Cleanup span_where.

anntzer · anntzer · commit fb3ea5eea6e0 · 2019-12-19T11:20:44.000+01:00
- Make it a classmethod so that if called through a subclass, that
  subclass is returned.
- Reword a bit the docstring (I think it's the kind of cases where
  non-numpydoc is actually more readable...).
diff --git a/lib/matplotlib/collections.py b/lib/matplotlib/collections.py
@@ -1155,26 +1155,22 @@ def __init__(self, xranges, yrange, **kwargs):
                   (xmin, ymin)] for xmin, xwidth in xranges]
         PolyCollection.__init__(self, verts, **kwargs)
 
-    @staticmethod
-    def span_where(x, ymin, ymax, where, **kwargs):
+    @classmethod
+    def span_where(cls, x, ymin, ymax, where, **kwargs):
         """
-        Create a BrokenBarHCollection to plot horizontal bars from
+        Return a `BrokenBarHCollection` that plots horizontal bars from
         over the regions in *x* where *where* is True.  The bars range
         on the y-axis from *ymin* to *ymax*
 
-        A :class:`BrokenBarHCollection` is returned.  *kwargs* are
-        passed on to the collection.
+        *kwargs* are passed on to the collection.
         """
         xranges = []
         for ind0, ind1 in cbook.contiguous_regions(where):
             xslice = x[ind0:ind1]
             if not len(xslice):
                 continue
             xranges.append((xslice[0], xslice[-1] - xslice[0]))
-
-        collection = BrokenBarHCollection(
-            xranges, [ymin, ymax - ymin], **kwargs)
-        return collection
+        return cls(xranges, [ymin, ymax - ymin], **kwargs)
 
 
 class RegularPolyCollection(_CollectionWithSizes):
