unnecessary container but I need this container? flutter/Dart - flutter

Question

I am working on a app were I get data from the ESP32 and display it on a simple page. Here is my code for my sensorpage:
import 'dart:async';
import 'dart:convert' show utf8;
import 'package:flutter/material.dart';
import 'package:flutter_blue/flutter_blue.dart';
class sensorpage extends StatefulWidget {
const sensorpage({Key? key, required this.device}) : super(key: key);
final BluetoothDevice device;
#override
_sensorpageState createState() => _sensorpageState();
}
class _sensorpageState extends State<sensorpage> {
final String SERVICE_UUID = "edb91e04-3e19-11ec-9bbc-0242ac130002";
final String CHARACTERISTIC_UUID = "edb920c0-3e19-11ec-9bbc-0242ac130002";
late bool isReady;
//String val1 = "";
//int pot1 = 0;
FlutterBlue flutterBlue = FlutterBlue.instance;
//late StreamSubscription<ScanResult> scanSubScription;
//late BluetoothDevice targetDevice;
late Stream<List<int>> stream;
#override
void initState() {
super.initState();
isReady = false;
connectToDevice();
}
connectToDevice() async {
if (widget.device == null) {
_Pop();
return;
}
Timer(const Duration(seconds: 15), () {
if (!isReady) {
disconnectFromDevice();
_Pop();
}
});
await widget.device.connect();
discoverServices();
}
disconnectFromDevice() {
if (widget.device == null) {
_Pop();
return;
}
widget.device.disconnect();
}
discoverServices() async {
if (widget.device == null) {
_Pop();
return;
}
List<BluetoothService> services = await widget.device.discoverServices();
services.forEach((service) {
if (service.uuid.toString() == SERVICE_UUID) {
service.characteristics.forEach((characteristic) {
if (characteristic.uuid.toString() == CHARACTERISTIC_UUID) {
characteristic.setNotifyValue(!characteristic.isNotifying);
stream = characteristic.value;
setState(() {
isReady = true;
});
}
});
}
});
if (!isReady) {
_Pop();
}
}
Future<bool> _onWillPop() async {
bool shouldPop = false;
await showDialog(
context: context,
builder: (context) =>
AlertDialog(
title: const Text('Are you sure?'),
content: const Text('Do you want to disconnect device and go back?'),
actions: <Widget>[
ElevatedButton(
onPressed: () {
// shouldPop is already false
},
child: const Text('No')),
ElevatedButton(
onPressed: () async {
await disconnectFromDevice();
Navigator.of(context).pop();
shouldPop = true;
},
child: const Text('Yes')),
],
));
return shouldPop;
}
_Pop() {
Navigator.of(context).pop(true);
}
String _dataParser( List<int> dataFromDevice) {
return utf8.decode(dataFromDevice);
}
#override
Widget build(BuildContext context) {
return WillPopScope(
onWillPop: _onWillPop,
child: Scaffold(
appBar: AppBar(
title: const Text('Test'),
),
body: Container(
child: !isReady
? const Center(
child: Text(
"Waiting...",
style: TextStyle(fontSize: 24, color: Colors.red),
),
)
: Container(
child: StreamBuilder<List<int>>(
stream: stream,
builder: (BuildContext context,
AsyncSnapshot<List<int>> snapshot) {
if (snapshot.hasError){
return Text('Error: ${snapshot.error}');
}
if (snapshot.connectionState == ConnectionState.active) {
var currentValue = _dataParser (snapshot.data!);
//val1 = currentValue.split(',')[0];
//pot1 = int.parse(val1);
return Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
const Text('Current value',
style: TextStyle(fontSize: 14)),
Text('${currentValue} jawool',
style: const TextStyle(
fontWeight: FontWeight.bold,
fontSize: 24))
])
);
} else {
return const Text('Check the stream');
}
},
)),
)
));
}
}´
My Problem is that my second container where I display my data is shown as unnecessary but I don´t know why.

Answer 1

I assume you mean this piece of code?
body: Container(
child: !isReady
? const Center(
child: Text(
"Waiting...",
style: TextStyle(fontSize: 24, color: Colors.red),
),
)
: Container(
child: StreamBuilder<List<int>>(
If isReady is true you return Container(child: Container(child: SteamBuilder));
You should change it to this and it should be fine:
body: Container(
child: !isReady
? const Center(
child: Text(
"Waiting...",
style: TextStyle(fontSize: 24, color: Colors.red),
),
)
: StreamBuilder<List<int>>(

Answer 2

The first Container is just wrapping the content based on the boolean and you don't need it. According to the flutter team:
Wrapping a widget in Container with no other parameters set has no effect and makes code needlessly more complex
So instead you can directly do:
body: !isReady ? buildSomething() : Container(....more code);