stretchy_header.dart:208:22: Warning: Operand of null-aware operation '!' has type 'WidgetsBinding' which excludes null

[Varuhoord]

Using stretchy_header: ^2.0.0 with a flutter project
Just running the app

Launching lib\main.dart on sdk gphone64 x86 64 in debug mode...
Running Gradle task 'assembleDebug'...
√ Built build\app\outputs\flutter-apk\app-debug.apk.
Installing build\app\outputs\flutter-apk\app.apk...
Debug service listening on ws://127.0.0.1:52648/4rKioPesLg8=/ws
Syncing files to device sdk gphone64 x86 64...
/C:/src/flutter/.pub-cache/hosted/pub.dartlang.org/stretchy_header-2.0.0/lib/stretchy_header.dart:208:22: Warning: Operand of null-aware operation '!' has type 'WidgetsBinding' which excludes null.

• 'WidgetsBinding' is from 'package:flutter/src/widgets/binding.dart' ('/C:/src/flutter/packages/flutter/lib/src/widgets/binding.dart').
  WidgetsBinding.instance!.addPostFrameCallback(_onLayoutDone);
  ^
  /C:/src/flutter/.pub-cache/hosted/pub.dartlang.org/stretchy_header-2.0.0/lib/stretchy_header.dart:218:22: Warning: Operand of null-aware operation '!' has type 'WidgetsBinding' which excludes null.
• 'WidgetsBinding' is from 'package:flutter/src/widgets/binding.dart' ('/C:/src/flutter/packages/flutter/lib/src/widgets/binding.dart').
  WidgetsBinding.instance!.addPostFrameCallback(_onLayoutDone);
  ^
  W/Parcel ( 6383): Expecting binder but got null!
  D/EGL_emulation( 6383): app_time_stats: avg=712.17ms min=34.27ms max=1934.67ms count=3
  D/EGL_emulation( 6383): app_time_stats: avg=22.46ms min=5.75ms max=152.90ms count=34

---

Also on your github main page for stretchy_header ( https://github.com/diegoveloper/flutter_stretchy_header/ ) , your instructions are to use version 1.0.8 ?

"Getting started
You should ensure that you add the router as a dependency in your flutter project.

dependencies:
stretchy_header: "^1.0.8" " ?

[diegoveloper]

oh I think this is related to the latest changes on Flutter 3.x, would you mind to send a PR?

[Varuhoord]

Yes, I'm using the latest
version: 1.0.0+1

environment:
sdk: ">=2.17.5 <3.0.0"

What is a PR?

[diegoveloper]

pull request

[Varuhoord]

I want to help but I don't understand how would a pull request help? A pull request on what? I don't even know how to send that, let alone how the process would work, would we review the part of the code where the library is used in my project? The whole code? The project is not on github, however here is a part of the code where it is used in the project. I can't send the whole code. -->

HeaderData buildHeaderData(BuildContext context, Model model) {
return HeaderData(
highlightHeaderAlignment: HighlightHeaderAlignment.top,
highlightHeader: Container(

  @override

Widget build(BuildContext context) {
return Scaffold(
body: StretchyHeader.singleChild(
headerData: buildHeaderData(context, widget.model!),
child: Padding(
padding: EdgeInsets.symmetric(horizontal: 25, vertical: 0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [

        ],
      ),
    ),
  ),

However I think the warning is pointing to this class, line 208 and line 218 in the library

https://github.com/diegoveloper/flutter_stretchy_header/blob/master/lib/stretchy_header.dart

line 208
WidgetsBinding.instance!.addPostFrameCallback(_onLayoutDone);
and line 218
WidgetsBinding.instance!.addPostFrameCallback(_onLayoutDone);

stretchy_header.dart:218:22: Warning: Operand of null-aware operation '!' has type 'WidgetsBinding' which excludes null

[diegoveloper]

I want to help but I don't understand how would a pull request help? A pull request on what? I don't even know how to send that, let alone how the process would work, would we review the part of the code where the library is used in my project? The whole code? The project is not on github, however here is a part of the code where it is used in the project. I can't send the whole code. -->

HeaderData buildHeaderData(BuildContext context, Model model) { return HeaderData( highlightHeaderAlignment: HighlightHeaderAlignment.top, highlightHeader: Container(

  @override

Widget build(BuildContext context) { return Scaffold( body: StretchyHeader.singleChild( headerData: buildHeaderData(context, widget.model!), child: Padding( padding: EdgeInsets.symmetric(horizontal: 25, vertical: 0), child: Column( crossAxisAlignment: CrossAxisAlignment.start, children: [

        ],
      ),
    ),
  ),

However I think the warning is pointing to this class, line 208 and line 218 in the library

https://github.com/diegoveloper/flutter_stretchy_header/blob/master/lib/stretchy_header.dart

line 208 WidgetsBinding.instance!.addPostFrameCallback(_onLayoutDone); and line 218 WidgetsBinding.instance!.addPostFrameCallback(_onLayoutDone);

stretchy_header.dart:218:22: Warning: Operand of null-aware operation '!' has type 'WidgetsBinding' which excludes null

The issue is on my code, (Actually is just a warning), the IDE told you the line with warning /stretchy_header-2.0.0/lib/stretchy_header.dart:218:22

https://opensource.com/article/19/7/create-pull-request-github

Otherwise I could take a look these days.

[Varuhoord]

I forked the project but it's made in flutter v1. Made a new project, copied images and classes, changed stretchy_header.dart

line 208 to
WidgetsBinding.instance.addPostFrameCallback(_onLayoutDone);

line 218 to
WidgetsBinding.instance.addPostFrameCallback(_onLayoutDone);

Now those warnings are gone, I get this

D/skia (10823): Shader compilation error
D/skia (10823): ------------------------
D/skia (10823): Errors:
D/skia (10823): link failed but did not provide an info log
D/skia (10823): Shader compilation error
D/skia (10823): ------------------------
D/skia (10823): Errors:
D/skia (10823): link failed but did not provide an info log
D/skia (10823): Shader compilation error
D/skia (10823): ------------------------
D/skia (10823): Errors:
D/skia (10823): link failed but did not provide an info log
D/skia (10823): Shader compilation error
D/skia (10823): ------------------------
D/skia (10823): Errors:
D/skia (10823): link failed but did not provide an info log
D/skia (10823): Shader compilation error
D/skia (10823): ------------------------
D/skia (10823): Errors:
D/skia (10823): link failed but did not provide an info log
W/Parcel (10823): Expecting binder but got null!

But no red warnings and it works, so just remove those exclamation points, it should be enough. Best regards.