Implement improved set_volume_level method (#150)

* Implement revised 'set_volume_level' method

* Update 'set_volume_level' method

* Python 2 fix

androidtv/basetv.py

@@ -1090,54 +1090,29 @@ def key_z(self):
     #                              volume methods                             #
     #                                                                         #
     # ======================================================================= #
-    def set_volume_level(self, volume_level, current_volume_level=None):
+    def set_volume_level(self, volume_level):
         """Set the volume to the desired level.
 
-        .. note::
-
-           This method works by sending volume up/down commands with a 1 second pause in between.  Without this pause,
-           the device will do a quick power cycle.  This is the most robust solution I've found so far.
-
-
         Parameters
         ----------
         volume_level : float
             The new volume level (between 0 and 1)
-        current_volume_level : float, None
-            The current volume level (between 0 and 1); if it is not provided, it will be determined
 
         Returns
         -------
         float, None
             The new volume level (between 0 and 1), or ``None`` if ``self.max_volume`` could not be determined
 
         """
-        # if necessary, determine the current volume and/or the max volume
-        if current_volume_level is None or not self.max_volume:
-            current_volume = self.volume
-        else:
-            current_volume = min(max(round(self.max_volume * current_volume_level), 0.), self.max_volume)
-
-        # if `self.max_volume` or `current_volume` could not be determined, do not proceed
-        if not self.max_volume or current_volume is None:
-            return None
-
-        new_volume = min(max(round(self.max_volume * volume_level), 0.), self.max_volume)
-
-        # Case 1: the new volume is the same as the current volume
-        if new_volume == current_volume:
-            return new_volume / self.max_volume
-
-        # Case 2: the new volume is less than the current volume
-        if new_volume < current_volume:
-            cmd = "(" + " && sleep 1 && ".join(["input keyevent {0}".format(constants.KEY_VOLUME_DOWN)] * int(current_volume - new_volume)) + ") &"
+        # if necessary, determine the max volume
+        if not self.max_volume:
+            _ = self.volume
+            if not self.max_volume:
+                return None
 
-        # Case 3: the new volume is greater than the current volume
-        else:
-            cmd = "(" + " && sleep 1 && ".join(["input keyevent {0}".format(constants.KEY_VOLUME_UP)] * int(new_volume - current_volume)) + ") &"
+        new_volume = int(min(max(round(self.max_volume * volume_level), 0.), self.max_volume))
 
-        # send the volume down/up commands
-        self._adb.shell(cmd)
+        self._adb.shell("media volume --show --stream 3 --set {}".format(new_volume))
 
         # return the new volume level
         return new_volume / self.max_volume

tests/test_androidtv.py

@@ -712,23 +712,17 @@ def test_set_volume_level(self):
         with patchers.patch_shell(STREAM_MUSIC_ON)[self.PATCH_KEY]:
             new_volume_level = self.atv.set_volume_level(0.5)
             self.assertEqual(new_volume_level, 0.5)
-            self.assertEqual(getattr(self.atv._adb, self.ADB_ATTR).shell_cmd, "(input keyevent 24 && sleep 1 && input keyevent 24 && sleep 1 && input keyevent 24 && sleep 1 && input keyevent 24 && sleep 1 && input keyevent 24 && sleep 1 && input keyevent 24 && sleep 1 && input keyevent 24 && sleep 1 && input keyevent 24) &")
+            self.assertEqual(getattr(self.atv._adb, self.ADB_ATTR).shell_cmd, "media volume --show --stream 3 --set 30")
 
         with patchers.patch_shell('')[self.PATCH_KEY]:
-            new_volume_level = self.atv.set_volume_level(0.5, 22./60)
+            new_volume_level = self.atv.set_volume_level(30./60)
             self.assertEqual(new_volume_level, 0.5)
-            self.assertEqual(getattr(self.atv._adb, self.ADB_ATTR).shell_cmd, "(input keyevent 24 && sleep 1 && input keyevent 24 && sleep 1 && input keyevent 24 && sleep 1 && input keyevent 24 && sleep 1 && input keyevent 24 && sleep 1 && input keyevent 24 && sleep 1 && input keyevent 24 && sleep 1 && input keyevent 24) &")
+            self.assertEqual(getattr(self.atv._adb, self.ADB_ATTR).shell_cmd, "media volume --show --stream 3 --set 30")
 
         with patchers.patch_shell('')[self.PATCH_KEY]:
-            new_volume_level = self.atv.set_volume_level(22./60, 0.5)
+            new_volume_level = self.atv.set_volume_level(22./60)
             self.assertEqual(new_volume_level, 22./60)
-            self.assertEqual(getattr(self.atv._adb, self.ADB_ATTR).shell_cmd, "(input keyevent 25 && sleep 1 && input keyevent 25 && sleep 1 && input keyevent 25 && sleep 1 && input keyevent 25 && sleep 1 && input keyevent 25 && sleep 1 && input keyevent 25 && sleep 1 && input keyevent 25 && sleep 1 && input keyevent 25) &")
-
-        with patchers.patch_shell('')[self.PATCH_KEY]:
-            self.atv.adb_shell('')
-            new_volume_level = self.atv.set_volume_level(22./60, 22./60)
-            self.assertEqual(new_volume_level, 22./60)
-            self.assertEqual(getattr(self.atv._adb, self.ADB_ATTR).shell_cmd, "")
+            self.assertEqual(getattr(self.atv._adb, self.ADB_ATTR).shell_cmd, "media volume --show --stream 3 --set 22")
 
     def test_volume_up(self):
         """Check that the ``volume_up`` method works correctly.