1 files changed, 29 insertions, 0 deletions
diff --git a/solo-tool-project/src/solo_tool/notifier.py b/solo-tool-project/src/solo_tool/notifier.py
new file mode 100644
index 0000000..9f445b6
--- /dev/null
+++ b/solo-tool-project/src/solo_tool/notifier.py
@@ -0,0 +1,29 @@
+class Notifier:
+    PLAYING_STATE_EVENT = 0
+    PLAYBACK_VOLUME_EVENT = 1
+    PLAYBACK_RATE_EVENT = 2
+    CURRENT_SONG_EVENT = 3
+    CURRENT_AB_EVENT = 4
+    AB_LIMIT_ENABLED_EVENT = 5
+
+    def __init__(self, player):
+        self._callbacks = dict()
+        self._player = player
+        self._player.setPlayingStateChangedCallback(self._playingStateChangedCallback)
+        self._player.setPlaybackVolumeChangedCallback(self._playbackVolumeChangedCallback)
+
+    def registerCallback(self, event, callback):
+        if event not in self._callbacks:
+            self._callbacks[event] = list()
+        self._callbacks[event].append(callback)
+
+    def notify(self, event, value):
+        for callback in self._callbacks.get(event, list()):
+            callback(value)
+
+    def _playingStateChangedCallback(self, *args):
+        self.notify(Notifier.PLAYING_STATE_EVENT, self._player.isPlaying())
+
+    def _playbackVolumeChangedCallback(self, *args):
+        self.notify(Notifier.PLAYBACK_VOLUME_EVENT, self._player.getPlaybackVolume())
+