Initial implementation

include/util/pipewire/pipewire_backend.hpp

@@ -0,0 +1,40 @@
+#pragma once
+
+#include <pipewire/pipewire.h>
+
+#include "util/backend_common.hpp"
+#include "util/pipewire/privacy_node_info.hpp"
+
+namespace waybar::util::PipewireBackend {
+
+class PipewireBackend {
+ private:
+  pw_thread_loop* mainloop_;
+  pw_context* context_;
+  pw_core* core_;
+
+  spa_hook registry_listener;
+
+  /* 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:
+  std::mutex mutex_;
+
+  pw_registry* registry;
+
+  sigc::signal<void> privacy_nodes_changed_signal_event;
+
+  std::unordered_map<uint32_t, PrivacyNodeInfo*> privacy_nodes;
+
+  static std::shared_ptr<PipewireBackend> getInstance();
+
+  PipewireBackend(private_constructor_tag tag);
+  ~PipewireBackend();
+};
+}  // namespace waybar::util::pipewire::PipewireBackend

include/util/pipewire/privacy_node_info.hpp

@@ -0,0 +1,36 @@
+#pragma once
+
+#include <pipewire/pipewire.h>
+
+#include <string>
+
+namespace waybar::util::PipewireBackend {
+
+enum PrivacyNodeType {
+  PRIVACY_NODE_TYPE_NONE,
+  PRIVACY_NODE_TYPE_VIDEO_INPUT,
+  PRIVACY_NODE_TYPE_AUDIO_INPUT,
+  PRIVACY_NODE_TYPE_AUDIO_OUTPUT
+};
+
+class PrivacyNodeInfo {
+ public:
+  PrivacyNodeType type = PRIVACY_NODE_TYPE_NONE;
+  uint32_t id;
+  uint32_t client_id;
+  enum pw_node_state state = PW_NODE_STATE_IDLE;
+  std::string media_class;
+  std::string media_name;
+  std::string node_name;
+
+  struct spa_hook node_listener;
+
+  bool changed = false;
+
+  void* data;
+
+  PrivacyNodeInfo(uint32_t id_, void* data_) : id(id_), data(data_) {}
+
+  ~PrivacyNodeInfo() { spa_hook_remove(&node_listener); }
+};
+}  // namespace waybar::util::pipewire::PipewireBackend