db/upnp/Object: use strictly-typed enums

At the same time, rename the enum types and the class attributes, and
add an "UNKNOWN" type/class.  The latter avoids the "-1" hack.

src/db/UpnpDatabasePlugin.cxx

@@ -721,18 +721,27 @@ UpnpDatabase::VisitServer(ContentDirectoryService* server,
 		return SearchSongs(server, objid.c_str(), selection,
 				   visit_song, error);
 
-	if (tdirent.m_type == UPnPDirObject::item) {
+	if (tdirent.type == UPnPDirObject::Type::ITEM) {
 		// Target is a song. Not too sure we ever get there actually, maybe
 		// this is always catched by the special uri test above.
-		if (visit_song &&
-		    tdirent.m_iclass == UPnPDirObject::audioItem_musicTrack) {
-			return visitSong(tdirent, "", selection, visit_song,
-					 error);
-		} else if (visit_playlist &&
-			   tdirent.m_iclass == UPnPDirObject::audioItem_playlist) {
-			// Note: I've yet to see a playlist item (playlists
-			// seem to be usually handled as containers, so I'll
-			// decide what to do when I see one...
+		switch (tdirent.item_class) {
+		case UPnPDirObject::ItemClass::MUSIC:
+			if (visit_song)
+				return visitSong(tdirent, "", selection, visit_song,
+						 error);
+			break;
+
+		case UPnPDirObject::ItemClass::PLAYLIST:
+			if (visit_playlist) {
+				/* Note: I've yet to see a playlist
+				 item (playlists seem to be usually
+				 handled as containers, so I'll decide
+				 what to do when I see one... */
+			}
+			break;
+
+		case UPnPDirObject::ItemClass::UNKNOWN:
+			break;
 		}
 
 		return true;
@@ -757,28 +766,40 @@ UpnpDatabase::VisitServer(ContentDirectoryService* server,
 
 	if (visit_song || visit_playlist) {
 		for (const auto &dirent : dirbuf.m_items) {
-			if (visit_song &&
-			    dirent.m_iclass == UPnPDirObject::audioItem_musicTrack) {
-				/* We identify songs by giving them a
-				   special path. The Id is enough to
-				   fetch them from the server
-				   anyway. */
+			switch (dirent.item_class) {
+			case UPnPDirObject::ItemClass::MUSIC:
+				if (visit_song) {
+					/* We identify songs by giving
+					   them a special path. The Id
+					   is enough to fetch them
+					   from the server anyway. */
 
-				std::string p;
-				if (!selection.recursive)
-					p = selection.uri + "/" +
-						titleToPathElt(dirent.m_title);
+					std::string p;
+					if (!selection.recursive)
+						p = selection.uri + "/" +
+							titleToPathElt(dirent.m_title);
 
-				if (!visitSong(dirent, p.c_str(),
-					       selection, visit_song, error))
-					return false;
-			} else if (visit_playlist &&
-				   dirent.m_iclass == UPnPDirObject::audioItem_playlist) {
-				/* Note: I've yet to see a playlist
-				   item (playlists seem to be usually
-				   handled as containers, so I'll
-				   decide what to do when I see
-				   one... */
+					if (!visitSong(dirent, p.c_str(),
+						       selection, visit_song, error))
+						return false;
+				}
+
+				break;
+
+			case UPnPDirObject::ItemClass::PLAYLIST:
+				if (visit_playlist) {
+					/* Note: I've yet to see a
+					   playlist item (playlists
+					   seem to be usually handled
+					   as containers, so I'll
+					   decide what to do when I
+					   see one... */
+				}
+
+				break;
+
+			case UPnPDirObject::ItemClass::UNKNOWN:
+				break;
 			}
 		}
 	}

src/db/upnp/Directory.cxx

@@ -56,9 +56,9 @@ public:
 		:m_dir(dir)
 	{
 		m_okitems["object.item.audioItem.musicTrack"] =
-			UPnPDirObject::audioItem_musicTrack;
+			UPnPDirObject::ItemClass::MUSIC;
 		m_okitems["object.item.playlistItem"] =
-			UPnPDirObject::audioItem_playlist;
+			UPnPDirObject::ItemClass::PLAYLIST;
 	}
 	UPnPDirContent& m_dir;
 
@@ -74,7 +74,7 @@ protected:
 		case 'c':
 			if (!strcmp(name, "container")) {
 				m_tobj.clear();
-				m_tobj.m_type = UPnPDirObject::container;
+				m_tobj.type = UPnPDirObject::Type::CONTAINER;
 				m_tobj.m_id = m_path.back().attributes["id"];
 				m_tobj.m_pid = m_path.back().attributes["parentID"];
 			}
@@ -82,7 +82,7 @@ protected:
 		case 'i':
 			if (!strcmp(name, "item")) {
 				m_tobj.clear();
-				m_tobj.m_type = UPnPDirObject::item;
+				m_tobj.type = UPnPDirObject::Type::ITEM;
 				m_tobj.m_id = m_path.back().attributes["id"];
 				m_tobj.m_pid = m_path.back().attributes["parentID"];
 			}
@@ -96,14 +96,14 @@ protected:
 		bool ok =  !m_tobj.m_id.empty() && !m_tobj.m_pid.empty() &&
 			!m_tobj.m_title.empty();
 
-		if (ok && m_tobj.m_type == UPnPDirObject::item) {
+		if (ok && m_tobj.type == UPnPDirObject::Type::ITEM) {
 			auto it = m_okitems.find(m_tobj.m_props["upnp:class"]);
 			if (it == m_okitems.end()) {
 				PLOGINF("checkobjok: found object of unknown class: [%s]\n",
 					m_tobj.m_props["upnp:class"].c_str());
 				ok = false;
 			} else {
-				m_tobj.m_iclass = it->second;
+				m_tobj.item_class = it->second;
 			}
 		}
 

src/db/upnp/Object.hxx

@@ -30,7 +30,12 @@
  */
 class UPnPDirObject {
 public:
-	enum ObjType {item, container};
+	enum class Type {
+		UNKNOWN,
+		ITEM,
+		CONTAINER,
+	};
+
 	// There are actually several kinds of containers:
 	// object.container.storageFolder, object.container.person,
 	// object.container.playlistContainer etc., but they all seem to
@@ -38,13 +43,17 @@ public:
 	// items are special to us, and so should playlists, but I've not
 	// seen one of the latter yet (servers seem to use containers for
 	// playlists).
-	enum ItemClass {audioItem_musicTrack, audioItem_playlist};
+	enum class ItemClass {
+		UNKNOWN,
+		MUSIC,
+		PLAYLIST,
+	};
 
 	std::string m_id; // ObjectId
 	std::string m_pid; // Parent ObjectId
 	std::string m_title; // dc:title. Directory name for a container.
-	ObjType m_type; // item or container
-	ItemClass m_iclass;
+	Type type;
+	ItemClass item_class;
 	// Properties as gathered from the XML document (url, artist, etc.)
 	// The map keys are the XML tag or attribute names.
 	std::map<std::string, std::string> m_props;
@@ -68,8 +77,8 @@ public:
 		m_id.clear();
 		m_pid.clear();
 		m_title.clear();
-		m_type = (ObjType)-1;
-		m_iclass = (ItemClass)-1;
+		type = Type::UNKNOWN;
+		item_class = ItemClass::UNKNOWN;
 		m_props.clear();
 	}
 };