Send old and new state to playback_state_changed listeners

mopidy/core/playback.py

@@ -290,7 +290,7 @@ class PlaybackController(object):
         (old_state, self._state) = (self.state, new_state)
         logger.debug(u'Changing state: %s -> %s', old_state, new_state)
 
-        self._trigger_playback_state_changed()
+        self._trigger_playback_state_changed(old_state, new_state)
 
         # FIXME play_time stuff assumes backend does not have a better way of
         # handeling this stuff :/
@@ -544,9 +544,10 @@ class PlaybackController(object):
             track=self.current_track,
             time_position=self.time_position)
 
-    def _trigger_playback_state_changed(self):
+    def _trigger_playback_state_changed(self, old_state, new_state):
         logger.debug(u'Triggering playback state change event')
-        BackendListener.send('playback_state_changed')
+        BackendListener.send('playback_state_changed',
+            old_state=old_state, new_state=new_state)
 
     def _trigger_options_changed(self):
         logger.debug(u'Triggering options changed event')

mopidy/frontends/mpd/__init__.py

@@ -51,7 +51,7 @@ class MpdFrontend(actor.ThreadingActor, listeners.BackendListener):
             'kwargs': {},
         }, target_class=MpdSession)
 
-    def playback_state_changed(self):
+    def playback_state_changed(self, old_state, new_state):
         self.send_idle('player')
 
     def playlist_changed(self):

mopidy/listeners.py

@@ -74,11 +74,16 @@ class BackendListener(object):
         """
         pass
 
-    def playback_state_changed(self):
+    def playback_state_changed(self, old_state, new_state):
         """
         Called whenever playback state is changed.
 
         *MAY* be implemented by actor.
+
+        :param old_state: the state before the change
+        :type old_state: string from :class:`mopidy.core.PlaybackState` field
+        :param new_state: the state after the change
+        :type new_state: string from :class:`mopidy.core.PlaybackState` field
         """
         pass
 

tests/listeners_test.py

@@ -1,3 +1,4 @@
+from mopidy.core import PlaybackState
 from mopidy.listeners import BackendListener
 from mopidy.models import Track
 
@@ -21,7 +22,8 @@ class BackendListenerTest(unittest.TestCase):
         self.listener.track_playback_ended(Track(), 0)
 
     def test_listener_has_default_impl_for_playback_state_changed(self):
-        self.listener.playback_state_changed()
+        self.listener.playback_state_changed(
+            PlaybackState.STOPPED, PlaybackState.PLAYING)
 
     def test_listener_has_default_impl_for_playlist_changed(self):
         self.listener.playlist_changed()