Change notification mechanisms for assets

include/openspace/scene/asset.h

@@ -120,6 +120,16 @@ public:
 
     std::string resolveLocalResource(std::string resourceName);
 private:
+    void requiredAssetChangedState(std::shared_ptr<Asset> a);
+    void requestedAssetChangedState(std::shared_ptr<Asset> a);
+
+    void addRequestingAsset(std::shared_ptr<Asset> a);
+    void removeRequestingAsset(std::shared_ptr<Asset> a);
+    void addRequiringAsset(std::shared_ptr<Asset> a);
+    void removeRequiringAsset(std::shared_ptr<Asset> a);
+
+    bool isSyncResolveReady();
+
     std::atomic<State> _state;
     AssetLoader* _loader;
     std::vector<std::shared_ptr<ResourceSynchronization>> _synchronizations;

include/openspace/scene/assetloader.h

@@ -58,10 +58,7 @@ int exportAsset(lua_State* state);
 } // namespace assetloader
 
 class AssetLoader {
-public:
-    using CallbackHandle = size_t;
-    using AssetLoadCallback = std::function<void(std::shared_ptr<Asset>)>;
-    
+public:  
     /**
      * Constructor
      */
@@ -131,9 +128,6 @@ public:
     std::string generateAssetPath(const std::string& baseDirectory,
                                   const std::string& path) const;
     
-    CallbackHandle addAssetLoadCallback(AssetLoadCallback);
-    void removeAssetLoadCallback(CallbackHandle cbh);
-
 private:
     std::shared_ptr<Asset> require(const std::string& identifier);
     std::shared_ptr<Asset> request(const std::string& path);
@@ -186,10 +180,6 @@ private:
         _onDependencyDeinitializationFunctionRefs;
 
     int _assetsTableRef;
-    
-    std::unordered_map<CallbackHandle, AssetLoadCallback> _assetLoadCallbacks;
-    CallbackHandle _nextCallbackId;
-
 };
 
 

include/openspace/scene/assetmanager.h

@@ -76,7 +76,6 @@ private:
     std::vector<std::shared_ptr<Asset>> _pendingInitializations;
 
     std::unique_ptr<AssetLoader> _assetLoader;
-    AssetLoader::CallbackHandle _addAssetCallbackHandle;
 };
 
 } // namespace openspace