Widget does not update properly after CircularProgressIndicator - flutter

Question

I was trying to display a progress indicator on my app on flutter while it's loading. If I don't use it, the app works properly and the data load, but when I add the progress indicator, after it disappears, the app shows only the containers' borders or colors, without the data in them. How can I solve?
Here's the code of the main page:
void main() {
runApp(const MyApp());
}
class MyApp extends StatefulWidget {
const MyApp({super.key});
#override
MyAppState createState() => MyAppState();
}
class MyAppState extends State<MyApp> {
bool isLoaded = false;
#override
void initState() {
super.initState();
DataSync data = DataSync();
data.getInitialData();
globals.isLoaded.addListener(() {
setState(() {
isLoaded = true;
});
});
}
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'MainPage',
home: Scaffold(resizeToAvoidBottomInset: false, body: inizializeApp() ),
debugShowCheckedModeBanner: false,
);
}
Container inizializeApp() {
return Container(
decoration: const BoxDecoration(
gradient: LinearGradient(
begin: Alignment.topRight,
end: Alignment.bottomCenter,
colors: [
Color.fromARGB(255, 24, 26, 38),
Color.fromARGB(255, 1, 0, 5),
])),
//height: 500,
padding: const EdgeInsets.all(8),
child: Center(
child: isLoaded
? ListView(
physics: const NeverScrollableScrollPhysics(),
children: const [
SizedBox(height: 70, child: WeatherWidgets()),
SizedBox(height: 70, child: WeekDayWidget()),
SizedBox(height: 50, child: DateWidget()),
DataWidget(),
],
)
: const CircularProgressIndicator()),
);
}
}
and the class where I update the globals containing the data:
ValueNotifier<WeatherForecastResult> forecastResultNotifier =
ValueNotifier<WeatherForecastResult>(WeatherForecastResult.noParam());
ValueNotifier<int> selectedIndex = ValueNotifier<int>(0);
ValueNotifier<bool> isLoaded = ValueNotifier<bool>(false);
class DataSync {
Geolocation geolocation = Geolocation();
WeatherForecastResult forecastResult = WeatherForecastResult.noParam();
Weather weather = Weather();
getInitialData() async {
Position position = await geolocation.determinePosition();
forecastResult =
await weather.getForecast(position.latitude, position.longitude);
forecastResultNotifier.value = forecastResult;
isLoaded.value = true;
}
}
Tried various widget for the progress indicator, but the problem doesn't disappear

Answer 1

I tried to reproduce the problem - and failed! Could you check this simplified version (that should be complete in itself and run instantly) and try to reproduce the error? Or could you write a shortened version that is complete to run and reproduces the mistake? Then I would be happy to try to find out more!
import 'package:flutter/material.dart';
ValueNotifier<bool> globalIsLoaded = ValueNotifier<bool>(false);
class MyAppState extends State<MyApp> {
bool isLoaded = false;
Container initializeApp() {
return Container(
child: Center(
child: isLoaded
? const Text('is loaded')
: const CircularProgressIndicator(),
));
}
Container anotherInitializeApp() {
return Container(
child: Center(
child: ValueListenableBuilder(
builder: (BuildContext context, bool valueFromGlobalIsLoaded,
Widget? child) {
return valueFromGlobalIsLoaded
? const Text('is loaded')
: const CircularProgressIndicator();
},
valueListenable:
globalIsLoaded, // <-- ignores local isLoaded, so you would not need an addListener
),
));
}
#override
void initState() {
super.initState();
DataSync data = DataSync();
// data.getInitialData(); <-- moved it down after the addListener (but should not be decicive if this function is not super fast)
globalIsLoaded.addListener(() {
setState(() {
isLoaded = true;
});
});
data.getInitialData();
}
#override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
body: initializeApp(), // try also: body: anotherInitializeApp(),
),
);
}
}
class DataSync {
getInitialData() async {
await Future.delayed(const Duration(seconds: 2));
globalIsLoaded.value = true;
}
}
class MyApp extends StatefulWidget {
const MyApp({super.key});
#override
MyAppState createState() => MyAppState();
}
void main() => runApp(MyApp());