RefreshIndicator should appear from the top of the dragged widget where the [GlowingOverscrollIndicator] appears position.

[xu-baolin]

Description

This change fixes that RefreshIndicator does not appear from the top of the dragged widget where the [GlowingOverscrollIndicator] appears position when custom the position of GlowingOverscrollIndicator.

import 'package:flutter/material.dart';

void main() {
  runApp(MaterialApp(home: BugReport(),));
}

class BugReport extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    double leadingPaintOffset = MediaQuery.of(context).padding.top + AppBar().preferredSize.height;
    return RefreshIndicator(
      onRefresh: () {
        return Future.delayed(const Duration(seconds: 3), () => print('onRefresh finished.'));
      },
      child: NotificationListener<OverscrollIndicatorNotification>(
        onNotification: (notification) {
          if (notification.leading) {
            notification.paintOffset = leadingPaintOffset;
          }
          return false;
        },
        child: CustomScrollView(
          slivers: [
            SliverAppBar(title: Text('Custom PaintOffset')),
            SliverToBoxAdapter(
              child: Container(
                color: Colors.amberAccent,
                height: 100,
                child: Center(child: Text('I love Flutter!', style: TextStyle(fontSize: 18.0),)),
              ),
            ),
            SliverFillRemaining(child: FlutterLogo()),
          ],
        ),
      ),
    );
  }
}

Related Issues

Fixes #71819

Tests

I added the following tests:

See files.

[xu-baolin]

should be otherwise, the RefreshIndicator can not receive the notification:

[xu-baolin]

@darrenaustin Hi,
Welcome to review me :)

[darrenaustin]

@xu-baolin, thanks for the contribution. Sorry it has taken me a while to look at this. I just looked at another related PR #72052 and it would appear that would solve this problem as well. Depending on how it lands, the app could just set the displacement (or edgeDistance if that is the decision for the PR) on the RefreshIndicator to match where the glow indicator is starting. Which I think would handle the same situation, but without the need for the RefreshIndicator to handle this case specifically.

Can you take a look at #72052 and see if it wouldn't solve the same issue by just updating your test program with:

    ...

    return RefreshIndicator(
      onRefresh: () {
        return Future.delayed(const Duration(seconds: 3), () => print('onRefresh finished.'));
      },
     displacement: leadingPaintOffset,

    ...

[xu-baolin]

Thanks for reviewing.
I just take a look at that PR,
I think the situation is a bit different. My understanding is that if you change the position of the glow, the position of the indicator should automatically follow, instead of letting the user manually set it, and ensure that the values on both sides are the same to work properly. This is unfriendly.

[xu-baolin]

The key is whether the indicator and glow should appear from the same position by default?
If the answer is yes, should we need also to change the position of the glow when changing the position of the indicator like #72052 ?

[Piinks]

Hey @xu-baolin! I just came across this, would you still like to proceed with this change?

[xu-baolin]

I have no idea, #72052 seems to help this,if you think so,just close this:)

[Piinks]

Thank you! Much appreciated as always. :)

[darrenaustin]

Indeed. Thank you both. I have been meaning to follow up on this for a while and it got buried in my task list.