Expose playlists in the menu if the player exports them

2 files changed, 110 insertions, 3 deletions

diff --git a/src/media-player.vala b/src/media-player.vala
index 9c18f10..7326708 100644
--- a/src/media-player.vala
+++ b/src/media-player.vala
@@ -84,6 +84,8 @@ public class MediaPlayer: Object {
 		get; set;
 	}
 
+	public signal void playlists_changed ();
+
 	/**
 	 * Attach this object to a process of the associated media player.  The player must own @dbus_name and
 	 * implement the org.mpris.MediaPlayer2.Player interface.
@@ -98,6 +100,8 @@ public class MediaPlayer: Object {
 		this._dbus_name = dbus_name;
 		Bus.get_proxy.begin<MprisPlayer> (BusType.SESSION, dbus_name, "/org/mpris/MediaPlayer2",
 										  DBusProxyFlags.GET_INVALIDATED_PROPERTIES, null, got_proxy);
+		Bus.get_proxy.begin<MprisPlaylists> (BusType.SESSION, dbus_name, "/org/mpris/MediaPlayer2",
+											 DBusProxyFlags.GET_INVALIDATED_PROPERTIES, null, got_playlists_proxy);
 	}
 
 	/**
@@ -160,10 +164,31 @@ public class MediaPlayer: Object {
 			this.proxy.Previous.begin ();
 	}
 
+	public uint get_n_playlists () {
+		return this.playlists != null ? this.playlists.length : 0;
+	}
+
+	public string get_playlist_id (int index) {
+		return_val_if_fail (index < this.playlists.length, "");
+		return this.playlists[index].path;
+	}
+
+	public string get_playlist_name (int index) {
+		return_val_if_fail (index < this.playlists.length, "");
+		return this.playlists[index].name;
+	}
+
+	public void activate_playlist_by_name (string name) {
+		if (this.playlists_proxy != null)
+			this.playlists_proxy.ActivatePlaylist.begin (new ObjectPath (name));
+	}
+
 	DesktopAppInfo appinfo;
 	MprisPlayer? proxy;
+	MprisPlaylists ?playlists_proxy;
 	string _dbus_name;
 	bool play_when_attached = false;
+	PlaylistDetails[] playlists = null;
 
 	void got_proxy (Object? obj, AsyncResult res) {
 		try {
@@ -191,6 +216,42 @@ public class MediaPlayer: Object {
 		}
 	}
 
+	void fetch_playlists () {
+		/* The proxy is created even when the interface is not supported. GDBusProxy will
+		   return 0 for the PlaylistCount property in that case. */
+		if (this.playlists_proxy != null && this.playlists_proxy.PlaylistCount > 0) {
+			this.playlists_proxy.GetPlaylists.begin (0, 100, "Alphabetical", false, (obj, res) => {
+				try {
+					this.playlists = playlists_proxy.GetPlaylists.end (res);
+					this.playlists_changed ();
+				}
+				catch (Error e) {
+					warning ("could not fetch playlists: %s", e.message);
+					this.playlists = null;
+				}
+			});
+		}
+		else {
+			this.playlists = null;
+			this.playlists_changed ();
+		}
+	}
+
+	void got_playlists_proxy (Object? obj, AsyncResult res) {
+		try {
+			this.playlists_proxy = Bus.get_proxy.end (res);
+
+			var gproxy = this.proxy as DBusProxy;
+			gproxy.g_properties_changed.connect (this.playlists_proxy_properties_changed);
+		}
+		catch (Error e) {
+			warning ("unable to create mpris plalists proxy: %s", e.message);
+			return;
+		}
+
+		Timeout.add (500, () => { this.fetch_playlists (); return false; } );
+	}
+
 	/* some players (e.g. Spotify) don't follow the spec closely and pass single strings in metadata fields
 	 * where an array of string is expected */
 	static string sanitize_metadata_value (Variant? v) {
@@ -215,6 +276,11 @@ public class MediaPlayer: Object {
 			this.update_current_track (metadata);
 	}
 
+	void playlists_proxy_properties_changed (DBusProxy proxy, Variant changed_properties, string[] invalidated_properties) {
+		if (changed_properties.lookup ("PlaylistCount", "u", null))
+			this.fetch_playlists ();
+	}
+
 	void update_current_track (Variant metadata) {
 		if (metadata != null) {
 			this.current_track = new Track (
diff --git a/src/service.vala b/src/service.vala
index 7f89c66..6a330f2 100644
--- a/src/service.vala
+++ b/src/service.vala
@@ -266,6 +266,37 @@ public class IndicatorSound.Service {
 		this.settings.set_value ("preferred-media-players", builder.end ());
 	}
 
+	void update_playlists (MediaPlayer player) {
+		int index = find_player_section (player);
+		if (index < 0)
+			return;
+
+		var section = this.menu.get_item_link (index, Menu.LINK_SECTION) as Menu;
+
+		/* if a section has three items, the playlists menu is in it */
+		if (section.get_n_items () == 3)
+			section.remove (2);
+
+		if (!player.is_running)
+			return;
+
+		var count = player.get_n_playlists ();
+		if (count == 0)
+			return;
+
+		var playlists_section = new Menu ();
+		for (int i = 0; i < count; i++) {
+			var playlist_id = player.get_playlist_id (i);
+			playlists_section.append (player.get_playlist_name (i),
+									  @"indicator.play-playlist.$(player.id)::$playlist_id");
+								   
+		}
+
+		var submenu = new Menu ();
+		submenu.append_section (null, playlists_section);
+		section.append_submenu ("Choose Playlist", submenu);
+	}
+
 	void player_added (MediaPlayer player) {
 		var player_item = new MenuItem (player.name, "indicator." + player.id);
 		player_item.set_attribute ("x-canonical-type", "s", "com.canonical.unity.media-player");
@@ -303,19 +334,28 @@ public class IndicatorSound.Service {
 		prev_action.activate.connect ( () => player.previous () );
 		this.actions.insert (prev_action);
 
+		var playlist_action = new SimpleAction ("play-playlist." + player.id, VariantType.STRING);
+		playlist_action.activate.connect ( (parameter) => player.activate_playlist_by_name (parameter.get_string ()) );
+		this.actions.insert (playlist_action);
+
 		player.notify.connect (this.eventually_update_player_actions);
 
+		player.playlists_changed.connect (this.update_playlists);
+		player.notify["is-running"].connect ( () => this.update_playlists (player) );
+		update_playlists (player);
+
 		this.update_preferred_players ();
 	}
 
 	/* returns the position in this.menu of the section that's associated with @player */
 	int find_player_section (MediaPlayer player) {
-		int n = this.menu.get_n_items ();
-		for (int i = 0; i < n; i++) {
+		string action_name = @"indicator.$(player.id)";
+		int n = this.menu.get_n_items () -1;
+		for (int i = 1; i < n; i++) {
 			var section = this.menu.get_item_link (i, Menu.LINK_SECTION);
 			string action;
 			section.get_item_attribute (0, "action", "s", out action);
-			if (action == player.id)
+			if (action == action_name)
 				return i;
 		}
 
@@ -327,6 +367,7 @@ public class IndicatorSound.Service {
 		this.actions.remove ("play." + player.id);
 		this.actions.remove ("next." + player.id);
 		this.actions.remove ("previous." + player.id);
+		this.actions.remove ("play-playlist." + player.id);
 
 		int index = this.find_player_section (player);
 		if (index >= 0)