Repository: flutter
Issue: Bug Report: Scroll Becomes Unresponsive and Lags Under Multi-Finger Rapid Usage
Labels: waiting for customer response,in triage

<!-- Failed to upload "ScreenRecording_01-15-2025 11-47-58_1.mp4" -->

### Steps to reproduce

Description: When continuously scrolling with repeated and rapid gestures (e.g., using multiple fingers to scroll back and forth rapidly), the scroll view becomes unresponsive and lags severely. The issue occurs consistently under high-frequency interactions involving multiple fingers on the screen.

Steps to Reproduce:

1. Open the application and navigate to a screen with a scrollable widget.
2. Begin scrolling in any direction.
3.Rapidly and repeatedly interact with the scroll view using multiple fingers (e.g., two or more fingers tapping and scrolling simultaneously).
Observe the behavior of the scroll view.
Environment:

Dart SDK: 3.3.2
Flutter SDK: 3.19.4
Device: [Specify the device and OS version]
Scrollable Widget: [Provide details if it's a specific widget like ListView, SingleChildScrollView, etc.]
Additional Notes: The issue appears to be related to simultaneous or conflicting scroll inputs being processed during rapid multi-finger interactions.

### Expected results

The scroll view should remain smooth and responsive, regardless of the frequency or intensity of scrolling interactions.


### Actual results


The scroll view becomes laggy.
Scrolling responsiveness deteriorates significantly.
In some cases, the scroll view stops responding altogether.

### Code sample

```
import 'package:flutter/material.dart';
import 'package:sliver_tools/sliver_tools.dart';

class SliverGridExample extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('SliverTools Grid Example'),
      ),
      body: CustomScrollView(
        slivers: [
          // MultiSliver ใช้รวม Slivers หลายตัวใน ScrollView
          MultiSliver(
            children: [
              SliverPadding(
                padding: EdgeInsets.all(8.0),
                sliver: SliverGrid(
                  gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
                    crossAxisCount: 3, // จำนวนคอลัมน์ใน Grid
                    mainAxisSpacing: 8,
                    crossAxisSpacing: 8,
                    childAspectRatio: 1,
                  ),
                  delegate: SliverChildBuilderDelegate(
                    (BuildContext context, int index) {
                      return Container(
                        color: Colors.blueAccent,
                        child: Center(
                          child: Text(
                            'Item $index',
                            style: TextStyle(color: Colors.white),
                          ),
                        ),
                      );
                    },
                    childCount: 30, // จำนวนไอเท็มใน Grid
                  ),
                ),
              ),
              SliverToBoxAdapter(
                child: Padding(
                  padding: const EdgeInsets.all(16.0),
                  child: Text(
                    'This is a SliverToBoxAdapter after the Grid.',
                    style: TextStyle(fontSize: 16),
                  ),
                ),
              ),
            ],
          ),
        ],
      ),
    );
  }
}

void main() => runApp(MaterialApp(home: SliverGridExample()));

```

### Screenshots or Video



<details open>
<summary>Screenshots / Video demonstration</summary>

[[Upload media here]](https://drive.google.com/file/d/1YVeG9ErhQ4q5OJFlm2fbx7_dk7NiKMD4/view?usp=sharing)

</details>


### Logs

<details open><summary>Logs</summary>

```console
[Paste your logs here]
```

</details>


### Flutter Doctor output

<details open><summary>Doctor output</summary>

```console
[✓] Flutter (Channel stable, 3.19.4, on macOS 15.1.1 24B91 darwin-arm64, locale en-TH)
    • Flutter version 3.19.4 on channel stable at /Users/watcharatep.lnk/fvm/versions/3.19.4
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 68bfaea224 (10 months ago), 2024-03-20 15:36:31 -0700
    • Engine revision a5c24f538d
    • Dart version 3.3.2
    • DevTools version 2.31.1

[✓] Android toolchain - develop for Android devices (Android SDK version 35.0.0)
    • Android SDK at /Users/watcharatep.lnk/Library/Android/sdk/
    • Platform android-35, build-tools 35.0.0
    • ANDROID_HOME = /Users/watcharatep.lnk/Library/Android/sdk
    • Java binary at: /Applications/Android Studio.app/Contents/jbr/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 17.0.6+0-17.0.6b829.9-10027231)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 16.1)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Build 16B40
    • CocoaPods version 1.16.2

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 2022.3)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 17.0.6+0-17.0.6b829.9-10027231)

[✓] VS Code (version 1.96.2)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.102.0
```

</details>