MNT: Rename callbacksSM to callbacks

This makes the code more consistent throughout with objects
having a `callbacks` attribute, rather than associating a name
with them on the end.

Author: greglucas

doc/api/next_api_changes/deprecations/20799-GL.rst

@@ -0,0 +1,3 @@
+``ScalarMappable.callbacksSM``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+is deprecated. Use ``ScalarMappable.callbacks`` instead.

doc/api/next_api_changes/removals/19552-GL.rst

@@ -2,4 +2,4 @@ ScalarMappable update checkers
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 ``ScalarMappable.update_dict``, ``ScalarMappable.add_checker()``, and
 ``ScalarMappable.check_update()`` have been removed. A callback can
-be registered in ``ScalarMappable.callbacksSM`` to be notified of updates.
+be registered in ``ScalarMappable.callbacks`` to be notified of updates.

examples/images_contours_and_fields/multi_image.py

@@ -47,7 +47,7 @@ def update(changed_image):
 
 
 for im in images:
-    im.callbacksSM.connect('changed', update)
+    im.callbacks.connect('changed', update)
 
 plt.show()
 

lib/matplotlib/axes/_axes.py

@@ -4923,7 +4923,7 @@ def on_changed(collection):
             vbar.set_cmap(collection.get_cmap())
             vbar.set_clim(collection.get_clim())
 
-        collection.callbacksSM.connect('changed', on_changed)
+        collection.callbacks.connect('changed', on_changed)
 
         return collection
 

lib/matplotlib/cm.py

@@ -263,7 +263,10 @@ def __init__(self, norm=None, cmap=None):
         self.set_cmap(cmap)  # The Colormap instance of this ScalarMappable.
         #: The last colorbar associated with this ScalarMappable. May be None.
         self.colorbar = None
-        self.callbacksSM = cbook.CallbackRegistry()
+        self.callbacks = cbook.CallbackRegistry()
+
+    callbacksSM = _api.deprecated("3.5", alternative="callbacks")(
+        property(lambda self: self.callbacks))
 
     def _scale_norm(self, norm, vmin, vmax):
         """
@@ -495,5 +498,5 @@ def changed(self):
         Call this whenever the mappable is changed to notify all the
         callbackSM listeners to the 'changed' signal.
         """
-        self.callbacksSM.process('changed', self)
+        self.callbacks.process('changed', self)
         self.stale = True

lib/matplotlib/colorbar.py

@@ -404,7 +404,7 @@ def __init__(self, ax, mappable=None, *, cmap=None,
             alpha = mappable.get_alpha()
 
         mappable.colorbar = self
-        mappable.colorbar_cid = mappable.callbacksSM.connect(
+        mappable.colorbar_cid = mappable.callbacks.connect(
             'changed', self.update_normal)
 
         _api.check_in_list(
@@ -981,7 +981,7 @@ def remove(self):
         """
         self.ax.remove()
 
-        self.mappable.callbacksSM.disconnect(self.mappable.colorbar_cid)
+        self.mappable.callbacks.disconnect(self.mappable.colorbar_cid)
         self.mappable.colorbar = None
         self.mappable.colorbar_cid = None