Dec 4, 2022 · Dec 4, 2022
diff --git a/lib/matplotlib/artist.py b/lib/matplotlib/artist.py

 _log = logging.getLogger(__name__)

 # a tombstone sentinel to ensure we never reset the axes or figure on an Artist
 _tombstone = object()


 def _prevent_rasterization(draw):
    # We assume that by default artists are not allowed to rasterize (unless
        self._stale = True
        self.stale_callback = None
        self._axes = None
        self.figure = None
        self._figure = None

        self._transform = None
        self._transformSet = False
    @property
    def axes(self):
        """The `~.axes.Axes` instance the artist resides in, or *None*."""
        return self._axes
        return self._axes if self._axes is not _tombstone else None

    @axes.setter
    def axes(self, new_axes):
        if (new_axes is not None and self._axes is not None
                and new_axes != self._axes):
            raise ValueError("Can not reset the Axes. You are probably trying to reuse "
                             "an artist in more than one Axes which is not supported")
            if self._axes is _tombstone:
                extra = (
                    f"The artist {self!r} has had its Axes reset to None " +
                    "but was previously included in one."
                )
            else:
                extra = (
                    f"The artist {self!r} is currently in {self._axes!r} " +
                    f"in the figure {self._axes.figure!r}."
                )
            raise ValueError("Can not reset the Axes.  You are probably " +
                             "trying to re-use an artist in more than one " +
                             "Axes which is not supported.  " +
                             extra
                             )
        if self._axes is not None and new_axes is None:
            new_axes = _tombstone
        self._axes = new_axes
        if new_axes is not None and new_axes is not self:
            self.stale_callback = _stale_axes_callback

    @property
    def figure(self):
        """The `~.figure.Figure` instance the artist resides in, or *None*."""
        return self._figure if self._figure is not _tombstone else None

    @figure.setter
    def figure(self, new_figure):
        if (new_figure is not None and self._figure is not None
                and new_figure != self._figure and new_figure is not True):
            if self._figure is _tombstone:
                extra = (
                    f"The artist {self!r} has had its Figure reset to None " +
                    "but was previously included in one."
                )
            else:
                extra = (
                    f"The artist {self!r} is currently in {self._figure!r}."
                )
            raise ValueError("Can not reset the figure.  You are probably " +
                             "trying to re-use an artist in more than one " +
                             "Figure which is not supported.  " +
                             extra
                             )
        if self._figure is not None and new_figure is None:
            new_figure = _tombstone
        self._figure = new_figure

    @property
    def stale(self):
        """
        # if this is a no-op just return
        if self.figure is fig:
            return
        # if we currently have a figure (the case of both `self.figure`
        # and *fig* being none is taken care of above) we then user is
        # trying to change the figure an artist is associated with which
        # is not allowed for the same reason as adding the same instance
        # to more than one Axes
        if self.figure is not None:
            raise RuntimeError("Can not put single artist in "
                               "more than one figure")
        self.figure = fig
        if self.figure and self.figure is not self:
            self.pchanged()
diff --git a/lib/matplotlib/figure.py b/lib/matplotlib/figure.py
        # axis._get_tick_boxes_siblings
        self._align_label_groups = {"x": cbook.Grouper(), "y": cbook.Grouper()}

        self._figure = self
        self._localaxes = []  # track all Axes
        self.artists = []
        self.lines = []

        self._subplotspec = subplotspec
        self._parent = parent
        self.figure = parent.figure
        self._figure = parent.figure

        # subfigures use the parent axstack
        self._axstack = parent._axstack
diff --git a/lib/matplotlib/tests/test_artist.py b/lib/matplotlib/tests/test_artist.py

    assert 'aardvark' == art.draw(renderer, 'aardvark')
    assert 'aardvark' == art.draw(renderer, extra='aardvark')


 def test_no_reset():
    fig, (ax1, ax2) = plt.subplots(2)
    fig2 = plt.figure()
    ln, = ax1.plot(range(5))
    with pytest.raises(
            ValueError, match=f"The artist {ln!r} is currently in {ax1!r}"
    ):
        ax2.add_line(ln)
    with pytest.raises(
            ValueError, match=f"The artist {ln!r} is currently in {ax1!r}"
    ):
        ln.axes = ax2
    with pytest.raises(
            ValueError, match=f"The artist {ln!r} is currently in {fig!r}"
    ):
        ln.figure = fig2

    ln.remove()
    assert ln.figure is None
    assert ln.axes is None
    with pytest.raises(
            ValueError, match=f"The artist {ln!r} has had its Figure reset "
    ):
        ax2.add_line(ln)
    with pytest.raises(
            ValueError, match=f"The artist {ln!r} has had its Axes reset "
    ):
        ln.axes = ax2

    assert ln.axes is None
    assert ln.figure is None
diff --git a/lib/matplotlib/tests/test_offsetbox.py b/lib/matplotlib/tests/test_offsetbox.py
             'center': 10,
             }
    fig, ax = plt.subplots()
    da = DrawingArea(100, 100)

    for code in codes:
        da = DrawingArea(100, 100)
        anchored_box = AnchoredOffsetbox(loc=code, child=da)
        ax.add_artist(anchored_box)
    fig.canvas.draw()
Original file line number	Diff line number	Diff line change
Expand Up		@@ -20,6 +20,9 @@

		_log = logging.getLogger(__name__)

		# a tombstone sentinel to ensure we never reset the axes or figure on an Artist
		_tombstone = object()


		def _prevent_rasterization(draw):
		# We assume that by default artists are not allowed to rasterize (unless
Expand DownExpand Up		@@ -181,7 +184,7 @@ def __init__(self):
		self._stale = True
		self.stale_callback = None
		self._axes = None
		self.figure = None
		self._figure = None

		self._transform = None
		self._transformSet = False
Expand DownExpand Up		@@ -293,18 +296,60 @@ def convert_yunits(self, y):
		@property
		def axes(self):
		"""The `~.axes.Axes` instance the artist resides in, or None."""
		return self._axes
		return self._axes if self._axes is not _tombstone else None

		@axes.setter
		def axes(self, new_axes):
		if (new_axes is not None and self._axes is not None
		and new_axes != self._axes):
		raise ValueError("Can not reset the Axes. You are probably trying to reuse "
		"an artist in more than one Axes which is not supported")
		if self._axes is _tombstone:
		extra = (
		f"The artist {self!r} has had its Axes reset to None " +
		"but was previously included in one."
		)
		else:
		extra = (
		f"The artist {self!r} is currently in {self._axes!r} " +
		f"in the figure {self._axes.figure!r}."
		)
		raise ValueError("Can not reset the Axes. You are probably " +
		"trying to re-use an artist in more than one " +
		"Axes which is not supported. " +
		extra
		)
		if self._axes is not None and new_axes is None:
		new_axes = _tombstone
		self._axes = new_axes
		if new_axes is not None and new_axes is not self:
		self.stale_callback = _stale_axes_callback

		@property
		def figure(self):
		"""The `~.figure.Figure` instance the artist resides in, or None."""
		return self._figure if self._figure is not _tombstone else None

		@figure.setter
		def figure(self, new_figure):
		if (new_figure is not None and self._figure is not None
		and new_figure != self._figure and new_figure is not True):
		if self._figure is _tombstone:
		extra = (
		f"The artist {self!r} has had its Figure reset to None " +
		"but was previously included in one."
		)
		else:
		extra = (
		f"The artist {self!r} is currently in {self._figure!r}."
		)
		raise ValueError("Can not reset the figure. You are probably " +
		"trying to re-use an artist in more than one " +
		"Figure which is not supported. " +
		extra
		)
		if self._figure is not None and new_figure is None:
		new_figure = _tombstone
		self._figure = new_figure

		@property
		def stale(self):
		"""
Expand DownExpand Up		@@ -738,14 +783,6 @@ def set_figure(self, fig):
		# if this is a no-op just return
		if self.figure is fig:
		return
		# if we currently have a figure (the case of both `self.figure`
		# and fig being none is taken care of above) we then user is
		# trying to change the figure an artist is associated with which
		# is not allowed for the same reason as adding the same instance
		# to more than one Axes
		if self.figure is not None:
		raise RuntimeError("Can not put single artist in "
		"more than one figure")
		self.figure = fig
		if self.figure and self.figure is not self:
		self.pchanged()
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -137,6 +137,7 @@ def __init__(self, **kwargs):
		# axis._get_tick_boxes_siblings
		self._align_label_groups = {"x": cbook.Grouper(), "y": cbook.Grouper()}

		self._figure = self
		self._localaxes = [] # track all Axes
		self.artists = []
		self.lines = []
Expand DownExpand Up		@@ -2162,7 +2163,7 @@ def __init__(self, parent, subplotspec, *,

		self._subplotspec = subplotspec
		self._parent = parent
		self.figure = parent.figure
		self._figure = parent.figure

		# subfigures use the parent axstack
		self._axstack = parent._axstack
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -562,3 +562,36 @@ def draw(self, renderer, extra):

		assert 'aardvark' == art.draw(renderer, 'aardvark')
		assert 'aardvark' == art.draw(renderer, extra='aardvark')


		def test_no_reset():
		fig, (ax1, ax2) = plt.subplots(2)
		fig2 = plt.figure()
		ln, = ax1.plot(range(5))
		with pytest.raises(
		ValueError, match=f"The artist {ln!r} is currently in {ax1!r}"
		):
		ax2.add_line(ln)
		with pytest.raises(
		ValueError, match=f"The artist {ln!r} is currently in {ax1!r}"
		):
		ln.axes = ax2
		with pytest.raises(
		ValueError, match=f"The artist {ln!r} is currently in {fig!r}"
		):
		ln.figure = fig2

		ln.remove()
		assert ln.figure is None
		assert ln.axes is None
		with pytest.raises(
		ValueError, match=f"The artist {ln!r} has had its Figure reset "
		):
		ax2.add_line(ln)
		with pytest.raises(
		ValueError, match=f"The artist {ln!r} has had its Axes reset "
		):
		ln.axes = ax2

		assert ln.axes is None
		assert ln.figure is None
Original file line number	Diff line number	Diff line change
Expand Up		@@ -103,8 +103,9 @@ def test_offsetbox_loc_codes():
		'center': 10,
		}
		fig, ax = plt.subplots()
		da = DrawingArea(100, 100)

		for code in codes:
		da = DrawingArea(100, 100)
		anchored_box = AnchoredOffsetbox(loc=code, child=da)
		ax.add_artist(anchored_box)
		fig.canvas.draw()
Expand Down