UI: Reduce IO for texture ini on dev settings.

UI/GameSettingsScreen.cpp

@@ -1826,18 +1826,20 @@ void DeveloperToolsScreen::CreateViews() {
 	list->Add(new Choice(dev->T("Copy savestates to memstick root")))->OnClick.Handle(this, &DeveloperToolsScreen::OnCopyStatesToRoot);
 #endif
 
+	// Reconsider whenever recreating views.
+	hasTexturesIni_ = HasIni::MAYBE;
+
 	Choice *createTextureIni = list->Add(new Choice(dev->T("Create/Open textures.ini file for current game")));
 	createTextureIni->OnClick.Handle(this, &DeveloperToolsScreen::OnOpenTexturesIniFile);
-	createTextureIni->SetEnabledFunc([] {
+	createTextureIni->SetEnabledFunc([&] {
 		if (!PSP_IsInited())
 			return false;
 
 		// Disable the choice to Open/Create if the textures.ini file already exists, and we can't open it due to platform support limitations.
 		if (!System_GetPropertyBool(SYSPROP_SUPPORTS_OPEN_FILE_IN_EDITOR)) {
-			std::string gameID = g_paramSFO.GetDiscID();
-			if (TextureReplacer::IniExists(gameID)) {
-				return false;
-			}
+			if (hasTexturesIni_ == HasIni::MAYBE)
+				hasTexturesIni_ = TextureReplacer::IniExists(g_paramSFO.GetDiscID()) ? HasIni::YES : HasIni::NO;
+			return hasTexturesIni_ != HasIni::YES;
 		}
 		return true;
 	});
@@ -1898,8 +1900,6 @@ UI::EventReturn DeveloperToolsScreen::OnOpenTexturesIniFile(UI::EventParams &e)
 	std::string gameID = g_paramSFO.GetDiscID();
 	Path generatedFilename;
 
-	bool existedBefore = TextureReplacer::IniExists(gameID);
-
 	if (TextureReplacer::GenerateIni(gameID, generatedFilename)) {
 		if (System_GetPropertyBool(SYSPROP_SUPPORTS_OPEN_FILE_IN_EDITOR)) {
 			File::OpenFileInEditor(generatedFilename);
@@ -1908,6 +1908,8 @@ UI::EventReturn DeveloperToolsScreen::OnOpenTexturesIniFile(UI::EventParams &e)
 			auto dev = GetI18NCategory("Developer");
 			System_Toast((generatedFilename.ToVisualString() + ": " +  dev->T("Texture ini file created")).c_str());
 		}
+
+		hasTexturesIni_ = HasIni::YES;
 	}
 	return UI::EVENT_DONE;
 }

UI/GameSettingsScreen.h

@@ -181,6 +181,12 @@ private:
 
 	bool allowDebugger_ = false;
 	bool canAllowDebugger_ = true;
+	enum class HasIni {
+		NO,
+		YES,
+		MAYBE,
+	};
+	HasIni hasTexturesIni_ = HasIni::MAYBE;
 };
 
 class HostnameSelectScreen : public PopupScreen {