Add mixer for OS X which uses osascript

mopidy/mixers/osa.py

@@ -0,0 +1,15 @@
+from subprocess import Popen, PIPE
+
+from mopidy.mixers import BaseMixer
+
+class OsaMixer(BaseMixer):
+    def _get_volume(self):
+        try:
+            return int(Popen(
+                ['osascript', '-e', 'output volume of (get volume settings)'],
+                stdout=PIPE).communicate()[0])
+        except ValueError:
+            return None
+
+    def _set_volume(self, volume):
+        Popen(['osascript', '-e', 'set volume output volume %d' % volume])

mopidy/settings/default.py

@@ -31,12 +31,18 @@ CONSOLE_LOG_FORMAT = u'%(levelname)-8s %(asctime)s [%(threadName)s] %(name)s\n
 #:
 #:     MIXER = u'mopidy.mixers.alsa.AlsaMixer'
 #:
+#: Default on OS X::
+#:
+#:     MIXER = u'mopidy.mixers.osa.OsaMixer'
+#:
 #: Default on other operating systems::
 #:
 #:     MIXER = u'mopidy.mixers.dummy.DummyMixer'
 MIXER = u'mopidy.mixers.dummy.DummyMixer'
 if sys.platform == 'linux2':
     MIXER = u'mopidy.mixers.alsa.AlsaMixer'
+elif sys.platform == 'darwin':
+    MIXER = u'mopidy.mixers.osa.OsaMixer'
 
 #: Which address Mopidy should bind to. Examples:
 #: