main.dart

import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: MyHome(
        now: DateTime.now(),
      ),
    );
  }
}

class MyHome extends StatefulWidget {
  final DateTime now;

  const MyHome({super.key, required this.now});
  @override
  _MyHomeState createState() => _MyHomeState();
}

class _MyHomeState extends State<MyHome> {
  late ScrollController controller;
  late List<DateTime> items;

  @override
  void initState() {
    items = List.generate(
        10, (index) => widget.now.subtract(Duration(days: index)));
    controller = ScrollController()..addListener(_scrollListener);
    super.initState();
  }

  @override
  void dispose() {
    controller.removeListener(_scrollListener);
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Scrollbar(
        controller: controller,
        child: ListView.builder(
          controller: controller,
          itemBuilder: (context, index) {
            return MyCard(
              d: items[index],
            );
          },
          itemCount: items.length,
        ),
      ),
    );
  }

  void _scrollListener() {
    if (controller.position.userScrollDirection == ScrollDirection.forward &&
        controller.position.pixels < 0) {
      items.insertAll(0,
          List.generate(1, (index) => items.first.subtract(Duration(days: 1))));
      // сместиться на высоту карточки
      controller.jumpTo(90);
      setState(() {});
    }

    if (controller.position.extentAfter < 500) {
      controller.jumpTo(-90);
      setState(() {
        items.add(items.last.add(Duration(days: 1)));
      });
    }
  }
}

class MyCard extends StatelessWidget {
  final DateTime d;
  const MyCard({super.key, required this.d});

  @override
  Widget build(BuildContext context) {
    return Container(
      color: Colors.amber[50],
      margin: EdgeInsets.symmetric(horizontal: 16, vertical: 8),
      height: 100,
      child: Center(child: Text(d.toIso8601String().substring(0, 19))),
    );
  }
}