Implement _playback_single and add 'single' field to BasePlaybackController

mopidy/backends/__init__.py

@@ -249,6 +249,12 @@ class BasePlaybackController(object):
     #:     The current track is played once.
     repeat = False
 
+    #: :class:`True`
+    #:     Playback is stopped after current song, unless in repeat mode.
+    #: :class:`False`
+    #:     Playback continues after current song.
+    single = False
+
     def __init__(self, backend, mixer=alsaaudio.Mixer):
         self.backend = backend
         self._state = self.STOPPED

mopidy/mpd/handler.py

@@ -888,11 +888,10 @@ class MpdHandler(object):
             single is activated, playback is stopped after current song, or
             song is repeated if the ``repeat`` mode is enabled.
         """
-        state = int(state)
-        if state:
-            raise MpdNotImplemented # TODO
+        if int(state):
+            self.backend.playback.single = True
         else:
-            raise MpdNotImplemented # TODO
+            self.backend.playback.single = False
 
     @handle_pattern(r'^stop$')
     def _playback_stop(self):

tests/mpd/handlertest.py

@@ -371,11 +371,13 @@ class PlaybackOptionsHandlerTest(unittest.TestCase):
 
     def test_single_off(self):
         result = self.h.handle_request(u'single "0"')
-        self.assert_(u'ACK Not implemented' in result)
+        self.assertFalse(self.b.playback.single)
+        self.assert_(u'OK' in result)
 
     def test_single_on(self):
         result = self.h.handle_request(u'single "1"')
-        self.assert_(u'ACK Not implemented' in result)
+        self.assertTrue(self.b.playback.single)
+        self.assert_(u'OK' in result)
 
     def test_replay_gain_mode_off(self):
         result = self.h.handle_request(u'replay_gain_mode "off"')