Inherit OffsetBox.get_window_extent.

Adjust OffsetBox.get_window_extent to use get_extent (which is typically
redefined in subclasses) instead of get_extent_offsets (which is not),
and make it check whether the current class' get_offset takes any
arguments or not (which is not consistent, but fixing that requires some
backcompat work).

Also set the offset-getter of AnchoredOffsetbox as a fixed method on the
class, rather than dynamicaly setting in that class' get_extent_offset.

These changes then let us inherit the implementation of
OffsetBox.get_window_extent across most subclasses instead of having to
copy-paste it again and again.

Author: anntzer

lib/matplotlib/offsetbox.py

@@ -350,8 +350,12 @@ def get_window_extent(self, renderer=None):
         # docstring inherited
         if renderer is None:
             renderer = self.figure._get_renderer()
-        w, h, xd, yd, offsets = self.get_extent_offsets(renderer)
-        px, py = self.get_offset(w, h, xd, yd, renderer)
+        w, h, xd, yd = self.get_extent(renderer)
+        # Some subclasses redefine get_offset to take no args.
+        try:
+            px, py = self.get_offset(w, h, xd, yd, renderer)
+        except TypeError:
+            px, py = self.get_offset()
         return mtransforms.Bbox.from_bounds(px - xd, py - yd, w, h)
 
     def draw(self, renderer):
@@ -636,15 +640,6 @@ def get_offset(self):
         """Return offset of the container."""
         return self._offset
 
-    def get_window_extent(self, renderer=None):
-        # docstring inherited
-        if renderer is None:
-            renderer = self.figure._get_renderer()
-        w, h, xd, yd = self.get_extent(renderer)
-        ox, oy = self.get_offset()  # w, h, xd, yd)
-
-        return mtransforms.Bbox.from_bounds(ox - xd, oy - yd, w, h)
-
     def get_extent(self, renderer):
         """Return width, height, xdescent, ydescent of box."""
         dpi_cor = renderer.points_to_pixels(1.)
@@ -773,14 +768,6 @@ def get_offset(self):
         """Return offset of the container."""
         return self._offset
 
-    def get_window_extent(self, renderer=None):
-        # docstring inherited
-        if renderer is None:
-            renderer = self.figure._get_renderer()
-        w, h, xd, yd = self.get_extent(renderer)
-        ox, oy = self.get_offset()
-        return mtransforms.Bbox.from_bounds(ox - xd, oy - yd, w, h)
-
     def get_extent(self, renderer):
         _, h_, d_ = renderer.get_text_width_height_descent(
             "lp", self._text._fontproperties,
@@ -876,14 +863,6 @@ def get_offset(self):
         """Return offset of the container."""
         return self._offset
 
-    def get_window_extent(self, renderer=None):
-        # docstring inherited
-        if renderer is None:
-            renderer = self.figure._get_renderer()
-        w, h, xd, yd = self.get_extent(renderer)
-        ox, oy = self.get_offset()  # w, h, xd, yd)
-        return mtransforms.Bbox.from_bounds(ox - xd, oy - yd, w, h)
-
     def get_extent(self, renderer):
         # clear the offset transforms
         _off = self.offset_transform.get_matrix()  # to be restored later
@@ -1061,26 +1040,14 @@ def set_bbox_to_anchor(self, bbox, transform=None):
         self._bbox_to_anchor_transform = transform
         self.stale = True
 
-    def get_window_extent(self, renderer=None):
+    def get_offset(self, width, height, xdescent, ydescent, renderer):
         # docstring inherited
-        if renderer is None:
-            renderer = self.figure._get_renderer()
-
-        # Update the offset func, which depends on the dpi of the renderer
-        # (because of the padding).
-        fontsize = renderer.points_to_pixels(self.prop.get_size_in_points())
-
-        def _offset(w, h, xd, yd, renderer):
-            bbox = Bbox.from_bounds(0, 0, w, h)
-            pad = self.borderpad * fontsize
-            bbox_to_anchor = self.get_bbox_to_anchor()
-            x0, y0 = _get_anchored_bbox(self.loc, bbox, bbox_to_anchor, pad)
-            return x0 + xd, y0 + yd
-
-        self.set_offset(_offset)
-        w, h, xd, yd = self.get_extent(renderer)
-        ox, oy = self.get_offset(w, h, xd, yd, renderer)
-        return Bbox.from_bounds(ox - xd, oy - yd, w, h)
+        bbox = Bbox.from_bounds(0, 0, width, height)
+        pad = (self.borderpad
+               * renderer.points_to_pixels(self.prop.get_size_in_points()))
+        bbox_to_anchor = self.get_bbox_to_anchor()
+        x0, y0 = _get_anchored_bbox(self.loc, bbox, bbox_to_anchor, pad)
+        return x0 + xdescent, y0 + ydescent
 
     def update_frame(self, bbox, fontsize=None):
         self.patch.set_bounds(bbox.bounds)
@@ -1220,14 +1187,6 @@ def get_offset(self):
     def get_children(self):
         return [self.image]
 
-    def get_window_extent(self, renderer=None):
-        # docstring inherited
-        if renderer is None:
-            renderer = self.figure._get_renderer()
-        w, h, xd, yd = self.get_extent(renderer)
-        ox, oy = self.get_offset()
-        return mtransforms.Bbox.from_bounds(ox - xd, oy - yd, w, h)
-
     def get_extent(self, renderer):
         if self._dpi_cor:  # True, do correction
             dpi_cor = renderer.points_to_pixels(1.)