Override open_group, close_group methods in PathEffectRenderer

Author: chaoyihu

lib/matplotlib/patheffects.py

@@ -152,6 +152,12 @@ def __getattribute__(self, name):
         else:
             return object.__getattribute__(self, name)
 
+    def open_group(self, s, gid=None):
+        return self._renderer.open_group(s, gid)
+
+    def close_group(self, s):
+        return self._renderer.close_group(s)
+
 
 class Normal(AbstractPathEffect):
     """

lib/matplotlib/tests/test_patheffects.py

@@ -5,6 +5,8 @@
 import matplotlib.patheffects as path_effects
 from matplotlib.path import Path
 import matplotlib.patches as patches
+from matplotlib.backend_bases import RendererBase
+from matplotlib.patheffects import PathEffectRenderer
 
 
 @image_comparison(['patheffect1'], remove_text=True)
@@ -192,3 +194,20 @@ def test_patheffects_spaces_and_newlines():
                     bbox={'color': 'thistle'})
     text1.set_path_effects([path_effects.Normal()])
     text2.set_path_effects([path_effects.Normal()])
+
+
+def test_patheffects_overridden_methods_open_close_group():
+    class CustomRenderer(RendererBase):
+        def __init__(self):
+            super().__init__()
+
+        def open_group(self, s, gid=None):
+            return "open_group overridden"
+
+        def close_group(self, s):
+            return "close_group overridden"
+
+    renderer = PathEffectRenderer([path_effects.Normal()], CustomRenderer())
+
+    assert renderer.open_group('s') == "open_group overridden"
+    assert renderer.close_group('s') == "close_group overridden"