Store last loaded playlist

doc/protocol.rst

@@ -544,6 +544,7 @@ Querying :program:`MPD`'s status
       :ref:`audio_output_format` for a detailed explanation.
     - ``updating_db``: ``job id``
     - ``error``: if there is an error, returns message here
+    - ``lastloadedplaylist``: last loaded stored playlist [#since_0_24]_
 
     :program:`MPD` may omit lines which have no (known) value.  Older
     :program:`MPD` versions used to have a "magic" value for

src/command/PlayerCommands.cxx

@@ -44,6 +44,7 @@
 #define COMMAND_STATUS_MIXRAMPDELAY	"mixrampdelay"
 #define COMMAND_STATUS_AUDIO		"audio"
 #define COMMAND_STATUS_UPDATING_DB	"updating_db"
+#define COMMAND_STATUS_LOADED_PLAYLIST  "lastloadedplaylist"
 
 CommandResult
 handle_play(Client &client, Request args, [[maybe_unused]] Response &r)
@@ -128,7 +129,8 @@ handle_status(Client &client, [[maybe_unused]] Request args, Response &r)
 			 COMMAND_STATUS_PLAYLIST ": {}\n"
 			 COMMAND_STATUS_PLAYLIST_LENGTH ": {}\n"
 			 COMMAND_STATUS_MIXRAMPDB ": {}\n"
-			 COMMAND_STATUS_STATE ": {}\n"),
+			 COMMAND_STATUS_STATE ": {}\n"
+			 COMMAND_STATUS_LOADED_PLAYLIST ": {}\n"),
 	      (unsigned)playlist.GetRepeat(),
 	      (unsigned)playlist.GetRandom(),
 	      SingleToString(playlist.GetSingle()),
@@ -137,7 +139,8 @@ handle_status(Client &client, [[maybe_unused]] Request args, Response &r)
 	      playlist.GetVersion(),
 	      playlist.GetLength(),
 	      pc.GetMixRampDb(),
-	      state);
+	      state,
+	      playlist.GetLastLoadedPlaylist());
 
 	if (pc.GetCrossFade() > FloatDuration::zero())
 		r.Fmt(FMT_STRING(COMMAND_STATUS_CROSSFADE ": {}\n"),

src/playlist/PlaylistQueue.cxx

@@ -55,6 +55,7 @@ playlist_load_into_queue(const char *uri, SongEnumerator &e,
 
 		dest.AppendSong(pc, std::move(*song));
 	}
+	dest.SetLastLoadedPlaylist(uri);
 }
 
 void

src/queue/Playlist.hxx

@@ -102,6 +102,14 @@ struct playlist {
 	[[gnu::pure]]
 	int GetNextPosition() const noexcept;
 
+	const std::string_view GetLastLoadedPlaylist() const noexcept {
+		return queue.last_loaded_playlist;
+	}
+
+	void SetLastLoadedPlaylist(const char *playlist_name) noexcept {
+		queue.last_loaded_playlist = playlist_name;
+	}
+
 	/**
 	 * Returns the song object which is currently queued.  Returns
 	 * none if there is none (yet?) or if MPD isn't playing.

src/queue/PlaylistState.cxx

@@ -36,6 +36,7 @@
 #define PLAYLIST_STATE_FILE_CROSSFADE		"crossfade: "
 #define PLAYLIST_STATE_FILE_MIXRAMPDB		"mixrampdb: "
 #define PLAYLIST_STATE_FILE_MIXRAMPDELAY	"mixrampdelay: "
+#define PLAYLIST_STATE_FILE_LOADED_PLAYLIST	"lastloadedplaylist: "
 #define PLAYLIST_STATE_FILE_PLAYLIST_BEGIN	"playlist_begin"
 #define PLAYLIST_STATE_FILE_PLAYLIST_END	"playlist_end"
 
@@ -85,6 +86,8 @@ playlist_state_save(BufferedOutputStream &os, const struct playlist &playlist,
 	       pc.GetMixRampDb());
 	os.Fmt(FMT_STRING(PLAYLIST_STATE_FILE_MIXRAMPDELAY "{}\n"),
 	       pc.GetMixRampDelay().count());
+	os.Fmt(FMT_STRING(PLAYLIST_STATE_FILE_LOADED_PLAYLIST "{}\n"),
+	       playlist.GetLastLoadedPlaylist());
 	os.Write(PLAYLIST_STATE_FILE_PLAYLIST_BEGIN "\n");
 	queue_save(os, playlist.queue);
 	os.Write(PLAYLIST_STATE_FILE_PLAYLIST_END "\n");
@@ -156,6 +159,8 @@ playlist_state_restore(const StateFileConfig &config,
 			   prior to MPD 0.18 */
 			if (IsDigitASCII(*p))
 				pc.SetMixRampDelay(FloatDuration(ParseFloat(p)));
+		} else if ((p = StringAfterPrefix(line, PLAYLIST_STATE_FILE_LOADED_PLAYLIST))) {
+			playlist.SetLastLoadedPlaylist(p);
 		} else if ((p = StringAfterPrefix(line, PLAYLIST_STATE_FILE_RANDOM))) {
 			random_mode = StringIsEqual(p, "1");
 		} else if ((p = StringAfterPrefix(line, PLAYLIST_STATE_FILE_CURRENT))) {

src/queue/Queue.cxx

@@ -270,6 +270,7 @@ Queue::Clear() noexcept
 	}
 
 	length = 0;
+	last_loaded_playlist.clear();
 }
 
 static void

src/queue/Queue.hxx

@@ -85,6 +85,9 @@ struct Queue {
 	/** play back songs in random order? */
 	bool random = false;
 
+	/** Last loaded playlist */
+	std::string last_loaded_playlist;
+
 	/** random number generator for shuffle and random mode */
 	LazyRandomEngine rand;