adds path.effects rcparam support for list of (funcname, {**kwargs})

story645 · anntzer · story645 · commit e0c6e1e16bd9 · 2023-10-16T05:01:17.000-04:00
adds new path.effects validation
created xkcd.mplstyle and shimmed it into plt.xkcd()

Co-authored-by: Antony Lee &lt;anntzer.lee@gmail.com&gt;
diff --git a/lib/matplotlib/__init__.py b/lib/matplotlib/__init__.py
@@ -137,6 +137,7 @@
 from collections import namedtuple
 from collections.abc import MutableMapping
 import contextlib
+import copy
 import functools
 import importlib
 import inspect
@@ -163,7 +164,6 @@
 from matplotlib._api import MatplotlibDeprecationWarning
 from matplotlib.rcsetup import validate_backend, cycler
 
-
 _log = logging.getLogger(__name__)
 
 __bibtex__ = r"""@Article{Hunter:2007,
@@ -764,6 +764,14 @@ def __getitem__(self, key):
                 from matplotlib import pyplot as plt
                 plt.switch_backend(rcsetup._auto_backend_sentinel)
 
+        elif key == "path.effects" and self is globals().get("rcParams"):
+            # defers loading of patheffects to avoid circular imports
+            import matplotlib.patheffects as path_effects
+
+            return [pe if isinstance(pe, path_effects.AbstractPathEffect)
+                    else getattr(path_effects, pe[0])(**pe[1])
+                    for pe in self._get('path.effects')]
+
         return self._get(key)
 
     def _get_backend_or_none(self):
diff --git a/lib/matplotlib/mpl-data/matplotlibrc b/lib/matplotlib/mpl-data/matplotlibrc
@@ -677,7 +677,10 @@
                     #         line (in pixels).
                     #     - *randomness* is the factor by which the length is
                     #         randomly scaled.
-#path.effects:
+#path.effects:      # patheffects functions, args, and, kwargs, e.g 
+                    # {'name': 'withStroke', 'linewidth': 4},
+                    # {'name': 'SimpleLineShadow'}
+
 
 
 ## ***************************************************************************
diff --git a/lib/matplotlib/mpl-data/stylelib/xkcd.mplstyle b/lib/matplotlib/mpl-data/stylelib/xkcd.mplstyle
@@ -0,0 +1,30 @@
+## default xkcd style
+
+# line
+lines.linewidth : 2.0
+
+# font
+font.family : xkcd, xkcd Script, Humor Sans, Comic Neue, Comic Sans MS
+font.size   : 14.0
+
+# axes
+axes.linewidth  : 1.5
+axes.grid       : False
+axes.unicode_minus: False
+axes.edgecolor: black
+
+# ticks
+xtick.major.size : 8
+xtick.major.width: 3
+ytick.major.size : 8
+ytick.major.width: 3
+
+# grids
+grid.linewidth: 0.0
+
+# figure
+figure.facecolor: white
+
+# path
+path.sketch : 1, 100, 2
+path.effects: ('withStroke', {'linewidth': 4, 'foreground': 'w' })
diff --git a/lib/matplotlib/pyplot.py b/lib/matplotlib/pyplot.py
@@ -747,27 +747,8 @@ def xkcd(
     stack = ExitStack()
     stack.callback(dict.update, rcParams, rcParams.copy())  # type: ignore
 
-    from matplotlib import patheffects
-    rcParams.update({
-        'font.family': ['xkcd', 'xkcd Script', 'Humor Sans', 'Comic Neue',
-                        'Comic Sans MS'],
-        'font.size': 14.0,
-        'path.sketch': (scale, length, randomness),
-        'path.effects': [
-            patheffects.withStroke(linewidth=4, foreground="w")],
-        'axes.linewidth': 1.5,
-        'lines.linewidth': 2.0,
-        'figure.facecolor': 'white',
-        'grid.linewidth': 0.0,
-        'axes.grid': False,
-        'axes.unicode_minus': False,
-        'axes.edgecolor': 'black',
-        'xtick.major.size': 8,
-        'xtick.major.width': 3,
-        'ytick.major.size': 8,
-        'ytick.major.width': 3,
-    })
-
+    rcParams.update({**style.library["xkcd"],
+                    'path.sketch': (scale, length, randomness)})
     return stack
 
 
diff --git a/lib/matplotlib/rcsetup.py b/lib/matplotlib/rcsetup.py
@@ -565,6 +565,42 @@ def validate_sketch(s):
         raise ValueError("Expected a (scale, length, randomness) triplet")
 
 
+def validate_path_effects(s):
+    if not s:
+        return []
+
+    if isinstance(s, str) and s.strip().startswith("("):
+        s = ast.literal_eval(s)
+
+    _validate_name = ValidateInStrings("path.effects.function",
+                                        ["Normal",
+                                         "PathPatchEffect",
+                                         "SimpleLineShadow",
+                                         "SimplePatchShadow",
+                                         "Stroke",
+                                         "TickedStroke",
+                                         "withSimplePatchShadow",
+                                         "withStroke",
+                                         "withTickedStroke"])
+
+    def _validate_dict(d):
+        if not isinstance(d, dict):
+            raise ValueError("Expected a dictionary of keyword arguments")
+        return d
+
+    try:
+        # cast to list for the 1 tuple case
+        s = [s] if isinstance(s[0], str) else s
+        return [pe if getattr(pe, '__module__', "") == 'matplotlib.patheffects'
+                else (_validate_name(pe[0].strip()),
+                      {} if len(pe) < 2 else _validate_dict(pe[1]))
+                      for pe in validate_anylist(s)
+                ]
+    except TypeError as e:
+        raise ValueError("Expected a list of patheffects functions"
+                         " or (funcname, {**kwargs}) tuples")
+
+
 def _validate_greaterthan_minushalf(s):
     s = validate_float(s)
     if s > -0.5:
@@ -1290,7 +1326,7 @@ def _convert_validator_spec(key, conv):
     "path.simplify_threshold": _validate_greaterequal0_lessequal1,
     "path.snap":               validate_bool,
     "path.sketch":             validate_sketch,
-    "path.effects":            validate_anylist,
+    "path.effects":            validate_path_effects,
     "agg.path.chunksize":      validate_int,  # 0 to disable chunking
 
     # key-mappings (multi-character mappings should be a list/tuple)
diff --git a/lib/matplotlib/rcsetup.pyi b/lib/matplotlib/rcsetup.pyi
@@ -2,6 +2,7 @@ from cycler import Cycler
 
 from collections.abc import Callable, Iterable
 from typing import Any, Literal, TypeVar
+from matplotlib.patheffects import AbstractPathEffect
 from matplotlib.typing import ColorType, LineStyleType, MarkEveryType
 
 interactive_bk: list[str]
@@ -140,6 +141,8 @@ def _validate_linestyle(s: Any) -> LineStyleType: ...
 def validate_markeverylist(s: Any) -> list[MarkEveryType]: ...
 def validate_bbox(s: Any) -> Literal["tight", "standard"] | None: ...
 def validate_sketch(s: Any) -> None | tuple[float, float, float]: ...
+def validate_path_effects(s: str | list[AbstractPathEffect, Tuple[str,dict]])
+-> list[AbstractPathEffect | [Tuple[str, dict]]]: ...
 def validate_hatch(s: Any) -> str: ...
 def validate_hatchlist(s: Any) -> list[str]: ...
 def validate_dashlist(s: Any) -> list[list[float]]: ...
diff --git a/lib/matplotlib/tests/test_rcparams.py b/lib/matplotlib/tests/test_rcparams.py
@@ -12,6 +12,9 @@
 from matplotlib import _api, _c_internal_utils
 import matplotlib.pyplot as plt
 import matplotlib.colors as mcolors
+import matplotlib.patheffects as path_effects
+from matplotlib.testing.decorators import check_figures_equal
+
 import numpy as np
 from matplotlib.rcsetup import (
     validate_bool,
@@ -27,8 +30,10 @@
     validate_int,
     validate_markevery,
     validate_stringlist,
+    validate_path_effects,
     _validate_linestyle,
-    _listify_validator)
+    _listify_validator,
+    )
 
 
 def test_rcparams(tmpdir):
@@ -628,3 +633,62 @@ def test_rcparams_legend_loc_from_file(tmpdir, value):
 
     with mpl.rc_context(fname=rc_path):
         assert mpl.rcParams["legend.loc"] == value
+
+ped = [('Normal', {}),
+       ('Stroke', {'offset': (1, 2)}),
+       ('withStroke', {'linewidth': 4, 'foreground': 'w'})]
+
+pel = [path_effects.Normal(),
+       path_effects.Stroke((1, 2)),
+       path_effects.withStroke(linewidth=4, foreground='w')]
+
+
+@pytest.mark.parametrize("value", [pel, ped], ids=["func", "dict"])
+def test_path_effects(value):
+    assert validate_path_effects(value) == value
+    for v in value:
+        assert validate_path_effects(value) == value
+
+
+def test_path_effects_string():
+    """test list of dicts properly parsed"""
+    pstr = "('Normal', ), "
+    pstr += "('Stroke', {'offset': (1, 2)}),"
+    pstr += "('withStroke', {'linewidth': 4, 'foreground': 'w'})"
+    assert validate_path_effects(pstr) == ped
+
+
+@pytest.mark.parametrize("fdict, flist",
+                         [([ped[0]], [pel[0]]),
+                          ([ped[1]], [pel[1]]),
+                          ([ped[2]], [ped[2]]),
+                          (ped, pel)],
+                         ids=['function', 'args', 'kwargs', 'all'])
+@check_figures_equal()
+def test_path_effects_picture(fig_test, fig_ref, fdict, flist):
+    with mpl.rc_context({'path.effects': fdict}):
+        fig_test.subplots().plot([1, 2, 3])
+
+    with mpl.rc_context({'path.effects': flist}):
+        fig_ref.subplots().plot([1, 2, 3])
+
+
+@pytest.mark.parametrize("s, msg", [
+ ([1, 2, 3], "Expected a list of patheffects .*"),
+ (("Happy", ), r".* \'Happy\' is not a valid value for path\.effects\.function.*"),
+ (("Normal", [1, 2, 3]), r"Expected a dictionary .*"),])
+def test_path_effect_errors(s, msg):
+    with pytest.raises(ValueError, match=msg):
+        mpl.rcParams['path.effects'] = s
+
+
+def test_path_effects_from_file(tmpdir):
+    # rcParams['legend.loc'] should be settable from matplotlibrc.
+    # if any of these are not allowed, an exception will be raised.
+    # test for gh issue #22338
+    rc_path = tmpdir.join("matplotlibrc")
+    rc_path.write("path.effects: ('Normal', {}), ('withStroke', {'linewidth': 2})")
+
+    with mpl.rc_context(fname=rc_path):
+        assert isinstance(mpl.rcParams["path.effects"][0], path_effects.Normal)
+        assert isinstance(mpl.rcParams["path.effects"][1], path_effects.withStroke)
diff --git a/lib/matplotlib/tests/test_style.py b/lib/matplotlib/tests/test_style.py
@@ -8,6 +8,7 @@
 
 import matplotlib as mpl
 from matplotlib import pyplot as plt, style
+from matplotlib.testing.decorators import check_figures_equal
 from matplotlib.style.core import USER_LIBRARY_PATHS, STYLE_EXTENSION
 
 
@@ -177,6 +178,18 @@ def test_xkcd_cm():
     assert mpl.rcParams["path.sketch"] is None
 
 
+@check_figures_equal()
+def test_xkcd_style(fig_test, fig_ref):
+
+    with style.context('xkcd'):
+        fig_test.subplots().plot([1, 2, 3])
+        fig_test.text(.5, .5, "Hello World!")
+
+    with plt.xkcd():
+        fig_ref.subplots().plot([1, 2, 3])
+        fig_ref.text(.5, .5, "Hello World!")
+
+
 def test_up_to_date_blacklist():
     assert mpl.style.core.STYLE_BLACKLIST <= {*mpl.rcsetup._validators}
 
