add background assets loader

src/engine/AssetsManagement.hpp

@@ -1,22 +1,31 @@
 #pragma once
 
+#include "assets/Assets.hpp"
+
 #include <memory>
 
-class Assets;
 class AssetsLoader;
 class Engine;
 class Content;
+class Task;
 
-class AssetsManagement {
+class AssetsManagement final {
 public:
     AssetsManagement(Engine& engine);
+    ~AssetsManagement();
 
     void loadAssets(Content* content);
+    void update();
     
     Assets* getStorage();
     const Assets* getStorage() const;
+
+    AssetsLoader& acquireBackgroundLoader();
 private:
+    void finishBackgroundLoader();
+
     Engine& engine;
     std::unique_ptr<Assets> assets;
     std::unique_ptr<AssetsLoader> backgroundLoader;
+    std::shared_ptr<Task> backgroundLoaderTask;
 };