core: Add playlist to playlist_changed() event

docs/changes.rst

@@ -121,6 +121,9 @@ backends:
   triggered :meth:`mopidy.core.CoreListener.playlist_changed`, which is
   intended for stored playlists, not the tracklist.
 
+- The event :meth:`mopidy.core.CoreListener.playlist_changed` has been changed
+  to include the playlist that was changed.
+
 **Bug fixes**
 
 - :issue:`218`: The MPD commands ``listplaylist`` and ``listplaylistinfo`` now

mopidy/core/listener.py

@@ -92,11 +92,14 @@ class CoreListener(object):
         """
         pass
 
-    def playlist_changed(self):
+    def playlist_changed(self, playlist):
         """
         Called whenever a playlist is changed.
 
         *MAY* be implemented by actor.
+
+        :param playlist: the changed playlist
+        :type playlist: :class:`mopidy.models.Playlist`
         """
         pass
 

tests/core/listener_test.py

@@ -1,7 +1,7 @@
 from __future__ import unicode_literals
 
 from mopidy.core import CoreListener, PlaybackState
-from mopidy.models import Track
+from mopidy.models import Playlist, Track
 
 from tests import unittest
 
@@ -30,7 +30,7 @@ class CoreListenerTest(unittest.TestCase):
         self.listener.tracklist_changed()
 
     def test_listener_has_default_impl_for_playlist_changed(self):
-        self.listener.playlist_changed()
+        self.listener.playlist_changed(Playlist())
 
     def test_listener_has_default_impl_for_options_changed(self):
         self.listener.options_changed()