Proof of concept for adding kwdoc content to properties using a decorator

timhoffm · timhoffm · commit a7a0a677956d · 2023-12-16T10:12:44.000+01:00
diff --git a/lib/matplotlib/_docstring.py b/lib/matplotlib/_docstring.py
@@ -3,6 +3,31 @@
 from . import _api
 
 
+def kwarg_doc(text):
+    """
+    Decorator for defining the documentation used when artist properties are
+    passed through as keyword arguments.
+
+    See e.g. the `**kwargs` section in `.Axes.text`.
+
+    The given text is stored in a privat variable ``_kwarg_doc`` on the method.
+    It is used for generating the kwdoc list for artists, which we
+    auto-generate through docstring interpolation, e.g. via
+    ``%(Line2D:kwdoc)s``.
+
+    The text should contain the supported types as well as the default value
+    if applicable, e.g.:
+
+        @_docstring.kwarg_doc("bool, default: :rc:`text.usetex`")
+        def set_usetex(self, usetex):
+
+    """
+    def decorator(func):
+        func._kwarg_doc = text
+        return func
+    return decorator
+
+
 class Substitution:
     """
     A decorator that performs %-substitution on an object's docstring.
diff --git a/lib/matplotlib/_docstring.pyi b/lib/matplotlib/_docstring.pyi
@@ -4,6 +4,9 @@ from typing import Any, Callable, TypeVar, overload
 _T = TypeVar('_T')
 
 
+def _kwarg_doc(text: str) -> Callable[[_T], _T]: ...
+
+
 class Substitution:
     @overload
     def __init__(self, *args: str): ...
diff --git a/lib/matplotlib/artist.py b/lib/matplotlib/artist.py
@@ -1482,6 +1482,9 @@ def get_valid_values(self, attr):
             raise AttributeError(f'{self.o} has no function {name}')
         func = getattr(self.o, name)
 
+        if hasattr(func, '_kwarg_doc'):
+            return func._kwarg_doc
+
         docstring = inspect.getdoc(func)
         if docstring is None:
             return 'unknown'
diff --git a/lib/matplotlib/text.py b/lib/matplotlib/text.py
@@ -1314,6 +1314,7 @@ def set_fontproperties(self, fp):
         self._fontproperties = FontProperties._from_any(fp).copy()
         self.stale = True
 
+    @_docstring.kwarg_doc("bool, default: :rc:`text.usetex`")
     def set_usetex(self, usetex):
         """
         Parameters
