Sliverappbar stretch effect

[himalaya-nuts]

Fixes issue: Unable to stretch SliverAppBar issue

This is a quick hack, optimal effect requires extensive refactoring, thus official Flutter team is not picking up this issue. Some limitations apply:

1. The body scroll view must have BouncingScrollPhysics, when the SliverAppBar background stretches, so does the body scroll view.
2. SliverAppBar and body scroll physics does not connect seamlessly. As a result, the SliverAppBar won't stretch by carried momentum (when you quick fling down then not touching the screen), your fingertip has to be touching the screen when stretching the SliverAppBar.

See scroll to top demo to have a play.

[nghiadinhTiki]

this should be innerPosition.pixels <= 0.0, if use equal, sometimes, inner scrollview is not scroll to top

[himalaya-nuts]

thanks!

[Ruslanbek0809]

Hi I used your commit. When I use stretch I get errors like these:
'package:extended_nested_scroll_view/src/old_extended_nested_scroll_view.dart': Failed assertion: line 832 pos 16: 'minRange <= maxRange': is not true.

'package:flutter/src/widgets/scrollable.dart': Failed assertion: line 628 pos 12: '_drag == null': is not true.

Are there any solutions?

[flutting]

你的代码已经报错了, 需要改一下才能运行, 这样是不能合并的.

[akbulutdora]

Does anyone follow this PR or this problem anymore? If you've found a solution, what was it?

[zmtzawqlp]

i'm waiting an official pr, if you have a good idea, you can push a pr to flutter team. i must make sure the codes will not breaking any other function

[akbulutdora]

I understand. My question was regarding this problem with the outer body overscrolling/stretching at the top (for refresh effect similar to popular social media apps) and load more effect with the bottom (i can actually achieve this one myself using the infinite_scroll_pagination package). Could not achieve a proper refresh effect so far.

[fikretsengul]

I'm trying to simulate the app bar large title stretch effect in iOS, it would be great if we could especially fix the 2nd problem and add this as a feature for this package. @zmtzawqlp