The non-abstract class '_NestedScrollPosition' is missing implementations for these members: - ScrollPosition.pointerScroll

[naamapps]

On Flutter 2.0, I get this error when trying to build the app. I use version 2.0.1 of this package - the latest version.

../../../../flutter/.pub-cache/hosted/pub.dartlang.org/extended_nested_scroll_view-2.0.1/lib/src/old_extended_nested_scroll_view.dart:1229:7: Error: The non-abstract class '_NestedScrollPosition' is missing implementations for these members:
 - ScrollPosition.pointerScroll                                         
Try to either                                                           
 - provide an implementation,                                           
 - inherit an implementation from a superclass or mixin,                
 - mark the class as abstract, or                                       
 - provide a 'noSuchMethod' implementation.                             

class _NestedScrollPosition extends ScrollPosition                      
      ^^^^^^^^^^^^^^^^^^^^^                                             
../../../../flutter/packages/flutter/lib/src/widgets/scroll_position.dart:777:8: Context: 'ScrollPosition.pointerScroll' is defined here.
  void pointerScroll(double delta);           

Please help, Thanks

[zmtzawqlp]

pls get 3.0.0

[yasinarik]

pls get 3.0.0

Version 3.0.0 is for null safety but we can't convert to null-safety yet.

Version extended_nested_scroll_view: ^1.0.1 was working before but it doesn't any more :/

Error Code

../../../.pub-cache/hosted/pub.dartlang.org/extended_nested_scroll_view-2.0.1/lib/src/old_extended_nested_scroll_view.dart:1229:7: Error: The non-abstract class '_NestedScrollPosition' is missing implementations for these members:
 - ScrollPosition.pointerScroll
Try to either
 - provide an implementation,
 - inherit an implementation from a superclass or mixin,
 - mark the class as abstract, or
 - provide a 'noSuchMethod' implementation.

class _NestedScrollPosition extends ScrollPosition
      ^^^^^^^^^^^^^^^^^^^^^
../../../fvm/versions/1.25.0-4.0.pre/packages/flutter/lib/src/widgets/scroll_position.dart:778:8: Context: 'ScrollPosition.pointerScroll' is defined here.
  void pointerScroll(double delta);
       ^^^^^^^^^^^^^

I have tried all of them:

• 3.0.0
• 2.0.1-dev
• 2.0.1
• 2.0.0
• 1.0.1

What can you do for solving it? Thank you very much!

[naamapps]

@yasinarik you don't have to be full null safety. You can be unsound null safety, so your code can be non null safe, but packages can be null safe and it will work properly.

[yasinarik]

@naamapps Hey thanks for the reply! I am currently using Flutter 1.25.0-4.0.pre. Because of that I cannot upgrade the package at the moment.

I have checked if all the packages we have in our project support null safety and yes, they do. I am going to upgrade the SDK first. After the upgrade I will try the 3.0.0version of Extended Nested Scroll View.

[naamapps]

@yasinarik no problem! Just so you know, you can upgrade the flutter version and nothing really happens until you change Dart sdk version. I'm also not on null safety yet but on flutter 2.0.4 and Dart 2.11 (null safety is on 2.12) and everything works fine - some packages are on null safety and others not yet.

[yasinarik]

@naamapps hmm.. So how can I use the 3.0.0 version of this package without upgrading nor migrating to null safety?

I get errors. Just couldn't figure it out. 🙄🤔

(BTW, although seeing those numbers is upsetting the covid app you made is very good. Congrats on that.)

[naamapps]

@yasinarik, if you prefer sticking with flutter 1.25 it's also fine, but it is possible. Search unsound null safety on Google.

And thanks a lot! I made the covid app just for the experience. Glad you liked it.