I'm trying to transition to navigate from a stateful widget (MyStatefulWidget) to a stateless one (SettingsScreen) while animating both screens. But the old screen/route shows an outdated version when it is moving.
I suspect the problem is in the createMoveRoute function that is being passed outChild
which is the stateful widget. But it doesn't seem to work.
How can I show the most recent stateful widget for the transition?
It has two tabs: the home that doesn't navigate anywhere and the settings tab that navigates to a different page.
main.dart
import 'package:flutter/material.dart';
Route createMoveRoute(Widget outChild, Widget destination) {
return PageRouteBuilder(
pageBuilder: (context, animation, secondaryAnimation) => destination,
transitionDuration: const Duration(seconds: 2),
transitionsBuilder: (context, animation, secondaryAnimation, newChild) {
const curve = Curves.easeInOut;
var outTween = Tween(begin: Offset.zero, end: const Offset(-1.0, 0.0))
.chain(CurveTween(curve: curve));
var newTween = Tween(begin: const Offset(1.0, 0.0), end: Offset.zero)
.chain(CurveTween(curve: curve));
return Stack(
children: [
SlideTransition(
position: animation.drive(outTween),
child: outChild,
),
SlideTransition(
position: animation.drive(newTween),
child: newChild,
),
],
);
},
);
}
void main() => runApp(const MyApp());
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
static const String _title = 'Flutter Code Sample';
@override
Widget build(BuildContext context) {
return const MaterialApp(
title: _title,
home: MyStatefulWidget(),
);
}
}
class MyStatefulWidget extends StatefulWidget {
const MyStatefulWidget({Key? key}) : super(key: key);
@override
State<MyStatefulWidget> createState() => _MyStatefulWidgetState();
}
class _MyStatefulWidgetState extends State<MyStatefulWidget> {
int _selectedIndex = 0;
static const TextStyle optionStyle =
TextStyle(fontSize: 30, fontWeight: FontWeight.bold);
void _onItemTapped(int index) {
setState(() {
_selectedIndex = index;
});
}
@override
Widget build(BuildContext context) {
List<Widget> _widgetOptions = <Widget>[
const Text(
'Press settings at the bottom',
style: optionStyle,
),
ElevatedButton(
onPressed: () {
Navigator.of(context).push(
createMoveRoute(widget, const SettingsScreen()),
);
},
child: const Text('Go to settings'),
),
];
return Scaffold(
appBar: AppBar(
title: const Text('BottomNavigationBar Sample'),
),
body: Center(
child: _widgetOptions.elementAt(_selectedIndex),
),
bottomNavigationBar: BottomNavigationBar(
items: const <BottomNavigationBarItem>[
BottomNavigationBarItem(
icon: Icon(Icons.home),
label: 'Home',
),
BottomNavigationBarItem(
icon: Icon(Icons.settings),
label: 'Settings',
),
],
currentIndex: _selectedIndex,
onTap: _onItemTapped,
),
);
}
}
class SettingsScreen extends StatelessWidget {
const SettingsScreen({Key? key}) : super(key: key);
@override
Widget build(BuildContext context) {
return const Scaffold(
body: Center(
child: Text("Settings"),
),
);
}
}
This is how to animate a transition with a stateful widget that moves both the old and new routes/widgets.
The solution is to apply the transitions to both widgets when they are loaded. This can be done with page routes. So, when a route leaves, it doesn't listen to the new animation, it listens to its own secondaryAnimation.
Background: I was browsing this issue for Flutter and found this solution. I adapted the solution to fit my needs below.
main.dart
import 'package:flutter/material.dart';
void main() => runApp(const MyApp());
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(primaryColor: Colors.white),
initialRoute: '/',
onGenerateInitialRoutes: (initialRoute) =>
[createCustomTransition(HomeScreen())],
onGenerateRoute: (settings) {
if (settings.name == '1') {
return createCustomTransition(const SettingsScreen());
}
},
debugShowCheckedModeBanner: false,
);
}
}
PageRouteBuilder createCustomTransition(Widget screen) {
return PageRouteBuilder(
transitionDuration: const Duration(milliseconds: 700),
reverseTransitionDuration: const Duration(milliseconds: 700),
pageBuilder: (context, animation, secondaryAnimation) => screen,
transitionsBuilder: (context, animation, secondaryAnimation, child) {
final slideAnimation = Tween(
begin: const Offset(1.0, 0.0),
end: Offset.zero,
).animate(CurvedAnimation(
curve: Curves.easeInOut,
reverseCurve: Curves.easeInOut,
parent: animation,
));
final slideOutAnimation = Tween(
begin: Offset.zero,
end: const Offset(-1.0, 0.0),
).animate(CurvedAnimation(
curve: Curves.easeInOut,
reverseCurve: Curves.easeInOut,
parent: secondaryAnimation,
));
return SlideTransition(
position: slideAnimation,
child: SlideTransition(
position: slideOutAnimation,
child: child,
),
);
},
);
}
class HomeScreen extends StatefulWidget {
HomeScreen({Key? key}) : super(key: key);
@override
State<HomeScreen> createState() => _HomeScreenState();
}
class _HomeScreenState extends State<HomeScreen> {
final List<int> list = List.generate(1000, (index) => index);
int _selectedIndex = 0;
static const TextStyle optionStyle =
TextStyle(fontSize: 30, fontWeight: FontWeight.bold);
void _onItemTapped(int index) {
setState(() {
_selectedIndex = index;
});
}
@override
Widget build(BuildContext context) {
List<Widget> _widgetOptions = <Widget>[
const Text(
'Press settings at the bottom',
style: optionStyle,
),
ElevatedButton(
onPressed: () {
Navigator.of(context).pushNamed("1");
},
child: const Text('Go to settings'),
),
];
return Scaffold(
appBar: AppBar(
title: const Text('BottomNavigationBar Sample'),
),
body: Center(
child: _widgetOptions.elementAt(_selectedIndex),
),
bottomNavigationBar: BottomNavigationBar(
items: const <BottomNavigationBarItem>[
BottomNavigationBarItem(
icon: Icon(Icons.home),
label: 'Home',
),
BottomNavigationBarItem(
icon: Icon(Icons.settings),
label: 'Settings',
),
],
currentIndex: _selectedIndex,
onTap: _onItemTapped,
),
);
}
}
class SettingsScreen extends StatelessWidget {
const SettingsScreen({Key? key}) : super(key: key);
@override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.green.shade100,
body: Center(child: Text('Settings')),
);
}
}
the visuals: