Additional options when muted for the PulseAudio-Slider module:

- Add "muted" class for styling the muted state.
- Add "zero-on-mute" boolean option to control slider position
  when muted.
- Add "unmute-on-volume-change" boolean option to control whether
  to automatically unmute when the volume changes.

include/util/audio_backend.hpp

@@ -14,6 +14,11 @@
 
 namespace waybar::util {
 
+enum class PulseaudioTarget {
+  Sink,
+  Source,
+};
+
 class AudioBackend {
  private:
   static void subscribeCb(pa_context*, pa_subscription_event_type_t, uint32_t, void*);
@@ -92,7 +97,11 @@ class AudioBackend {
   void toggleSourceMute();
   void toggleSourceMute(bool);
 
+  uint16_t getVolume(PulseaudioTarget) const;
+  bool getMuted(PulseaudioTarget) const;
+  void unmute(PulseaudioTarget);
+
   bool isBluetooth();
 };
 
-}  // namespace waybar::util
+}  // namespace waybar::util