import 'package:flutter/material.dart';
void main() {
  runApp(SliverPesistentHeaderScrollUpMouse());
}

class SliverPesistentHeaderScrollUpMouse extends StatelessWidget {
  
  @override
  Widget build(BuildContext context) {
    List<Widget> _widgets = [];
    for (int i = 0; i < 200; i++) {
      _widgets.add(
        Container(
          height: 10,
          color: Colors.blue,
        )
      );
    }
    return MaterialApp(
      title: 'Default label',
      home: Scaffold(
        body: CustomScrollView(
          slivers: [
            SliverPersistentHeader(
              floating: true,
              delegate: Header(),
            ),
            SliverList(
              delegate: SliverChildListDelegate(
                _widgets
              ),
            )
          ],
        )
      )
    );
  }
}

class Header extends SliverPersistentHeaderDelegate {

  @override
  Widget build(BuildContext context, double shrinkOffset, bool overlapsContent) {
    return Container(
      height: 50,
      color: Colors.red,
    );
  }

  @override
  double get maxExtent => 50;

  @override
  double get minExtent => 50;

  @override
  bool shouldRebuild(SliverPersistentHeaderDelegate oldDelegate) {
    return false;
  }
}

[√] Flutter (Channel beta, 1.25.0-8.1.pre, on Microsoft Windows [Version 10.0.19041.746], locale pl-PL)
    • Flutter version 1.25.0-8.1.pre at G:\IOT\flutter\flutter
    • Framework revision 8f89f6505b (7 weeks ago), 2020-12-15 15:07:52 -0800
    • Engine revision 92ae191c17
    • Dart version 2.12.0 (build 2.12.0-133.2.beta)

[√] Android toolchain - develop for Android devices (Android SDK version 29.0.2)
    • Android SDK at C:\Users\Radek\AppData\Local\Android\sdk
    • Platform android-29, build-tools 29.0.2
    • Java binary at: C:\Program Files\Android\Android Studio\jre\bin\java
    • Java version OpenJDK Runtime Environment (build 1.8.0_202-release-1483-b03)
    • All Android licenses accepted.

[√] Chrome - develop for the web
    • Chrome at C:\Program Files (x86)\Google\Chrome\Application\chrome.exe

[√] Android Studio (version 3.5)
    • Android Studio at C:\Program Files\Android\Android Studio
    • Flutter plugin version 39.0.3
    • Dart plugin version 191.8423
    • Java version OpenJDK Runtime Environment (build 1.8.0_202-release-1483-b03)

[√] Connected device (2 available)
    • Chrome (web) • chrome • web-javascript • Google Chrome 88.0.4324.104
    • Edge (web)   • edge   • web-javascript • Microsoft Edge 87.0.664.75