Content menu, content-pack dependencies

src/files/WorldFiles.cpp

@@ -453,13 +453,18 @@ void WorldFiles::write(const World* world, const Content* content) {
 }
 
 void WorldFiles::writePacks(const World* world) {
+    auto packsFile = getPacksFile();
+    if (fs::is_regular_file(packsFile)) {
+        return;
+    }
+
 	const auto& packs = world->getPacks();
 	std::stringstream ss;
 	ss << "# autogenerated; do not modify\n";
 	for (const auto& pack : packs) {
 		ss << pack.id << "\n";
 	}
-	files::write_string(getPacksFile(), ss.str());
+	files::write_string(packsFile, ss.str());
 }
 
 void WorldFiles::writeIndices(const ContentIndices* indices) {
@@ -574,3 +579,15 @@ bool WorldFiles::readPlayer(Player* player) {
     }
 	return true;
 }
+
+void WorldFiles::addPack(const std::string& id) {
+    auto packs = files::read_list(getPacksFile());
+    packs.push_back(id);
+
+	std::stringstream ss;
+	ss << "# autogenerated; do not modify\n";
+	for (const auto& pack : packs) {
+		ss << pack << "\n";
+	}
+	files::write_string(getPacksFile(), ss.str());
+}