Fix volume response when capping volume

docs/changes.rst

@@ -32,6 +32,12 @@ v0.7.0 (in development)
 - Fix crash on mismatching quotation in ``list`` MPD queries. (Fixes:
   :issue:`137`)
 
+- Volume is now reported to be the same as the volume was set to, also when
+  internal rounding have been done due to
+  :attr:`mopidy.settings.MIXER_MAX_VOLUME` has been set to cap the volume. This
+  should make it possible to manage capped volume from clients that only
+  increase volume with one step at a time, like ncmpcpp does.
+
 
 v0.6.1 (2011-12-28)
 ===================

mopidy/mixers/base.py

@@ -21,19 +21,32 @@ class BaseMixer(object):
         Integer in range [0, 100]. :class:`None` if unknown. Values below 0 is
         equal to 0. Values above 100 is equal to 100.
         """
+        if not hasattr(self, '_user_volume'):
+            self._user_volume = 0
         volume = self.get_volume()
         if volume is None:
             return None
-        return int(volume / self.amplification_factor)
+        elif not self.amplification_factor < 1:
+            return volume
+        else:
+            user_volume = int(volume / self.amplification_factor)
+            if (user_volume - 1) <= self._user_volume <= (user_volume + 1):
+                return self._user_volume
+            else:
+                return user_volume
 
     @volume.setter
     def volume(self, volume):
-        volume = int(int(volume) * self.amplification_factor)
+        if not hasattr(self, '_user_volume'):
+            self._user_volume = 0
+        volume = int(volume)
         if volume < 0:
             volume = 0
         elif volume > 100:
             volume = 100
-        self.set_volume(volume)
+        self._user_volume = volume
+        real_volume = int(volume * self.amplification_factor)
+        self.set_volume(real_volume)
         self._trigger_volume_changed()
 
     def get_volume(self):

tests/mixers/dummy_test.py

@@ -4,7 +4,7 @@ from tests import unittest
 from tests.mixers.base_test import BaseMixerTest
 
 
-class DenonMixerTest(BaseMixerTest, unittest.TestCase):
+class DummyMixerTest(BaseMixerTest, unittest.TestCase):
     mixer_class = DummyMixer
 
     def test_set_volume_is_capped(self):
@@ -16,3 +16,8 @@ class DenonMixerTest(BaseMixerTest, unittest.TestCase):
         self.mixer.amplification_factor = 0.5
         self.mixer._volume = 50
         self.assertEquals(self.mixer.volume, 100)
+
+    def test_get_volume_get_the_same_number_as_was_set(self):
+        self.mixer.amplification_factor = 0.5
+        self.mixer.volume = 13
+        self.assertEquals(self.mixer.volume, 13)