Accept strings for {Cap,Join}Style in MarkerStyle

When these Enum classes were added in matplotlib#18544, they were supposed to be
for documentation only. To that end, matplotlib#22055 was a followup that ensured
that only the strings were exposed from the getter side.

However, when user-supplied cap/join style were added in matplotlib#20914, they
were only for the Enum type instead of the string, so correctly allow
strings here as well.

Also, specifically type hint the return values as literals, as was done
in matplotlib#25719.

Author: QuLogic

lib/matplotlib/markers.py

@@ -241,16 +241,16 @@ def __init__(self, marker,
             Transform that will be combined with the native transform of the
             marker.
 
-        capstyle : CapStyle, default: None
+        capstyle : `.CapStyle` or %(CapStyle)s, default: None
             Cap style that will override the default cap style of the marker.
 
-        joinstyle : JoinStyle, default: None
+        joinstyle : `.JoinStyle` or %(JoinStyle)s, default: None
             Join style that will override the default join style of the marker.
         """
         self._marker_function = None
         self._user_transform = transform
-        self._user_capstyle = capstyle
-        self._user_joinstyle = joinstyle
+        self._user_capstyle = CapStyle(capstyle) if capstyle is not None else None
+        self._user_joinstyle = JoinStyle(joinstyle) if joinstyle is not None else None
         self._set_fillstyle(fillstyle)
         self._set_marker(marker)
 

lib/matplotlib/markers.pyi

@@ -1,9 +1,10 @@
-from ._enums import CapStyle, JoinStyle
+from typing import Literal
+
 from .path import Path
 from .transforms import Affine2D, Transform
 
 from numpy.typing import ArrayLike
-from .typing import FillStyleType
+from .typing import CapStyleType, FillStyleType, JoinStyleType
 
 TICKLEFT: int
 TICKRIGHT: int
@@ -28,16 +29,14 @@ class MarkerStyle:
         marker: str | ArrayLike | Path | MarkerStyle | None,
         fillstyle: FillStyleType | None = ...,
         transform: Transform | None = ...,
-        capstyle: CapStyle | None = ...,
-        joinstyle: JoinStyle | None = ...,
+        capstyle: CapStyleType | None = ...,
+        joinstyle: JoinStyleType | None = ...,
     ) -> None: ...
     def __bool__(self) -> bool: ...
     def is_filled(self) -> bool: ...
-    def get_fillstyle(
-        self,
-    ) -> FillStyleType: ...
-    def get_joinstyle(self) -> JoinStyle: ...
-    def get_capstyle(self) -> CapStyle: ...
+    def get_fillstyle(self) -> FillStyleType: ...
+    def get_joinstyle(self) -> Literal["miter", "round", "bevel"]: ...
+    def get_capstyle(self) -> Literal["butt", "projecting", "round"]: ...
     def get_marker(self) -> str | ArrayLike | Path | MarkerStyle | None: ...
     def get_path(self) -> Path: ...
     def get_transform(self) -> Transform: ...

lib/matplotlib/tests/test_marker.py

@@ -207,18 +207,16 @@ def test_marker_init_transforms():
 
 def test_marker_init_joinstyle():
     marker = markers.MarkerStyle("*")
-    jstl = markers.JoinStyle.round
-    styled_marker = markers.MarkerStyle("*", joinstyle=jstl)
-    assert styled_marker.get_joinstyle() == jstl
-    assert marker.get_joinstyle() != jstl
+    styled_marker = markers.MarkerStyle("*", joinstyle="round")
+    assert styled_marker.get_joinstyle() == "round"
+    assert marker.get_joinstyle() != "round"
 
 
 def test_marker_init_captyle():
     marker = markers.MarkerStyle("*")
-    capstl = markers.CapStyle.round
-    styled_marker = markers.MarkerStyle("*", capstyle=capstl)
-    assert styled_marker.get_capstyle() == capstl
-    assert marker.get_capstyle() != capstl
+    styled_marker = markers.MarkerStyle("*", capstyle="round")
+    assert styled_marker.get_capstyle() == "round"
+    assert marker.get_capstyle() != "round"
 
 
 @pytest.mark.parametrize("marker,transform,expected", [