Working on loading screen

src/MenuManager.cpp

@@ -8,6 +8,7 @@
 #include <fstream>
 #include <algorithm>
 #include <string>
+#include <SDL.h>
 
 namespace ZL {
 
@@ -119,6 +120,9 @@ namespace ZL {
 	}
 
 	std::shared_ptr<UiNode> MenuManager::loadLocalizedUi(const std::string& basePath, const std::string& zipFile) {
+		// Service the OS message queue between UI screens so the window doesn't
+		// get flagged as "not responding" while loading the ~50 UI layout files.
+		SDL_PumpEvents();
 		static const std::string marker = "resources/w/ui/";
 		if (basePath.rfind(marker, 0) == 0) {
 			const std::string localizedPath = "resources/w/ui_" + languageToCode(g_currentLanguage) + "/" + basePath.substr(marker.size());
@@ -507,9 +511,6 @@ namespace ZL {
 	}
 
 	void MenuManager::reloadLocalizedGameContent() {
-		ItemRegistry::instance().loadFromJson("resources/config/items.json", CONST_ZIP_FILE);
-		gameState_.questJournal.reloadDefinitionsPreservingState("resources/config/quests.json", CONST_ZIP_FILE);
-
 		// Screens below the Language screen on the menu stack hold onto their old
 		// (pre-reload) UiNode instances, so simply reopening Language on top of
 		// them would leave Main Menu / Settings / the pause menu showing stale
@@ -525,16 +526,37 @@ namespace ZL {
 			for (int i = 0; i < depth; ++i) uiManager.popMenu();
 		}
 
-		loadUiRoots(CONST_ZIP_FILE);
+		// Unloading/reloading ~50 UI screens and their textures is heavy enough to
+		// freeze the window for a noticeable moment, so run it the same way the
+		// initial resource load runs: a queue of closures drained one per frame
+		// with the loading screen shown, instead of one big blocking call here.
+		std::vector<std::function<void()>> steps;
 
-		toastTextureQuestNew = loadLocalizedTexture("resources/w/ui/img/toast/quest_new001.png", CONST_ZIP_FILE);
-		toastTextureQuestCompleted = loadLocalizedTexture("resources/w/ui/img/toast/quest_completed001.png", CONST_ZIP_FILE);
-		toastTextureQuestFailed = loadLocalizedTexture("resources/w/ui/img/toast/quest_failed001.png", CONST_ZIP_FILE);
-		toastTextureItemAdded = loadLocalizedTexture("resources/w/ui/img/toast/item_received001.png", CONST_ZIP_FILE);
-		toastTextureItemRemoved = loadLocalizedTexture("resources/w/ui/img/toast/item_removed001.png", CONST_ZIP_FILE);
+		steps.push_back([this]() {
+			ItemRegistry::instance().loadFromJson("resources/config/items.json", CONST_ZIP_FILE);
+			gameState_.questJournal.reloadDefinitionsPreservingState("resources/config/quests.json", CONST_ZIP_FILE);
+		});
 
+		steps.push_back([this]() {
+			renderer.textureManager.UnloadByPrefix("resources/w/ui");
+			loadUiRoots(CONST_ZIP_FILE);
 
-		showMainMenu();
+			toastTextureQuestNew = loadLocalizedTexture("resources/w/ui/img/toast/quest_new001.png", CONST_ZIP_FILE);
+			toastTextureQuestCompleted = loadLocalizedTexture("resources/w/ui/img/toast/quest_completed001.png", CONST_ZIP_FILE);
+			toastTextureQuestFailed = loadLocalizedTexture("resources/w/ui/img/toast/quest_failed001.png", CONST_ZIP_FILE);
+			toastTextureItemAdded = loadLocalizedTexture("resources/w/ui/img/toast/item_received001.png", CONST_ZIP_FILE);
+			toastTextureItemRemoved = loadLocalizedTexture("resources/w/ui/img/toast/item_removed001.png", CONST_ZIP_FILE);
+		});
+
+		steps.push_back([this]() {
+			showMainMenu();
+		});
+
+		if (runAsLoadingSequence) {
+			runAsLoadingSequence(std::move(steps));
+		} else {
+			for (auto& step : steps) step();
+		}
 	}
 
 	void MenuManager::showLoadGameScreen()