fix world previews generation

src/frontend/screens/LevelScreen.cpp

@@ -94,7 +94,11 @@ LevelScreen::LevelScreen(
         renderer->clear();
         return false;
     }));
-
+    controller->preQuitCallbacks.listen([this]() {
+        if (!controller->getLevel()->getWorld()->isNameless()) {
+            saveWorldPreview();
+        }
+    });
     animator = std::make_unique<TextureAnimator>();
     animator->addAnimations(assets.getAnimations());
 
@@ -104,7 +108,6 @@ LevelScreen::LevelScreen(
 LevelScreen::~LevelScreen() {
     if (!controller->getLevel()->getWorld()->isNameless()) {
         saveDecorations();
-        saveWorldPreview();
     }
     scripting::on_frontend_close();
     // unblock all bindings

src/graphics/ui/elements/UINode.hpp

@@ -2,6 +2,7 @@
 
 #include "delegates.hpp"
 #include "graphics/core/commons.hpp"
+#include "util/CallbacksSet.hpp"
 #include "window/input.hpp"
 
 #include <glm/glm.hpp>
@@ -23,29 +24,6 @@ namespace gui {
     using OnNumberChange = std::function<void(GUI&, double)>;
     using OnStringChange = std::function<void(GUI&, const std::string&)>;
 
-    template<typename... Args>
-    class CallbacksSet {
-    public:
-        using Func = std::function<void(Args...)>;
-    private:
-        std::unique_ptr<std::vector<Func>> callbacks;
-    public:
-        void listen(const Func& callback) {
-            if (callbacks == nullptr) {
-                callbacks = std::make_unique<std::vector<Func>>();
-            }
-            callbacks->push_back(callback);
-        }
-
-        void notify(Args&&... args) {
-            if (callbacks) {
-                for (auto& callback : *callbacks) {
-                    callback(std::forward<Args>(args)...);
-                }
-            }
-        }
-    };
-
     template<class TagT, typename... Args>
     class TaggedCallbacksSet {
     public:

src/logic/LevelController.cpp

@@ -122,6 +122,7 @@ void LevelController::update(float delta, bool pause) {
 }
 
 void LevelController::processBeforeQuit() {
+    preQuitCallbacks.notify();
     // todo: move somewhere else
     for (auto player : level->players->getAll()) {
         if (player->chunks) {

src/logic/LevelController.hpp

@@ -5,6 +5,7 @@
 #include "BlocksController.hpp"
 #include "ChunksController.hpp"
 #include "util/Clock.hpp"
+#include "util/CallbacksSet.hpp"
 
 class Engine;
 class Level;
@@ -21,6 +22,8 @@ class LevelController {
 
     util::Clock playerTickClock;
 public:
+    CallbacksSet<> preQuitCallbacks;
+
     LevelController(Engine* engine, std::unique_ptr<Level> level, Player* clientPlayer);
 
     /// @param delta time elapsed since the last update

src/util/CallbacksSet.hpp

@@ -0,0 +1,28 @@
+#pragma once
+
+#include <memory>
+#include <vector>
+#include <functional>
+
+template<typename... Args>
+class CallbacksSet {
+public:
+    using Func = std::function<void(Args...)>;
+private:
+    std::unique_ptr<std::vector<Func>> callbacks;
+public:
+    void listen(const Func& callback) {
+        if (callbacks == nullptr) {
+            callbacks = std::make_unique<std::vector<Func>>();
+        }
+        callbacks->push_back(callback);
+    }
+
+    void notify(Args&&... args) {
+        if (callbacks) {
+            for (auto& callback : *callbacks) {
+                callback(std::forward<Args>(args)...);
+            }
+        }
+    }
+};