pubspec.yaml
dependencies:
flutter:
sdk: flutter
provider:
shared_preferences:
main.dart
import 'package:flutter/material.dart';
import 'myhomepage.dart';
import 'package:provider/provider.dart';
import 'dummyprovider.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({super.key});
@override
Widget build(BuildContext context) {
return MultiProvider(
providers: [
ChangeNotifierProvider(create: (context) => SettingsProvider()),
],
child: MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: const MyHomePage(title: 'Flutter Demo Home Page'),
),
);
}
}
dummyprovider.dart
import 'package:flutter/material.dart';
import 'dart:async';
import 'package:shared_preferences/shared_preferences.dart';
class SettingsProvider with ChangeNotifier {
late SharedPreferences _sharedPrefs;
bool _displayValuesAsScientific = false;
SettingsProvider() {
initialState().then((value) {
debugPrint("settingsprovider.dart, initialStatecalledthen");
getValueDisplaySetting();
});
}
Future<void> initialState() async {
_sharedPrefs = await SharedPreferences.getInstance();
}
getValueDisplaySetting() {
_displayValuesAsScientific = _sharedPrefs.getBool("settingExponential") ?? false;
notifyListeners();
}
setValueDisplaySetting(bool value) {
_sharedPrefs.setBool("settingExponential", value);
debugPrint("settingsprovider.dart, setValueDisplaySetting as $value");
notifyListeners();
}
bool get displaySetting {
return _displayValuesAsScientific;
}
}
myhomepage.dart
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'dummyprovider.dart';
import 'child.dart';
import 'appdrawer.dart';
class MyHomePage extends StatefulWidget {
const MyHomePage({super.key, required this.title});
final String title;
@override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
String numberOne = "12021321.2131";
String numberTwo = "1233.123";
String numberToShow = "1";
@override
Widget build(BuildContext context) {
final sElement = context.watch<SettingsProvider>();
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
drawer: AppDrawer(),
body: Center(
child: Column(
children: <Widget>[
Container(
height: 50,
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
SizedBox(width: MediaQuery.of(context).size.width * 0.05),
GestureDetector(
onTap: (() {
setState(() {
numberToShow = numberOne;
});
}),
child: Container(
width: MediaQuery.of(context).size.width * 0.45,
color: Colors.black,
child: Center(
child: Text(
"$numberOne",
style: const TextStyle(
fontWeight: FontWeight.bold,
color: Colors.blue,
),
),
),
),
),
GestureDetector(
onTap: (() {
setState(() {
numberToShow = numberTwo;
});
}),
child: Container(
width: MediaQuery.of(context).size.width * 0.45,
color: Colors.amberAccent,
child: Center(
child: Text(
"$numberTwo",
style: const TextStyle(
fontWeight: FontWeight.bold,
color: Colors.red,
),
),
),
),
),
SizedBox(width: MediaQuery.of(context).size.width * 0.05),
],
),
),
const Text(
'Data to show:',
),
Expanded(
child: ChildWidget(numberToShow),
)
],
),
),
);
}
}
appdrawer.dart
import 'package:flutter/material.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'dummyprovider.dart';
import 'package:provider/provider.dart';
class AppDrawer extends StatefulWidget {
@override
State<AppDrawer> createState() => _AppDrawerState();
}
class _AppDrawerState extends State<AppDrawer> {
bool introScreen = false;
String intropref = "false";
SharedPreferences? appPreferences;
bool vibrateSetting = false;
bool settingExponential = false;
@override
void initState() {
super.initState();
setPrefs();
}
void setPrefs() async {
appPreferences = await SharedPreferences.getInstance();
loadPrefIntroSc();
setState(() {
settingExponential = Provider.of<SettingsProvider>(context, listen: false).displaySetting;
});
}
void loadPrefIntroSc() async {
introScreen = appPreferences!.getBool("skipIntro") ?? false;
vibrateSetting = appPreferences!.getBool("vibrateSetting") ?? false;
}
Future<String> getDefaultIntroSetting() async {
return "gotScreenSetting";
}
refresh() {
setState(() {});
}
@override
Widget build(BuildContext context) {
var sElement = context.watch<SettingsProvider>();
return Drawer(
child: ListView(
children: [
FutureBuilder(
future: getDefaultIntroSetting(),
builder: (context, snapshot) {
switch (snapshot.connectionState) {
case ConnectionState.waiting:
return const Center(
child: CircularProgressIndicator(),
);
case ConnectionState.active:
return const Text("active");
case ConnectionState.none:
return const Text("none");
case ConnectionState.done:
return Column(
children: [
// setting for exponential display
Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
const SizedBox(
width: 10,
),
Container(
child: const Text(
"Show as exponential",
style: TextStyle(
color: Colors.black,
),
),
),
Flexible(
child: Container(),
),
Switch(
value: settingExponential,
onChanged: (value) {
sElement.setValueDisplaySetting(value);
settingExponential = value;
}),
const SizedBox(
width: 10,
),
],
),
],
);
default:
return const Text("default");
}
},
),
],
),
);
}
}
child.dart
import 'package:flutter/material.dart';
import 'dummyprovider.dart';
import 'package:provider/provider.dart';
class ChildWidget extends StatefulWidget {
String dataToProcess;
ChildWidget(this.dataToProcess, {Key? key}) : super(key: key);
@override
State<ChildWidget> createState() => _ChildWidgetState();
}
class _ChildWidgetState extends State<ChildWidget> {
@override
Widget build(BuildContext context) {
final sElement = context.watch<SettingsProvider>();
return Center(
child: Text(
sElement.displaySetting
? double.parse(widget.dataToProcess) > 100000 ||
double.parse(widget.dataToProcess) < 0.00001
? double.parse(widget.dataToProcess).toStringAsExponential()
: double.parse(widget.dataToProcess).toString()
: double.parse(widget.dataToProcess).toStringAsFixed(5),
style: Theme.of(context).textTheme.headline4,
),
);
}
}