Waybar/include/util/audio_backend.hpp

#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(uint16_t volume, uint16_t min_volume = 0, uint16_t max_volume = 100);
  void changeVolume(ChangeType change_type, double step = 1, uint16_t 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