Playing with draggable scrollable sheet

main.dart

import 'package:flutter/foundation.dart';
import 'package:flutter/gestures.dart';
import 'package:flutter/material.dart';

/// Flutter code sample for [DraggableScrollableSheet].

void main() => runApp(const DraggableScrollableSheetExampleApp());

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      scrollBehavior: MaterialScrollBehavior().copyWith(dragDevices: PointerDeviceKind.values.toSet()),
      theme: ThemeData(colorScheme: ColorScheme.fromSeed(seedColor: Colors.blue.shade100)),
      home: Scaffold(
        appBar: AppBar(title: const Text('DraggableScrollableSheet Sample')),
        body: const DraggableScrollableSheetExample(),
      ),
    );
  }
}

class DraggableScrollableSheetExample extends StatefulWidget {
  const DraggableScrollableSheetExample({super.key});

  @override
  State<DraggableScrollableSheetExample> createState() => _DraggableScrollableSheetExampleState();
}

class _DraggableScrollableSheetExampleState extends State<DraggableScrollableSheetExample> {
  double _sheetPosition = 0.5;
  final double _dragSensitivity = 600;

  @override
  Widget build(BuildContext context) {
    final ColorScheme colorScheme = Theme.of(context).colorScheme;

    return DraggableScrollableSheet(
      initialChildSize: _sheetPosition,
      builder: (BuildContext context, ScrollController scrollController) {
        return ColoredBox(
          color: colorScheme.primary,
          child: Column(
            children: <Widget>[
              // Header wrapper with gesture?
              Container(height: 50, color: Colors.green),
              Flexible(
                child: ListView.builder(
                  controller: scrollController,
                  itemCount: 25,
                  itemBuilder: (BuildContext context, int index) {
                    return ListTile(
                      title: Text('Item $index', style: TextStyle(color: colorScheme.surface)),
                    );
                  },
                ),
              ),
            ],
          ),
        );
      },
    );
  }
}