Flutter BLoC state managment - flutter

Question

I decided to study the architecture of BloC. And something really worries me. I was making a login page and noticed that after calling the Emit () function, the TextField () became empty. If I understand correctly, BlocBuilder has rebuilt the entire widget. Is there a way to rebuild only the part that has changed with a single BlocBuilder? Or something smaller.
UI:
P.S:
there is a function generate Form () It returns
Column (
children: [
TextField (),
TextField (),
],
);
class MainAuth extends StatelessWidget {
#override
Widget build(BuildContext context) {
return CustomScaffold(
resizeToAvoidBottomInset: true,
body: SafeArea(
child: BlocBuilder<AuthBloc, AuthState>(
builder: (context, state) {
if (state is AuthMain) {
return mayBe(
regForm: generateForm(context.read<AuthBloc>().loginForm,
authType.login, context),
loginForm: generateForm(context.read<AuthBloc>().regForm,
authType.register, context),
login: state.type == authType.login,
);
} else {
return Container();
}
},
),
),
);
}
}
class mayBe extends StatelessWidget {
final Widget regForm;
final Widget loginForm;
final bool login;
mayBe({required this.regForm, required this.loginForm, required this.login});
#override
Widget build(BuildContext context) {
return ListenableProvider(
create: (c) {},
child: Column(
children: [
Expanded(
child: SingleChildScrollView(
padding: EdgeInsets.symmetric(horizontal: 16),
child: Column(
children: [
Column(
children: [
ChangedAnimationBlock(
index: login ? 0 : 1,
children: [
Builder(builder: (c) => loginForm),
regForm,
],
),
],
),
],
),
),
),
],
),
);
}
}
Auth Cubit:
import 'package:bloc/bloc.dart';
import 'package:meta/meta.dart';
import 'package:proj/brain/base_functions/forms_to_form.dart';
import 'package:proj/data/repositories/main_api_repository.dart';
part 'auth_state.dart';
class AuthCubit extends Cubit<AuthState> {
final MainApiRepository mainApiRepository;
authType curType = authType.register;
Map responseRegBody = {};
Map responseLoginBody = {};
AuthCubit({required this.mainApiRepository}) : super(AuthInitial()) {
start();
}
Future<void> start() async {
await getForms();
emit(
AuthMain(),
);
}
Future<void> getForms() async {
await getLoginForm();
await getRegisterForm();
}
void changeType() {
var currentState = state;
if (currentState is AuthMain) {
authType oldAuthType = curType;
authType newAuthType;
if (oldAuthType == authType.login) {
newAuthType = authType.register;
} else {
newAuthType = authType.login;
}
// curType = newAuthType;
emit(
AuthMain(type: newAuthType),
);
}
}
Map loginForm = {};
Map regForm = {};
Future<void> getLoginForm() async {
var response = await mainApiRepository.getAuthFromSettings();
loginForm = searchFormIntoForms(response);
print(response);
print(loginForm);
print("loginForm");
}
Future<void> getRegisterForm() async {
var response = await mainApiRepository.getRegistrationFormSettings();
regForm = searchFormIntoForms(response);
}
}
Auth state:
part of 'auth_cubit.dart';
enum authType {
register,
login,
}
#immutable
abstract class AuthState {}
class AuthInitial extends AuthState {}
class AuthMain extends AuthState {
final authType type;
AuthMain({
this.type = authType.register,
});
}