Merge pull request #16576 from anntzer/axesclassfactory-default

jklymak · web-flow · commit 476445234b7a · 2020-03-11T09:38:45.000-07:00
Deprecate arg-less calls to subplot_class_factory (and similar factories)
diff --git a/doc/api/next_api_changes/deprecations.rst b/doc/api/next_api_changes/deprecations.rst
@@ -317,3 +317,12 @@ Axis and Locator ``pan`` and ``zoom``
 The unused ``pan`` and ``zoom`` methods of `~.axis.Axis` and `~.ticker.Locator`
 are deprecated.  Panning and zooming are now implemented using the
 ``start_pan``, ``drag_pan``, and ``end_pan`` methods of `~.axes.Axes`.
+
+Passing None to various Axes subclass factories
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Support for passing ``None`` as base class to `.axes.subplot_class_factory`,
+``axes_grid1.parasite_axes.host_axes_class_factory``,
+``axes_grid1.parasite_axes.host_subplot_class_factory``,
+``axes_grid1.parasite_axes.parasite_axes_class_factory``, and
+``axes_grid1.parasite_axes.parasite_axes_auxtrans_class_factory`` is deprecated.
+Explicitly pass the correct base ``Axes`` class instead.
diff --git a/lib/matplotlib/axes/_subplots.py b/lib/matplotlib/axes/_subplots.py
@@ -186,6 +186,9 @@ def subplot_class_factory(axes_class=None):
     not have to be created for every type of Axes.
     """
     if axes_class is None:
+        cbook.warn_deprecated(
+            "3.3", message="Support for passing None to subplot_class_factory "
+            "is deprecated; explicitly pass the default Axes class instead.")
         axes_class = Axes
     try:
         # Avoid creating two different instances of GeoAxesSubplot...
@@ -199,8 +202,7 @@ def subplot_class_factory(axes_class=None):
                     {'_axes_class': axes_class})
 
 
-# This is provided for backward compatibility
-Subplot = subplot_class_factory()
+Subplot = subplot_class_factory(Axes)  # Provided for backward compatibility.
 
 
 def _picklable_subplot_class_constructor(axes_class):
diff --git a/lib/mpl_toolkits/axes_grid1/parasite_axes.py b/lib/mpl_toolkits/axes_grid1/parasite_axes.py
@@ -52,13 +52,17 @@ def pick(self, mouseevent):
 @functools.lru_cache(None)
 def parasite_axes_class_factory(axes_class=None):
     if axes_class is None:
+        cbook.warn_deprecated(
+            "3.3", message="Support for passing None to "
+            "parasite_axes_class_factory is deprecated; explicitly pass the "
+            "default Axes class instead.")
         axes_class = Axes
 
     return type("%sParasite" % axes_class.__name__,
                 (ParasiteAxesBase, axes_class), {})
 
 
-ParasiteAxes = parasite_axes_class_factory()
+ParasiteAxes = parasite_axes_class_factory(Axes)
 
 
 class ParasiteAxesAuxTransBase:
@@ -175,6 +179,10 @@ def apply_aspect(self, position=None):
 @functools.lru_cache(None)
 def parasite_axes_auxtrans_class_factory(axes_class=None):
     if axes_class is None:
+        cbook.warn_deprecated(
+            "3.3", message="Support for passing None to "
+            "parasite_axes_auxtrans_class_factory is deprecated; explicitly "
+            "pass the default ParasiteAxes class instead.")
         parasite_axes_class = ParasiteAxes
     elif not issubclass(axes_class, ParasiteAxesBase):
         parasite_axes_class = parasite_axes_class_factory(axes_class)
@@ -185,16 +193,15 @@ def parasite_axes_auxtrans_class_factory(axes_class=None):
                 {'name': 'parasite_axes'})
 
 
-ParasiteAxesAuxTrans = parasite_axes_auxtrans_class_factory(
-    axes_class=ParasiteAxes)
+ParasiteAxesAuxTrans = parasite_axes_auxtrans_class_factory(ParasiteAxes)
 
 
 class HostAxesBase:
     def __init__(self, *args, **kwargs):
         self.parasites = []
         super().__init__(*args, **kwargs)
 
-    def get_aux_axes(self, tr, viewlim_mode="equal", axes_class=None):
+    def get_aux_axes(self, tr, viewlim_mode="equal", axes_class=ParasiteAxes):
         parasite_axes_class = parasite_axes_auxtrans_class_factory(axes_class)
         ax2 = parasite_axes_class(self, tr, viewlim_mode)
         # note that ax2.transData == tr + ax1.transData
@@ -354,6 +361,9 @@ def get_tightbbox(self, renderer, call_axes_locator=True,
 @functools.lru_cache(None)
 def host_axes_class_factory(axes_class=None):
     if axes_class is None:
+        cbook.warn_deprecated(
+            "3.3", message="Support for passing None to host_axes_class is "
+            "deprecated; explicitly pass the default Axes class instead.")
         axes_class = Axes
 
     def _get_base_axes(self):
@@ -365,16 +375,16 @@ def _get_base_axes(self):
 
 
 def host_subplot_class_factory(axes_class):
-    host_axes_class = host_axes_class_factory(axes_class=axes_class)
+    host_axes_class = host_axes_class_factory(axes_class)
     subplot_host_class = subplot_class_factory(host_axes_class)
     return subplot_host_class
 
 
-HostAxes = host_axes_class_factory(axes_class=Axes)
+HostAxes = host_axes_class_factory(Axes)
 SubplotHost = subplot_class_factory(HostAxes)
 
 
-def host_axes(*args, axes_class=None, figure=None, **kwargs):
+def host_axes(*args, axes_class=Axes, figure=None, **kwargs):
     """
     Create axes that can act as a hosts to parasitic axes.
 
@@ -397,7 +407,7 @@ def host_axes(*args, axes_class=None, figure=None, **kwargs):
     return ax
 
 
-def host_subplot(*args, axes_class=None, figure=None, **kwargs):
+def host_subplot(*args, axes_class=Axes, figure=None, **kwargs):
     """
     Create a subplot that can act as a host to parasitic axes.
 
