matplotlib · jklymak · Jan 9, 2022 · Jan 8, 2022 · Jan 8, 2022
diff --git a/doc/api/next_api_changes/deprecations/22134-OG.rst b/doc/api/next_api_changes/deprecations/22134-OG.rst
@@ -0,0 +1,5 @@
+Modules ``tight_bbox`` and ``tight_layout`` deprecated
+------------------------------------------------------
+
+The modules ``matplotlib.tight_bbox`` and ``matplotlib.tight_layout`` are
+considered internal and public access is deprecated.
diff --git a/doc/api/prev_api_changes/api_changes_1.4.x.rst b/doc/api/prev_api_changes/api_changes_1.4.x.rst
@@ -149,9 +149,9 @@ original location:
   ``drawRect`` from ``FigureCanvasQTAgg``; they were always an
   implementation detail of the (preserved) ``drawRectangle()`` function.
 
-* The function signatures of `.tight_bbox.adjust_bbox` and
-  `.tight_bbox.process_figure_for_rasterizing` have been changed. A new
-  *fixed_dpi* parameter allows for overriding the ``figure.dpi`` setting
+* The function signatures of ``matplotlib.tight_bbox.adjust_bbox`` and
+  ``matplotlib.tight_bbox.process_figure_for_rasterizing`` have been changed.
+  A new *fixed_dpi* parameter allows for overriding the ``figure.dpi`` setting
   instead of trying to deduce the intended behaviour from the file format.
 
 * Added support for horizontal/vertical axes padding to

diff --git a/doc/api/prev_api_changes/api_changes_2.2.0.rst b/doc/api/prev_api_changes/api_changes_2.2.0.rst
@@ -159,7 +159,7 @@ If `.MovieWriterRegistry` can't find the requested `.MovieWriter`, a
 more helpful `RuntimeError` message is now raised instead of the
 previously raised `KeyError`.
 
-`~.tight_layout.auto_adjust_subplotpars` now raises `ValueError`
+``matplotlib.tight_layout.auto_adjust_subplotpars`` now raises `ValueError`
 instead of `RuntimeError` when sizes of input lists don't match
 
 

diff --git a/doc/api/prev_api_changes/api_changes_3.0.1.rst b/doc/api/prev_api_changes/api_changes_3.0.1.rst
@@ -1,10 +1,10 @@
 API Changes for 3.0.1
 =====================
 
-`.tight_layout.auto_adjust_subplotpars` can return ``None`` now if the new
-subplotparams will collapse axes to zero width or height.  This prevents
-``tight_layout`` from being executed.  Similarly
-`.tight_layout.get_tight_layout_figure` will return None.
+``matplotlib.tight_layout.auto_adjust_subplotpars`` can return ``None`` now if
+the new subplotparams will collapse axes to zero width or height.
+This prevents ``tight_layout`` from being executed.  Similarly
+``matplotlib.tight_layout.get_tight_layout_figure`` will return None.
 
 To improve import (startup) time, private modules are now imported lazily.
 These modules are no longer available at these locations:

diff --git a/lib/matplotlib/_tight_bbox.py b/lib/matplotlib/_tight_bbox.py
@@ -0,0 +1,85 @@
+"""
+Helper module for the *bbox_inches* parameter in `.Figure.savefig`.
+"""
+
+from matplotlib.transforms import Bbox, TransformedBbox, Affine2D
+
+
+def adjust_bbox(fig, bbox_inches, fixed_dpi=None):
+    """
+    Temporarily adjust the figure so that only the specified area
+    (bbox_inches) is saved.
+
+    It modifies fig.bbox, fig.bbox_inches,
+    fig.transFigure._boxout, and fig.patch.  While the figure size
+    changes, the scale of the original figure is conserved.  A
+    function which restores the original values are returned.
+    """
+    origBbox = fig.bbox
+    origBboxInches = fig.bbox_inches
+    orig_tight_layout = fig.get_tight_layout()
+    _boxout = fig.transFigure._boxout
+
+    fig.set_tight_layout(False)
+
+    old_aspect = []
+    locator_list = []
+    sentinel = object()
+    for ax in fig.axes:
+        locator_list.append(ax.get_axes_locator())
+        current_pos = ax.get_position(original=False).frozen()
+        ax.set_axes_locator(lambda a, r, _pos=current_pos: _pos)
+        # override the method that enforces the aspect ratio on the Axes
+        if 'apply_aspect' in ax.__dict__:
+            old_aspect.append(ax.apply_aspect)
+        else:
+            old_aspect.append(sentinel)
+        ax.apply_aspect = lambda pos=None: None
+
+    def restore_bbox():
+        for ax, loc, aspect in zip(fig.axes, locator_list, old_aspect):
+            ax.set_axes_locator(loc)
+            if aspect is sentinel:
+                # delete our no-op function which un-hides the original method
+                del ax.apply_aspect
+            else:
+                ax.apply_aspect = aspect
+
+        fig.bbox = origBbox
+        fig.bbox_inches = origBboxInches
+        fig.set_tight_layout(orig_tight_layout)
+        fig.transFigure._boxout = _boxout
+        fig.transFigure.invalidate()
+        fig.patch.set_bounds(0, 0, 1, 1)
+
+    if fixed_dpi is None:
+        fixed_dpi = fig.dpi
+    tr = Affine2D().scale(fixed_dpi)
+    dpi_scale = fixed_dpi / fig.dpi
+
+    fig.bbox_inches = Bbox.from_bounds(0, 0, *bbox_inches.size)
+    x0, y0 = tr.transform(bbox_inches.p0)
+    w1, h1 = fig.bbox.size * dpi_scale
+    fig.transFigure._boxout = Bbox.from_bounds(-x0, -y0, w1, h1)
+    fig.transFigure.invalidate()
+
+    fig.bbox = TransformedBbox(fig.bbox_inches, tr)
+
+    fig.patch.set_bounds(x0 / w1, y0 / h1,
+                         fig.bbox.width / w1, fig.bbox.height / h1)
+
+    return restore_bbox
+
+
+def process_figure_for_rasterizing(fig, bbox_inches_restore, fixed_dpi=None):
+    """
+    A function that needs to be called when figure dpi changes during the
+    drawing (e.g., rasterizing).  It recovers the bbox and re-adjust it with
+    the new dpi.
+    """
+
+    bbox_inches, restore_bbox = bbox_inches_restore
+    restore_bbox()
+    r = adjust_bbox(fig, bbox_inches, fixed_dpi)
+
+    return bbox_inches, r