refactor: move pulseaudio handling to separate class

include/modules/pulseaudio.hpp

@@ -1,54 +1,27 @@
 #pragma once
 
 #include <fmt/format.h>
-#include <pulse/pulseaudio.h>
-#include <pulse/volume.h>
 
 #include <algorithm>
 #include <array>
+#include <memory>
 
 #include "ALabel.hpp"
+#include "util/audio_backend.hpp"
 
 namespace waybar::modules {
 
 class Pulseaudio : public ALabel {
  public:
   Pulseaudio(const std::string&, const Json::Value&);
-  virtual ~Pulseaudio();
+  virtual ~Pulseaudio() = default;
   auto update() -> void override;
 
  private:
-  static void subscribeCb(pa_context*, pa_subscription_event_type_t, uint32_t, void*);
-  static void contextStateCb(pa_context*, void*);
-  static void sinkInfoCb(pa_context*, const pa_sink_info*, int, void*);
-  static void sourceInfoCb(pa_context*, const pa_source_info* i, int, void* data);
-  static void serverInfoCb(pa_context*, const pa_server_info*, void*);
-  static void volumeModifyCb(pa_context*, int, void*);
-
   bool handleScroll(GdkEventScroll* e) override;
   const std::vector<std::string> getPulseIcon() const;
 
-  pa_threaded_mainloop* mainloop_;
-  pa_mainloop_api* mainloop_api_;
-  pa_context* context_;
-  // SINK
-  uint32_t sink_idx_{0};
-  uint16_t volume_;
-  pa_cvolume pa_volume_;
-  bool muted_;
-  std::string port_name_;
-  std::string form_factor_;
-  std::string desc_;
-  std::string monitor_;
-  std::string current_sink_name_;
-  bool current_sink_running_;
-  // SOURCE
-  uint32_t source_idx_{0};
-  uint16_t source_volume_;
-  bool source_muted_;
-  std::string source_port_name_;
-  std::string source_desc_;
-  std::string default_source_name_;
+  std::shared_ptr<util::AudioBackend> backend = nullptr;
 };
 
 }  // namespace waybar::modules

include/util/audio_backend.hpp

@@ -0,0 +1,90 @@
+#pragma once
+
+#include <json/value.h>
+#include <pulse/context.h>
+#include <pulse/introspect.h>
+#include <pulse/thread-mainloop.h>
+#include <pulse/volume.h>
+
+#include <functional>
+#include <memory>
+#include <string>
+
+namespace waybar::util {
+
+enum class ChangeType : char { Increase, Decrease };
+
+void noop();
+
+class AudioBackend {
+ private:
+  static void subscribeCb(pa_context*, pa_subscription_event_type_t, uint32_t, void*);
+  static void contextStateCb(pa_context*, void*);
+  static void sinkInfoCb(pa_context*, const pa_sink_info*, int, void*);
+  static void sourceInfoCb(pa_context*, const pa_source_info* i, int, void* data);
+  static void serverInfoCb(pa_context*, const pa_server_info*, void*);
+  static void volumeModifyCb(pa_context*, int, void*);
+
+  pa_threaded_mainloop* mainloop_;
+  pa_mainloop_api* mainloop_api_;
+  pa_context* context_;
+  pa_cvolume pa_volume_;
+
+  // SINK
+  uint32_t sink_idx_{0};
+  uint16_t volume_;
+  bool muted_;
+  std::string port_name_;
+  std::string form_factor_;
+  std::string desc_;
+  std::string monitor_;
+  std::string current_sink_name_;
+  bool current_sink_running_;
+  // SOURCE
+  uint32_t source_idx_{0};
+  uint16_t source_volume_;
+  bool source_muted_;
+  std::string source_port_name_;
+  std::string source_desc_;
+  std::string default_source_name_;
+
+  std::vector<std::string> ignored_sinks_;
+
+  std::function<void()> on_updated_cb_ = noop;
+
+  /* Hack to keep constructor inaccessible but still public.
+   * This is required to be able to use std::make_shared.
+   * It is important to keep this class only accessible via a reference-counted
+   * pointer because the destructor will manually free memory, and this could be
+   * a problem with C++20's copy and move semantics.
+   */
+  struct private_constructor_tag {};
+
+ public:
+  static std::shared_ptr<AudioBackend> getInstance(std::function<void()> on_updated_cb = noop);
+
+  AudioBackend(std::function<void()> on_updated_cb, private_constructor_tag tag);
+  ~AudioBackend();
+
+  void changeVolume(ChangeType change_type, double step = 1, int max_volume = 100);
+
+  void setIgnoredSinks(const Json::Value& config);
+
+  std::string getSinkPortName() const { return port_name_; }
+  std::string getFormFactor() const { return form_factor_; }
+  std::string getSinkDesc() const { return desc_; }
+  std::string getMonitor() const { return monitor_; }
+  std::string getCurrentSinkName() const { return current_sink_name_; }
+  bool getCurrentSinkRunning() const { return current_sink_running_; }
+  uint16_t getSinkVolume() const { return volume_; }
+  bool getSinkMuted() const { return muted_; }
+  uint16_t getSourceVolume() const { return source_volume_; }
+  bool getSourceMuted() const { return source_muted_; }
+  std::string getSourcePortName() const { return source_port_name_; }
+  std::string getSourceDesc() const { return source_desc_; }
+  std::string getDefaultSourceName() const { return default_source_name_; }
+
+  bool isBluetooth();
+};
+
+}  // namespace waybar::util