Redo colorbar overhaul.

Previous overhaul packaged an inner and outer axes in a container
"ColorbarAxes" and tried to dispatch methods between them.

This overhaul takes the _much_ simpler approach of resizing the
image using a custom _axes_locator that a) calls any existing locator
b) or just uses the axes default position. The custom _axes_locator
then shrinks the axes in the appropriate direction to make room for
extend tri/rectangles.  As with the previous fix, the extend
tri/rectangles are drawn as patches in axes co-ordinates, rather than
pcolormesh in "data" co-ordinates.

Author: jklymak

doc/api/next_api_changes/behavior/20054-JMK.rst

@@ -1,15 +1,3 @@
-Axes used to make colorbar now wrapped
-======================================
-
-The axes used to place a colorbar is now wrapped by a new parent class
-(``ColorbarAxes``) when the colorbar is created::
-
-    cb = fig.colorbar(im, cax=cax)
-
-This means that ``cb.ax`` is no longer the same object as ``cax``. However, 
-we map all the methods from ``cb.ax`` onto ``cax`` so ``cax`` should remain 
-functionally the same as ``cb.ax``.  
-
 Colorbar lines no longer clipped
 ================================
 

lib/matplotlib/_constrained_layout.py

@@ -575,7 +575,11 @@ def _reposition_colorbar(cbax, renderer, *, offset=None):
     pbcb = trans_fig_to_subfig.transform_bbox(pbcb)
     cbax.set_transform(fig.transSubfigure)
     cbax._set_position(pbcb)
-    cbax.set_aspect(aspect, anchor=anchor, adjustable='box')
+    cbax.set_anchor(anchor)
+    if location in ['bottom', 'top']:
+        aspect = 1 / aspect
+    cbax.set_box_aspect(aspect)
+    cbax.set_aspect('auto')
     return offset
 
 

lib/matplotlib/axes/_base.py

@@ -2380,6 +2380,8 @@ def _update_patch_limits(self, patch):
             return
         patch_trf = patch.get_transform()
         updatex, updatey = patch_trf.contains_branch_seperately(self.transData)
+        if not (updatex or updatey):
+            return
         if self.name != "rectilinear":
             # As in _update_line_limits, but for axvspan.
             if updatex and patch_trf == self.get_yaxis_transform():