Created
March 27, 2022 23:37
-
-
Save dancojocaru2000/afd666ebadff4e844abd1e4fb8ba9672 to your computer and use it in GitHub Desktop.
StatefulWidget with initState
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
import 'dart:async'; | |
import 'package:flutter/material.dart'; | |
const Color darkBlue = Color.fromARGB(255, 18, 32, 47); | |
void main() { | |
runApp(MyApp()); | |
} | |
class MyApp extends StatelessWidget { | |
@override | |
Widget build(BuildContext context) { | |
return MaterialApp( | |
theme: ThemeData.dark().copyWith( | |
scaffoldBackgroundColor: darkBlue, | |
), | |
debugShowCheckedModeBanner: false, | |
home: _MyPage(), | |
); | |
} | |
} | |
class _MyPage extends StatefulWidget { | |
@override | |
State<_MyPage> createState() => _MyPageState(); | |
} | |
class _MyPageState extends State<_MyPage> { | |
bool flag = true; | |
late Timer t; | |
@override | |
void initState() { | |
super.initState(); | |
t = Timer.periodic( | |
const Duration(seconds: 2), | |
(timer) { | |
setState(() { | |
flag = !flag; | |
}); | |
}, | |
); | |
} | |
@override | |
void dispose() { | |
t.cancel(); | |
super.dispose(); | |
} | |
@override | |
Widget build(BuildContext context) { | |
return Center( | |
child: Column( | |
children: [ | |
Text('Flag: $flag'), | |
_MyToggleWidget( | |
value: flag, | |
onChanged: (newValue) { | |
setState(() { | |
flag = newValue; | |
}); | |
}, | |
), | |
], | |
), | |
); | |
} | |
} | |
class _MyToggleWidget extends StatefulWidget { | |
final bool? value; | |
final void Function(bool) onChanged; | |
const _MyToggleWidget({required this.value, required this.onChanged}); | |
@override | |
State<_MyToggleWidget> createState() => _MyToggleWidgetState(); | |
} | |
class _MyToggleWidgetState extends State<_MyToggleWidget> { | |
bool value = false; | |
@override | |
void initState() { | |
super.initState(); | |
value = widget.value ?? false; | |
} | |
@override | |
void didChangeDependencies() { | |
super.didChangeDependencies(); | |
} | |
@override | |
Widget build(BuildContext context) { | |
return GestureDetector( | |
onTap: () { | |
setState(() { | |
value = !value; | |
}); | |
widget.onChanged(value); | |
}, | |
child: Text( | |
'Toggle: $value', | |
style: DefaultTextStyle.of(context).style.copyWith( | |
color: value ? Colors.green : Colors.red, | |
), | |
), | |
); | |
} | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment