feat(MPRIS): default to currently-playing client on startup (#87)

fix: #19
Reviewed-on: https://codeberg.org/GeopJr/Turntable/pulls/87

Author: GeopJr

src/Mpris/Entry.vala

@@ -318,4 +318,17 @@ public class Turntable.Mpris.Entry : GLib.Object {
 			this.notify_property ("length");
 		}
 	}
+
+	public async bool is_active () {
+		try {
+			DesktopBus.Mpris.MediaPlayer2Player bus = yield Bus.get_proxy (
+				BusType.SESSION,
+				this.bus_namespace,
+				"/org/mpris/MediaPlayer2"
+			);
+			return bus.playback_status == "Playing";
+		} catch {
+			return false;
+		}
+	}
 }

src/Mpris/Manager.vala

@@ -60,4 +60,15 @@ public class Turntable.Mpris.Manager : GLib.Object {
 			remove_player (name);
 		}
 	}
+
+	public async Entry? active_player () {
+		for (int i = 0; i < entries.length ; i++) {
+			var entry = entries.index (i);
+			if (yield entry.is_active ()) {
+				return entry;
+			}
+		}
+
+		return null;
+	}
 }

src/Widgets/ControlsOverlay.vala

@@ -333,11 +333,27 @@ public class Turntable.Widgets.ControlsOverlay : Adw.Bin {
 		toggle_controls ();
 	}
 
+	private bool done_initial_active_check = false;
 	private void update_store () {
 		players_store.splice (0, players_store.n_items, mpris_manager.get_players ());
 		players_store.sort ((GLib.CompareDataFunc<Mpris.Entry>) compare_players);
-
 		client_dropdown.enable_search = players_store.n_items > 10;
+
+		if (!done_initial_active_check) {
+			done_initial_active_check = true;
+			if (players_store.n_items > 1) {
+				mpris_manager.active_player.begin ((obj, res) => {
+					Mpris.Entry? active_player = mpris_manager.active_player.end (res);
+					if (active_player != null) {
+						uint pos;
+						if (players_store.find (active_player, out pos)) {
+							client_dropdown.selected = pos;
+						}
+					}
+				});
+			}
+		}
+
 		if (this.last_player == null) selection_changed (); // if always ensure player
 	}