Simplified logic in _update_label_position to use the bounding box of all ticklabels and axis spine for use in label placement

Author: cimarronm

lib/matplotlib/axis.py

@@ -1569,9 +1569,8 @@ def set_ticks(self, ticks, minor=False):
 
     def _update_label_position(self, bboxes, bboxes2):
         """
-        Update the label position based on the sequence of bounding
-        boxes of all the ticklabels or using the axis spines if no
-        ticklabels are present
+        Update the label position based on the the bounding box enclosing
+        all the ticklabels and axis spine
         """
         raise NotImplementedError('Derived must override')
 
@@ -1726,33 +1725,30 @@ def set_label_position(self, position):
 
     def _update_label_position(self, bboxes, bboxes2):
         """
-        Update the label position based on the sequence of bounding
-        boxes of all the ticklabels or using the axis spines if no
-        ticklabels are present
+        Update the label position based on the the bounding box enclosing
+        all the ticklabels and axis spine
         """
         if not self._autolabelpos:
             return
         x, y = self.label.get_position()
         if self.label_position == 'bottom':
-            if not len(bboxes):
-                bottom = (self.axes.spines['bottom'].get_transform().
-                          transform_path(self.axes.spines['bottom'].
-                                         get_path()).get_extents().ymin)
-            else:
-                bbox = mtransforms.Bbox.union(bboxes)
-                bottom = bbox.y0
+            spinebbox = (self.axes.spines['bottom'].get_transform().
+                         transform_path(self.axes.spines['bottom'].
+                                        get_path()).get_extents())
+            bbox = mtransforms.Bbox.union(bboxes + [spinebbox])
+            bottom = bbox.y0
+
             self.label.set_position(
                 (x, bottom - self.labelpad * self.figure.dpi / 72.0)
             )
 
         else:
-            if not len(bboxes2):
-                top = (self.axes.spines['top'].get_transform().
-                       transform_path(self.axes.spines['top'].
-                                      get_path()).get_extents().ymax)
-            else:
-                bbox = mtransforms.Bbox.union(bboxes2)
-                top = bbox.y1
+            spinebbox = (self.axes.spines['top'].get_transform().
+                         transform_path(self.axes.spines['top'].
+                                        get_path()).get_extents())
+            bbox = mtransforms.Bbox.union(bboxes2 + [spinebbox])
+            top = bbox.y1
+
             self.label.set_position(
                 (x, top + self.labelpad * self.figure.dpi / 72.0)
             )
@@ -2037,34 +2033,29 @@ def set_label_position(self, position):
 
     def _update_label_position(self, bboxes, bboxes2):
         """
-        Update the label position based on the sequence of bounding
-        boxes of all the ticklabels or using the axis spines if no
-        ticklabels are present
+        Update the label position based on the the bounding box enclosing
+        all the ticklabels and axis spine
         """
         if not self._autolabelpos:
             return
         x, y = self.label.get_position()
         if self.label_position == 'left':
-            if not len(bboxes):
-                left = (self.axes.spines['left'].get_transform().
-                        transform_path(self.axes.spines['left'].
-                                       get_path()).get_extents().xmin)
-            else:
-                bbox = mtransforms.Bbox.union(bboxes)
-                left = bbox.x0
+            spinebbox = (self.axes.spines['left'].get_transform().
+                         transform_path(self.axes.spines['left'].
+                                        get_path()).get_extents())
+            bbox = mtransforms.Bbox.union(bboxes + [spinebbox])
+            left = bbox.x0
 
             self.label.set_position(
                 (left - self.labelpad * self.figure.dpi / 72.0, y)
             )
 
         else:
-            if not len(bboxes2):
-                right = (self.axes.spines['right'].get_transform().
+            spinebbox = (self.axes.spines['right'].get_transform().
                          transform_path(self.axes.spines['right'].
-                                        get_path()).get_extents().xmax)
-            else:
-                bbox = mtransforms.Bbox.union(bboxes2)
-                right = bbox.x1
+                                        get_path()).get_extents())
+            bbox = mtransforms.Bbox.union(bboxes2 + [spinebbox])
+            right = bbox.x1
 
             self.label.set_position(
                 (right + self.labelpad * self.figure.dpi / 72.0, y)