Aug 26, 2022 · Aug 25, 2022
diff --git a/doc/api/next_api_changes/removals/22081-AL.rst b/doc/api/next_api_changes/removals/22081-AL.rst
 colorbar defaults to stealing space from the mappable's axes rather than the current axes
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

 Pass ``ax=plt.gca()`` to restore the previous behavior.
 If the mappable does not have an Axes, then an error will be raised.

 Pass the *cax* or *ax* argument to be explicit about where the colorbar will be
 placed. Passing ``ax=plt.gca()`` will restore the previous behavior.

 Removal of deprecated ``colorbar`` APIs
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
diff --git a/lib/matplotlib/figure.py b/lib/matplotlib/figure.py
        """

        if ax is None:
            ax = getattr(mappable, "axes",self.gca())
            ax = getattr(mappable, "axes",None)

        if (self.get_layout_engine() is not None and
                not self.get_layout_engine().colorbar_gridspec):
            use_gridspec = False
        # Store the value of gca so that we can set it back later on.
        if cax is None:
            if ax is None:
                raise ValueError(
                    'Unable to determine Axes to steal space for Colorbar. '
                    'Either provide the *cax* argument to use as the Axes for '
                    'the Colorbar, provide the *ax* argument to steal space '
                    'from it, or add *mappable* to an Axes.')
            current_ax = self.gca()
            userax = False
            if (use_gridspec and isinstance(ax, SubplotBase)):
diff --git a/lib/matplotlib/tests/test_colorbar.py b/lib/matplotlib/tests/test_colorbar.py
    Colorbar(ax, cmap=plt.cm.bone)


 def test_parentless_mappable():
    pc = mpl.collections.PatchCollection([], cmap=plt.get_cmap('viridis'))
    pc.set_array([])

    with pytest.raises(ValueError, match='Unable to determine Axes to steal'):
        plt.colorbar(pc)


 @image_comparison(['colorbar_closed_patch.png'], remove_text=True)
 def test_colorbar_closed_patch():
    # Remove this line when this test image is regenerated.
 def test_mappable_no_alpha():
    fig, ax = plt.subplots()
    sm = cm.ScalarMappable(norm=mcolors.Normalize(), cmap='viridis')
    fig.colorbar(sm)
    fig.colorbar(sm, ax=ax)
    sm.set_cmap('plasma')
    plt.draw()
Original file line number	Diff line number	Diff line change
		@@ -1,7 +1,10 @@
		colorbar defaults to stealing space from the mappable's axes rather than the current axes
		~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

		Pass ``ax=plt.gca()`` to restore the previous behavior.
		If the mappable does not have an Axes, then an error will be raised.

		Pass the cax or ax argument to be explicit about where the colorbar will be
		placed. Passing ``ax=plt.gca()`` will restore the previous behavior.

		Removal of deprecated ``colorbar`` APIs
		~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -1245,13 +1245,19 @@ def colorbar(
		"""

		if ax is None:
		ax = getattr(mappable, "axes",self.gca())
		ax = getattr(mappable, "axes",None)

		if (self.get_layout_engine() is not None and
		not self.get_layout_engine().colorbar_gridspec):
		use_gridspec = False
		# Store the value of gca so that we can set it back later on.
		if cax is None:
		if ax is None:
		raise ValueError(
		'Unable to determine Axes to steal space for Colorbar. '
		'Either provide the cax argument to use as the Axes for '
		'the Colorbar, provide the ax argument to steal space '
		'from it, or add mappable to an Axes.')
		current_ax = self.gca()
		userax = False
		if (use_gridspec and isinstance(ax, SubplotBase)):
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -315,6 +315,14 @@ def test_colorbarbase():
		Colorbar(ax, cmap=plt.cm.bone)


		def test_parentless_mappable():
		pc = mpl.collections.PatchCollection([], cmap=plt.get_cmap('viridis'))
		pc.set_array([])

		with pytest.raises(ValueError, match='Unable to determine Axes to steal'):
		plt.colorbar(pc)


		@image_comparison(['colorbar_closed_patch.png'], remove_text=True)
		def test_colorbar_closed_patch():
		# Remove this line when this test image is regenerated.
Expand DownExpand Up		@@ -675,7 +683,7 @@ def test_colorbar_inverted_ticks():
		def test_mappable_no_alpha():
		fig, ax = plt.subplots()
		sm = cm.ScalarMappable(norm=mcolors.Normalize(), cmap='viridis')
		fig.colorbar(sm)
		fig.colorbar(sm, ax=ax)
		sm.set_cmap('plasma')
		plt.draw()

Expand Down