Changes to SubFigures so it behave like a regular artist:

Cyril Gadal · Cyril Gadal · commit 808a9e7fba74 · 2023-09-22T11:51:23.000+02:00
- changing self._get_draw_artists() so subfigs are now part of the
  artists list.
- changing draw() methods so subfigs are drawn like regular artists
diff --git a/lib/matplotlib/figure.py b/lib/matplotlib/figure.py
@@ -120,6 +120,7 @@ class FigureBase(Artist):
     Base class for `.Figure` and `.SubFigure` containing the methods that add
     artists to the figure or subfigure, create Axes, etc.
     """
+
     def __init__(self, **kwargs):
         super().__init__()
         # remove the non-figure artist _axes property
@@ -152,12 +153,12 @@ def __init__(self, **kwargs):
     def _get_draw_artists(self, renderer):
         """Also runs apply_aspect"""
         artists = self.get_children()
-        for sfig in self.subfigs:
-            artists.remove(sfig)
-            childa = sfig.get_children()
-            for child in childa:
-                if child in artists:
-                    artists.remove(child)
+        # for sfig in self.subfigs:
+        #     artists.remove(sfig)
+        #     childa = sfig.get_children()
+        #     for child in childa:
+        #         if child in artists:
+        #             artists.remove(child)
 
         artists.remove(self.patch)
         artists = sorted(
@@ -2294,8 +2295,7 @@ def draw(self, renderer):
             self.patch.draw(renderer)
             mimage._draw_list_compositing_images(
                 renderer, self, artists, self.figure.suppressComposite)
-            for sfig in self.subfigs:
-                sfig.draw(renderer)
+
             renderer.close_group('subfigure')
 
         finally:
@@ -2782,8 +2782,8 @@ def set_constrained_layout(self, constrained):
         self.stale = True
 
     @_api.deprecated(
-         "3.6", alternative="figure.get_layout_engine().set()",
-         pending=True)
+        "3.6", alternative="figure.get_layout_engine().set()",
+        pending=True)
     def set_constrained_layout_pads(self, **kwargs):
         """
         Set padding for ``constrained_layout``.
@@ -3101,9 +3101,6 @@ def draw(self, renderer):
                 mimage._draw_list_compositing_images(
                     renderer, self, artists, self.suppressComposite)
 
-                for sfig in self.subfigs:
-                    sfig.draw(renderer)
-
                 renderer.close_group('figure')
             finally:
                 self.stale = False
