs)
 
+        # If the link has been written, no need to inline the enum items.
+        enum_text = "" if enum_descr_override else pyrna_enum2sphinx(prop)
         if prop.name or prop.description or enum_text:
             fw(ident + ":%s%s:\n\n" % (id_name, identifier))
 
@@ -1483,7 +1511,15 @@ def pyrna2sphinx(basepath):
             if identifier in struct_blacklist:
                 continue
 
-            type_descr = prop.get_type_description(class_fmt=":class:`%s`", collection_id=_BPY_PROP_COLLECTION_ID)
+            enum_descr_override = None
+            if USE_SHARED_RNA_ENUM_ITEMS_STATIC:
+                enum_descr_override = pyrna_enum2sphinx_shared_link(prop)
+
+            type_descr = prop.get_type_description(
+                class_fmt=":class:`%s`",
+                collection_id=_BPY_PROP_COLLECTION_ID,
+                enum_descr_override=enum_descr_override,
+            )
             # Read-only properties use "data" directive, variables properties use "attribute" directive.
             if "readonly" in type_descr:
                 fw("   .. data:: %s\n" % identifier)
@@ -1500,7 +1536,8 @@ def pyrna2sphinx(basepath):
 
             # Special exception, can't use generic code here for enums.
             if prop.type == "enum":
-                enum_text = pyrna_enum2sphinx(prop)
+                # If the link has been written, no need to inline the enum items.
+                enum_text = "" if enum_descr_override else pyrna_enum2sphinx(prop)
                 if enum_text:
                     write_indented_lines("      ", fw, enum_text)
                     fw("\n")
@@ -1539,8 +1576,16 @@ def pyrna2sphinx(basepath):
                 for prop in func.return_values:
                     # TODO: pyrna_enum2sphinx for multiple return values... actually don't
                     # think we even use this but still!
+
+                    enum_descr_override = None
+                    if USE_SHARED_RNA_ENUM_ITEMS_STATIC:
+                        enum_descr_override = pyrna_enum2sphinx_shared_link(prop)
+
                     type_descr = prop.get_type_description(
-                        as_ret=True, class_fmt=":class:`%s`", collection_id=_BPY_PROP_COLLECTION_ID)
+                        as_ret=True, class_fmt=":class:`%s`",
+                        collection_id=_BPY_PROP_COLLECTION_ID,
+                        enum_descr_override=enum_descr_override,
+                    )
                     descr = prop.description
                     if not descr:
                         descr = prop.name
@@ -2067,6 +2112,19 @@ def write_rst_data(basepath):
         EXAMPLE_SET_USED.add("bpy.data")
 
 
+def pyrna_enum2sphinx_shared_link(prop):
+    """
+    Return a reference to the enum used by ``prop`` or None when not found.
+    """
+    if (
+            (prop.type == "enum") and
+            (pointer := prop.enum_pointer) and
+            (identifier := rna_enum_pointer_to_id_map.get(pointer))
+    ):
+        return ":ref:`%s`" % identifier
+    return None
+
+
 def write_rst_enum_items(basepath, key, key_no_prefix, enum_items):
     """
     Write a single page for a static enum in RST.