Unable to use this package.

Flutter 0.10.2-pre.53 • channel master • https://github.com/flutter/flutter.git
Framework • revision 549e8e07c6 (4 days ago) • 2018-10-24 14:41:16 -0700
Engine • revision 2586e94122
Tools • Dart 2.1.0-dev.7.1.flutter-45f9462398

Description

All dependencies are migrated to null safety. So we should migrate this package to null safety. Resources

https://www.youtube.com/watch?v=eBr5tlumwlg&feature=youtu.be https://medium.com/dartlang/announcing-dart-null-safety-beta-87610fee6730

Please help me understand the difference between this package and using WidgetsBinding.instance!.addPostFrameCallback in initState. A call back works fine for me, I just don't know if I am missing something? Thanks

in my project i get data from database on initialization, and i want to show dialog after the data is fetched . can this library help me? the dialog pop up even before the data is fetched.

Hi,I try this:

SchedulerBinding.instance.endOfFrame.then((value){
        showDialog(
          context: context,
          builder: (context){
            return Text('hello');
          }
        );
      });

it can work nice!.

import 'package:flutter/material.dart';
import 'package:after_layout/after_layout.dart';

class IntroPage extends StatefulWidget {
  @override
  _IntroPageState createState() => _IntroPageState();
}

class _IntroPageState extends State<IntroPage> with AfterLayoutMixin<IntroPage> {
  BuildContext ctx;
  
@override
  Widget build(BuildContext context) {
    ctx = context;
    return new Scaffold(body: new Container(color: Colors.red));
  }

   @override
  void afterFirstLayout(BuildContext context) {
    // Calling the same function "after layout" to resolve the issue.
    firstRun();
  }

  Future<Null> firstRun() async {
     print("first run");
    
  }
}

please healp! I keep getting 'initState' is inherited as a getter (from 'State') and also a method (from 'AfterLayoutMixin'). thats my page code above.

Hi, I'm happily using this library but I have an error using it with Visual Studio Code. In fact, it's telling me this:

[dart] The class 'AfterLayoutMixin' can't be used as a mixin because it extends a class other than Object. abstract class AfterLayoutMixin<T extends StatefulWidget> extends State<T>

Except this, I have no problems compiling the app.

E/flutter (28609): [ERROR:flutter/lib/ui/ui_dart_state.cc(186)] Unhandled Exception: This widget has been unmounted, so the State no longer has a context (and should be considered defunct).
E/flutter (28609): Consider canceling any active work during "dispose" or using the "mounted" getter to determine if the State is still active.
E/flutter (28609): #0      State.context.<anonymous closure> (package:flutter/src/widgets/framework.dart:1088:9)
E/flutter (28609): #1      State.context (package:flutter/src/widgets/framework.dart:1094:6)
E/flutter (28609): #2      AfterLayoutMixin.initState.<anonymous closure> (package:after_layout/after_layout.dart:10:31)
E/flutter (28609): #3      _rootRunUnary (dart:async/zone.dart:1362:47)
E/flutter (28609): #4      _CustomZone.runUnary (dart:async/zone.dart:1265:19)
E/flutter (28609): #5      _FutureListener.handleValue (dart:async/future_impl.dart:152:18)
E/flutter (28609): #6      Future._propagateToListeners.handleValueCallback (dart:async/future_impl.dart:704:45)
E/flutter (28609): #7      Future._propagateToListeners (dart:async/future_impl.dart:733:32)
E/flutter (28609): #8      Future._completeWithValue (dart:async/future_impl.dart:539:5)
E/flutter (28609): #9      Future._asyncCompleteWithValue.<anonymous closure> (dart:async/future_impl.dart:577:7)
E/flutter (28609): #10     _rootRun (dart:async/zone.dart:1354:13)
E/flutter (28609): #11     _CustomZone.run (dart:async/zone.dart:1258:19)
E/flutter (28609): #12     _CustomZone.runGuarded (dart:async/zone.dart:1162:7)
E/flutter (28609): #13     _CustomZone.bindCallbackGuarded.<anonymous closure> (dart:async/zone.dart:1202:23)
E/flutter (28609): #14     _microtaskLoop (dart:async/schedule_microtask.dart:40:21)
E/flutter (28609): #15     _startMicrotaskLoop (dart:async/schedule_microtask.dart:49:5)
E/flutter (28609): 

Tested on devices:

• Android 11 SDK / API Level 30 (physical release/debug and emulated debug)
• Android 9 Pie / API Level 28 (physical release/debug)

I'm finding that when I implement the afterFirstLayout override, it works fine with debug builds (physical device, and emulated), but with a release build, I'm not seeing anything being drawn by the build method of my StatefulWidget's State class (_LoadingState.build).

I was trying to make a splash screen that drew first, and then did some loading, and once done it would forward the result onto a new Navigator screen.

Hopefully this makes sense:

import 'package:after_layout/after_layout.dart';
import 'package:flutter/material.dart';
import 'dart:io';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  final String title = "My App Title";
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: title,
      theme: ThemeData(
        primarySwatch: Colors.blue,
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      initialRoute: Loading.routeName,
      routes: {
        Loading.routeName: (context) => Loading(),
        Home.routeName: (context) => Home(),
      },
    );
  }
}

class HomeArgs {
  final TimeProvider time;
  HomeArgs(this.time);
}

class Home extends StatelessWidget {
  static const routeName = '/Home';

  @override
  Widget build(BuildContext context) {
    final HomeArgs args = ModalRoute.of(context).settings.arguments;
    final TimeProvider time = args.time;
    return Scaffold(
      body: Center(
          child: Text(
        "Loading...",
        style: TextStyle(fontSize: 30),
      )),
    );
  }
}

class Loading extends StatefulWidget {
  static const routeName = '/';
  @override
  _LoadingState createState() => _LoadingState();
}

class _LoadingState extends State<Loading> with AfterLayoutMixin<Loading> {
  static const int delay = 3;

  @override
  Widget build(BuildContext context) {
	// _LoadingState.build isn't being drawn in release mode
    return Scaffold(
      body: SafeArea(
          child: Center(
              child: Text('Loading Screen. Waiting for $delay seconds'))),
    );
  }

  @override
  void afterFirstLayout(BuildContext context) {
    final time = new TimeProvider();
    sleep(const Duration(seconds: delay));
    Navigator.pushReplacementNamed(
      context,
      Home.routeName,
      arguments: HomeArgs(time),
    );
  }
}

Interestingly, I notice the same behaviour when I use an alternate method:

class _LoadingState extends State<Loading> {

  // ...

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addPostFrameCallback((_) => load(context));
  }

  // ...

  void load(BuildContext context) {
    final time = new TimeProvider();
    sleep(const Duration(seconds: delay));
    Navigator.pushReplacementNamed(
      context,
      Home.routeName,
      arguments: HomeArgs(time),
    );
  }

  // ...

}

I've used this plugin for a while now and I noticed that the callback sometimes is called twice, and I'm certain it's not a problem in my code. So this small fix will ensure that it's indeed called once.

Hi,

I'm experiencing an issue when i use this library,

So i wanted to do Navigator.of(context).pushReplacement inside a stream that called inside afterFirstLayout callback

But, when the pushReplacement is called, the old page's dispose method didn't get called. Frankly, when i call the pushReplacement method inside a button's onTap callback, it did and ran successfully.

Did anybody had a clue or ever experiencing this kind of problem?

Thanks!