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/modules/pulseaudio_slider.hpp

@@ -6,10 +6,6 @@
 #include "util/audio_backend.hpp"
 namespace waybar::modules {
 
-enum class PulseaudioSliderTarget {
-  Sink,
-  Source,
-};
 
 class PulseaudioSlider : public ASlider {
  public:
@@ -21,7 +17,15 @@ class PulseaudioSlider : public ASlider {
 
  private:
   std::shared_ptr<util::AudioBackend> backend = nullptr;
-  PulseaudioSliderTarget target = PulseaudioSliderTarget::Sink;
+  util::PulseaudioTarget target = util::PulseaudioTarget::Sink;
+
+  bool zero_on_mute = true;
+  bool unmute_on_volume_change = true;
+  // zero_on_mute and unmute_on_volume_change default to true
+  // in order to maintain previous behaviour when using a
+  // config in which these values are undefined
+
+  bool previously_muted = false;
 };
 
-}  // namespace waybar::modules
+}  // namespace waybar::modules