Merge pull request #886 from Alexays/revert-877-jbenden/mpd-module

Revert "mpd: revamped to event-driven, single-threaded"

include/factory.hpp

@@ -37,7 +37,7 @@
 #include "modules/pulseaudio.hpp"
 #endif
 #ifdef HAVE_LIBMPDCLIENT
-#include "modules/mpd/mpd.hpp"
+#include "modules/mpd.hpp"
 #endif
 #ifdef HAVE_LIBSNDIO
 #include "modules/sndio.hpp"

include/modules/mpd.hpp

@@ -0,0 +1,74 @@
+#pragma once
+
+#include <fmt/format.h>
+#include <mpd/client.h>
+#include <condition_variable>
+#include <thread>
+#include "ALabel.hpp"
+
+namespace waybar::modules {
+
+class MPD : public ALabel {
+ public:
+  MPD(const std::string&, const Json::Value&);
+  auto update() -> void;
+
+ private:
+  std::thread periodic_updater();
+  std::string getTag(mpd_tag_type type, unsigned idx = 0);
+  void        setLabel();
+  std::string getStateIcon();
+  std::string getOptionIcon(std::string optionName, bool activated);
+
+  std::thread event_listener();
+
+  // Assumes `connection_lock_` is locked
+  void tryConnect();
+  // If checking errors on the main connection, make sure to lock it using
+  // `connection_lock_` before calling checkErrors
+  void checkErrors(mpd_connection* conn);
+
+  // Assumes `connection_lock_` is locked
+  void fetchState();
+  void waitForEvent();
+
+  bool handlePlayPause(GdkEventButton* const&);
+
+  bool stopped();
+  bool playing();
+  bool paused();
+
+  const std::string module_name_;
+
+  using unique_connection = std::unique_ptr<mpd_connection, decltype(&mpd_connection_free)>;
+  using unique_status = std::unique_ptr<mpd_status, decltype(&mpd_status_free)>;
+  using unique_song = std::unique_ptr<mpd_song, decltype(&mpd_song_free)>;
+
+  // Not using unique_ptr since we don't manage the pointer
+  // (It's either nullptr, or from the config)
+  const char*    server_;
+  const unsigned port_;
+
+  unsigned timeout_;
+
+  // We need a mutex here because we can trigger updates from multiple thread:
+  // the event based updates, the periodic updates needed for the elapsed time,
+  // and the click play/pause feature
+  std::mutex        connection_lock_;
+  unique_connection connection_;
+  // The alternate connection will be used to wait for events: since it will
+  // be blocking (idle) we can't send commands via this connection
+  //
+  // No lock since only used in the event listener thread
+  unique_connection alternate_connection_;
+
+  // Protect them using the `connection_lock_`
+  unique_status status_;
+  mpd_state     state_;
+  unique_song   song_;
+
+  // To make sure the previous periodic_updater stops before creating a new one
+  std::mutex periodic_lock_;
+};
+
+}  // namespace waybar::modules