Give the backends an audio proxy on construction

mopidy/__main__.py

@@ -51,8 +51,8 @@ def main():
         setup_logging(options.verbosity_level, options.save_debug_log)
         check_old_folders()
         setup_settings(options.interactive)
-        setup_audio()
-        setup_backend()
+        audio = setup_audio()
+        setup_backend(audio)
         setup_frontends()
         loop.run()
     except SettingsError as e:
@@ -118,14 +118,15 @@ def setup_settings(interactive):
 
 
 def setup_audio():
-    Audio.start()
+    return Audio.start().proxy()
 
 
 def stop_audio():
     stop_actors_by_class(Audio)
 
-def setup_backend():
-    get_class(settings.BACKENDS[0]).start()
+
+def setup_backend(audio):
+    get_class(settings.BACKENDS[0]).start(audio=audio)
 
 
 def stop_backend():

mopidy/backends/base/__init__.py

@@ -4,6 +4,12 @@ from .stored_playlists import BaseStoredPlaylistsProvider
 
 
 class Backend(object):
+    #: Actor proxy to an instance of :class:`mopidy.audio.Audio`.
+    #:
+    #: Should be passed to the backend constructor as the kwarg ``audio``,
+    #: which will then set this field.
+    audio = None
+
     #: The current playlist controller. An instance of
     #: :class:`mopidy.backends.base.CurrentPlaylistController`.
     current_playlist = None
@@ -22,3 +28,6 @@ class Backend(object):
 
     #: List of URI schemes this backend can handle.
     uri_schemes = []
+
+    def __init__(self, audio=None):
+        self.audio = audio

mopidy/backends/local/__init__.py

@@ -32,7 +32,7 @@ class LocalBackend(ThreadingActor, base.Backend):
     """
 
     def __init__(self, *args, **kwargs):
-        super(LocalBackend, self).__init__(*args, **kwargs)
+        base.Backend.__init__(self, *args, **kwargs)
 
         self.current_playlist = core.CurrentPlaylistController(backend=self)
 
@@ -50,14 +50,6 @@ class LocalBackend(ThreadingActor, base.Backend):
 
         self.uri_schemes = [u'file']
 
-        self.audio = None
-
-    def on_start(self):
-        audio_refs = ActorRegistry.get_by_class(audio.Audio)
-        assert len(audio_refs) == 1, \
-            'Expected exactly one running Audio instance.'
-        self.audio = audio_refs[0].proxy()
-
 
 class LocalStoredPlaylistsProvider(base.BaseStoredPlaylistsProvider):
     def __init__(self, *args, **kwargs):

mopidy/backends/spotify/__init__.py

@@ -47,7 +47,7 @@ class SpotifyBackend(ThreadingActor, base.Backend):
         from .playback import SpotifyPlaybackProvider
         from .stored_playlists import SpotifyStoredPlaylistsProvider
 
-        super(SpotifyBackend, self).__init__(*args, **kwargs)
+        base.Backend.__init__(self, *args, **kwargs)
 
         self.current_playlist = core.CurrentPlaylistController(backend=self)
 
@@ -66,7 +66,6 @@ class SpotifyBackend(ThreadingActor, base.Backend):
 
         self.uri_schemes = [u'spotify']
 
-        self.audio = None
         self.spotify = None
 
         # Fail early if settings are not present
@@ -74,11 +73,6 @@ class SpotifyBackend(ThreadingActor, base.Backend):
         self.password = settings.SPOTIFY_PASSWORD
 
     def on_start(self):
-        audio_refs = ActorRegistry.get_by_class(audio.Audio)
-        assert len(audio_refs) == 1, \
-            'Expected exactly one running Audio instance.'
-        self.audio = audio_refs[0].proxy()
-
         logger.info(u'Mopidy uses SPOTIFY(R) CORE')
         self.spotify = self._connect()