Move callback parameter of ui.begin* functions up

See 4f31f85b6b. This is better because the need to pad partial parameter lists with nils is avoided.

src/lua/LuaScriptInterface.cpp

@@ -669,14 +669,37 @@ int LuaScriptInterface::tpt_newIndex(lua_State *l)
 	return 0;
 }
 
+template<class Type>
+struct PickIfTypeHelper;
+
+template<>
+struct PickIfTypeHelper<String>
+{
+	static constexpr auto LuaType = LUA_TSTRING;
+	static String Get(lua_State *l, int index) { return tpt_lua_checkString(l, index); }
+};
+
+template<>
+struct PickIfTypeHelper<bool>
+{
+	static constexpr auto LuaType = LUA_TBOOLEAN;
+	static bool Get(lua_State *l, int index) { return lua_toboolean(l, index); }
+};
+
+template<class Type>
+static Type PickIfType(lua_State *l, int index, Type defaultValue)
+{
+	return lua_type(l, index) == PickIfTypeHelper<Type>::LuaType ? PickIfTypeHelper<Type>::Get(l, index) : defaultValue;
+}
+
 static int beginMessageBox(lua_State* l)
 {
-	String title = tpt_lua_optString(l, 1, "Title");
+	auto title = PickIfType(l, 1, String("Title"));
-	String message = tpt_lua_optString(l, 2, "Message");
+	auto message = PickIfType(l, 2, String("Message"));
-	int large = lua_toboolean(l, 3);
+	auto large = PickIfType(l, 3, false);
 	auto *luacon_ci = static_cast<LuaScriptInterface *>(commandInterface);
 	auto cb = std::make_shared<LuaSmartRef>(luacon_ci->l); // * Bind to main lua state (might be different from l).
-	cb->Assign(l, 4);
+	cb->Assign(l, lua_gettop(l));
 	new InformationMessage(title, message, large, { [cb]() {
 		auto *luacon_ci = static_cast<LuaScriptInterface *>(commandInterface);
 		auto l = luacon_ci->l;
@@ -698,10 +721,10 @@ static int beginMessageBox(lua_State* l)
 
 static int beginThrowError(lua_State* l)
 {
-	String errorMessage = tpt_lua_optString(l, 1, "Error text");
+	auto errorMessage = PickIfType(l, 1, String("Error text"));
 	auto *luacon_ci = static_cast<LuaScriptInterface *>(commandInterface);
 	auto cb = std::make_shared<LuaSmartRef>(luacon_ci->l); // * Bind to main lua state (might be different from l).
-	cb->Assign(l, 2);
+	cb->Assign(l, lua_gettop(l));
 	new ErrorMessage("Error", errorMessage, { [cb]() {
 		auto *luacon_ci = static_cast<LuaScriptInterface *>(commandInterface);
 		auto l = luacon_ci->l;
@@ -723,13 +746,13 @@ static int beginThrowError(lua_State* l)
 
 static int beginInput(lua_State* l)
 {
-	String title = tpt_lua_optString(l, 1, "Title");
+	auto title = PickIfType(l, 1, String("Title"));
-	String prompt = tpt_lua_optString(l, 2, "Enter some text:");
+	auto prompt = PickIfType(l, 2, String("Enter some text:"));
-	String text = tpt_lua_optString(l, 3, "");
+	auto text = PickIfType(l, 3, String(""));
-	String shadow = tpt_lua_optString(l, 4, "");
+	auto shadow = PickIfType(l, 4, String(""));
 	auto *luacon_ci = static_cast<LuaScriptInterface *>(commandInterface);
 	auto cb = std::make_shared<LuaSmartRef>(luacon_ci->l); // * Bind to main lua state (might be different from l).
-	cb->Assign(l, 5);
+	cb->Assign(l, lua_gettop(l));
 	auto handle = [cb](std::optional<String> input) {
 		auto *luacon_ci = static_cast<LuaScriptInterface *>(commandInterface);
 		auto l = luacon_ci->l;
@@ -764,12 +787,12 @@ static int beginInput(lua_State* l)
 
 static int beginConfirm(lua_State *l)
 {
-	String title = tpt_lua_optString(l, 1, "Title");
+	auto title = PickIfType(l, 1, String("Title"));
-	String message = tpt_lua_optString(l, 2, "Message");
+	auto message = PickIfType(l, 2, String("Message"));
-	String buttonText = tpt_lua_optString(l, 3, "Confirm");
+	auto buttonText = PickIfType(l, 3, String("Confirm"));
 	auto *luacon_ci = static_cast<LuaScriptInterface *>(commandInterface);
 	auto cb = std::make_shared<LuaSmartRef>(luacon_ci->l); // * Bind to main lua state (might be different from l).
-	cb->Assign(l, 4);
+	cb->Assign(l, lua_gettop(l));
 	auto handle = [cb](int result) {
 		auto *luacon_ci = static_cast<LuaScriptInterface *>(commandInterface);
 		auto l = luacon_ci->l;
@@ -5083,10 +5106,10 @@ int LuaScriptInterface::luatpt_getscript(lua_State* l)
 
 	int scriptID = luaL_checkinteger(l, 1);
 	auto filename = tpt_lua_checkByteString(l, 2);
-	bool runScript = luaL_optint(l, 3, 0);
+	auto runScript = PickIfType(l, 3, false);
 
 	auto cb = std::make_shared<LuaSmartRef>(luacon_ci->l); // * Bind to main lua state (might be different from l).
-	cb->Assign(l, 4);
+	cb->Assign(l, lua_gettop(l));
 	luacon_ci->scriptDownloadComplete = [cb](const GetScriptStatus &status) {
 		auto *luacon_ci = static_cast<LuaScriptInterface *>(commandInterface);
 		auto l = luacon_ci->l;