Stack widget and Bloc Builder - flutter

Question

I know Stack Widgets render their children from the ground up, however, I couldn't explain to myself why a BlocBuilder cannot efficiently rebuild them.
Here is an example:
#override
Widget build(BuildContext context) {
return Container(
child: BlocBuilder<TestCubit, int>(
builder: (context, state) {
return GestureDetector(
onTapDown: (tapDetails) {
context.read<TestCubit>().incrementCubit();
},
child: Stack(children: [Text('Counter: $state')]),
);
},
)
);
}
When TestCubit has its incrementCubit method called, the state changes - I tested it with a simple Container based UI, but once we are dealing with a Stack, nothing happens on the screen. Any ideas?
Thanks in advance!

Answer 1

I tested your code and it works with both Stack as well as Container. Please see my code below :
main.dart
import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
void main() {
runApp(
const CounterApp(),
);
}
class CounterApp extends MaterialApp {
const CounterApp({Key key}) : super(key: key, home: const CounterPage());
}
class CounterPage extends StatelessWidget {
const CounterPage({Key key}) : super(key: key);
#override
Widget build(BuildContext context) {
return BlocProvider(
create: (_) => TestCubit(),
child: CounterView(),
);
}
}
class CounterView extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Container(child: BlocBuilder<TestCubit, int>(
builder: (context, state) {
return GestureDetector(
onTapDown: (tapDetails) {
context.read<TestCubit>().incrementCubit();
},
child: Stack(children: [Text('Counter: $state')]),
//child: Text('Counter: $state'),
//child: Scaffold(
// appBar: AppBar(title: const Text("Cubit Demo")),
// body: Center(
// child: Stack(
// children: [
// Text('Counter: $state'),
// ],
// )),
//),
);
},
));
}
}
class TestCubit extends Cubit<int> {
TestCubit() : super(0);
void incrementCubit() => emit(state + 1);
void decrementCubit() => emit(state - 1);
}
pubspec.yaml
name: test_http
description: A new Flutter application.
publish_to: 'none'
version: 1.0.0+1
environment:
sdk: ">=2.7.0 <3.0.0"
dependencies:
flutter:
sdk: flutter
flutter_bloc:
dev_dependencies:
flutter_test:
sdk: flutter
flutter:
uses-material-design: true