feat: pulseaudio slider module

include/modules/pulseaudio_slider.hpp

@@ -0,0 +1,27 @@
+#pragma once
+
+#include <memory>
+
+#include "ASlider.hpp"
+#include "util/audio_backend.hpp"
+namespace waybar::modules {
+
+enum class PulseaudioSliderTarget {
+  Sink,
+  Source,
+};
+
+class PulseaudioSlider : public ASlider {
+ public:
+  PulseaudioSlider(const std::string&, const Json::Value&);
+  virtual ~PulseaudioSlider() = default;
+
+  void update() override;
+  void onValueChanged() override;
+
+ private:
+  std::shared_ptr<util::AudioBackend> backend = nullptr;
+  PulseaudioSliderTarget target = PulseaudioSliderTarget::Sink;
+};
+
+}  // namespace waybar::modules