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markNeedsBuild fails assertion with conditional Drawer #42580
Description
I have a Drawer that is only enabled on the root page, using this code:
drawer: Navigator.of(context).canPop() ? null : Drawer(child: SettingsDrawer()),When I modify a "dark mode" setting in the drawer that causes a rebuild, I get the following error:
════════ Exception caught by widgets library ═══════════════════════════════════
The following assertion was thrown while finalizing the widget tree:
setState() or markNeedsBuild() called when widget tree was locked.
This Scaffold widget cannot be marked as needing to build because the framework is locked.
The widget on which setState() or markNeedsBuild() was called was: Scaffold
dependencies: [_InheritedTheme, MediaQuery, _LocalizationsScope-[GlobalKey#a243d], Directionality]
state: ScaffoldState#e99f6(tickers: tracking 2 tickers)
When the exception was thrown, this was the stack
#0 Element.markNeedsBuild.<anonymous closure>
package:flutter/…/widgets/framework.dart:3692
#1 Element.markNeedsBuild
package:flutter/…/widgets/framework.dart:3702
#2 State.setState
package:flutter/…/widgets/framework.dart:1161
#3 ScaffoldState._drawerOpenedCallback
package:flutter/…/material/scaffold.dart:1399
#4 DrawerControllerState.close
package:flutter/…/material/drawer.dart:405
...
════════════════════════════════════════════════════════════════════════════════
════════ Exception caught by animation library ═════════════════════════════════
'package:flutter/src/widgets/framework.dart': Failed assertion: line 3658 pos 12: '_debugLifecycleState != _ElementLifecycle.defunct': is not true.
════════════════════════════════════════════════════════════════════════════════
In order to reproduce the issue, open the Drawer and tap the Dark Mode switch with the following (simplified) sample app:
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
void main() => runApp(AppConfig());
class Prefs extends ChangeNotifier {
bool _darkMode = false;
bool get darkMode => _darkMode;
set darkMode(bool newValue) {
if (newValue == _darkMode) return;
_darkMode = newValue;
notifyListeners();
}
}
class AppConfig extends StatefulWidget {
_AppConfigState createState() => _AppConfigState();
}
class _AppConfigState extends State<AppConfig> {
final Prefs prefs = Prefs();
@override
Widget build(BuildContext context) {
return ChangeNotifierProvider<Prefs>.value(value: prefs, child: MyApp());
}
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
final prefs = Provider.of<Prefs>(context);
return MaterialApp(
title: 'Test',
theme: ThemeData(brightness: prefs.darkMode ? Brightness.dark : Brightness.light, primarySwatch: Colors.blue),
home: Home(),
);
}
}
class Home extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: Text("test")),
drawer: Navigator.of(context).canPop() ? null : Drawer(child: SettingsDrawer()),
body: Container(),
);
}
}
class SettingsDrawer extends StatelessWidget {
@override
Widget build(BuildContext context) {
final prefs = Provider.of<Prefs>(context);
return Scaffold(
body: ListView(
padding: EdgeInsets.zero,
children: <Widget>[
DrawerHeader(
child: Text('Settings'),
decoration: BoxDecoration(
color: Colors.blue,
),
),
ListTile(
leading: Text("Dark Mode"),
title: Switch(
value: prefs.darkMode,
onChanged: (value) => prefs.darkMode = value,
),
),
],
),
);
}
}
Activity
BondarenkoStas commentedon Oct 12, 2019
@nbros please provide your flutter doctor -v output.
nbros commentedon Oct 12, 2019
flutter doctor -v
Please note that I also tested with master and I got the same error.
TahaTesser commentedon Apr 16, 2020
Issue still exist
flutter doctor -v
darshankawar commentedon Jan 27, 2021
I verified this issue on latest stable and master and can see the assertion failing while switching to dark mode.
error log
flutter doctor -v
maheshj01 commentedon Dec 8, 2022
The issue is no longer reproducible on stable or the master channel.
code sample
flutter doctor -v (mac)
Closing as this seems to be fixed. Incase anyone still encounters the issue. Please feel free to write in the comments and we will reopen it.
Thank you.
github-actions commentedon Mar 5, 2023
This thread has been automatically locked since there has not been any recent activity after it was closed. If you are still experiencing a similar issue, please open a new bug, including the output of
flutter doctor -vand a minimal reproduction of the issue.