Flutter - Stacked Card List

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

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

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('StackedListScreen')),
      body: const StackedList(),
    );
  }
}

class StackedList extends StatelessWidget {
  final List<Color> _colors = Colors.primaries;
  static const _minHeight = 16.0;
  static const _maxHeight = 120.0;

  const StackedList({super.key});

  @override
  Widget build(BuildContext context) => CustomScrollView(
        slivers: _colors
            .map(
              (color) => StackedListChild(
                minHeight: _minHeight,
                maxHeight: _colors.indexOf(color) == _colors.length - 1
                    ? MediaQuery.of(context).size.height
                    : _maxHeight,
                pinned: true,
                child: Container(
                  color: _colors.indexOf(color) == 0
                      ? Colors.black
                      : _colors[_colors.indexOf(color) - 1],
                  child: Container(
                    decoration: BoxDecoration(
                      borderRadius: const BorderRadius.vertical(
                          top: Radius.circular(_minHeight)),
                      color: color,
                    ),
                  ),
                ),
              ),
            )
            .toList(),
      );
}

class StackedListChild extends StatelessWidget {
  final double minHeight;
  final double maxHeight;
  final bool pinned;
  final bool floating;
  final Widget child;

  SliverPersistentHeaderDelegate get _delegate => _StackedListDelegate(
      minHeight: minHeight, maxHeight: maxHeight, child: child);

  const StackedListChild({
    super.key,
    required this.minHeight,
    required this.maxHeight,
    required this.child,
    this.pinned = false,
    this.floating = false,
  });

  @override
  Widget build(BuildContext context) => SliverPersistentHeader(
      key: key, pinned: pinned, floating: floating, delegate: _delegate);
}

class _StackedListDelegate extends SliverPersistentHeaderDelegate {
  final double minHeight;
  final double maxHeight;
  final Widget child;

  _StackedListDelegate({
    required this.minHeight,
    required this.maxHeight,
    required this.child,
  });

  @override
  double get minExtent => minHeight;

  @override
  double get maxExtent => max(maxHeight, minHeight);

  @override
  Widget build(
      BuildContext context, double shrinkOffset, bool overlapsContent) {
    return SizedBox.expand(child: child);
  }

  @override
  bool shouldRebuild(_StackedListDelegate oldDelegate) {
    return maxHeight != oldDelegate.maxHeight ||
        minHeight != oldDelegate.minHeight ||
        child != oldDelegate.child;
  }
}