iOSのLINEの設定画面のような全画面のDialogをFlutterで実装する

showModalBottomSheet<void>(
      context: context,
      isScrollControlled: true,
      builder: (context) {
            return DraggableScrollableSheet();
      }
);

import 'package:flutter/material.dart';

class SwipableFullModalView extends StatefulWidget {
  const SwipableFullModalView({@required this.child});
  final Widget child;

  @override
  _SwipableFullModalViewState createState() => _SwipableFullModalViewState();
}

class _SwipableFullModalViewState extends State<SwipableFullModalView>
    with SingleTickerProviderStateMixin {
  AnimationController _controller;
  Animation<double> _animation;

  double _height;

  @override
  void initState() {
    super.initState();
    expand();
  }

  Future<void> expand() async {
    _controller = AnimationController(
      duration: const Duration(milliseconds: 200),
      vsync: this,
    );
    final tween = Tween<double>(begin: _controller.value, end: 1);
    _animation = _controller
        .drive(CurveTween(curve: Curves.fastOutSlowIn))
        .drive(tween);
    await _controller.forward();
  }

  @override
  void didChangeDependencies() {
    super.didChangeDependencies();
    _height ??= MediaQuery.of(context).size.height;
  }

  @override
  Widget build(BuildContext context) {
    return AnimatedBuilder(
      animation: _animation,
      builder: (context, child) {
        final ratio = _controller.value;
        final top = _height - _height * ratio;
        return Stack(
          children: [
            Positioned(
              top: top,
              left: 0,
              child: child,
            ),
          ],
        );
      },
      child: GestureDetector(
        onVerticalDragUpdate: (details) {
          final delta = -details.primaryDelta;
          _controller.value += delta / _height;
        },
        onVerticalDragEnd: (details) {
          if (_controller.value < 0.9) {
            _controller.value = 0;
          } else {
            _controller.value = 1;
          }
        },
        child: SizedBox(
          width: MediaQuery.of(context).size.width,
          height: MediaQuery.of(context).size.height,
          child: widget.child,
        ),
      ),
    );
  }
}

showModalBottomSheet<void>(
      context: context,
      isScrollControlled: true,
      builder: (context) {
            return SwipableFullModalView (
                 child: DraggableScrollableSheet(
                     child: HogeListView() // 内部のスクロール出来るWidgetなど色々実装
                 ),
            );
      }
);