Cupertino Bottom Sheet Route for Router/Navigation 2.0

simple_cupertino_modal_route.dart

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:modal_bottom_sheet/modal_bottom_sheet.dart';

const double _behind_widget_visible_height = 10;
const Radius _default_top_radius = Radius.circular(12);

/// Cupertino Bottom Sheet Container
///
/// Clip the child widget to rectangle with top rounded corners and adds
/// top padding(+safe area padding). This padding [_behind_widget_visible_height]
/// is the height that will be displayed from previous route.
class _CupertinoBottomSheetContainer extends StatelessWidget {
  final Widget child;
  final Color backgroundColor;
  final Radius topRadius;

  const _CupertinoBottomSheetContainer(
      {Key key, this.child, this.backgroundColor, @required this.topRadius})
      : super(key: key);

  @override
  Widget build(BuildContext context) {
    final topSafeAreaPadding = MediaQuery.of(context).padding.top;
    final topPadding = _behind_widget_visible_height + topSafeAreaPadding;

    final shadow =
        BoxShadow(blurRadius: 10, color: Colors.black12, spreadRadius: 5);
    final _backgroundColor =
        backgroundColor ?? CupertinoTheme.of(context).scaffoldBackgroundColor;
    return Padding(
      padding: EdgeInsets.only(top: topPadding),
      child: ClipRRect(
        borderRadius: BorderRadius.vertical(top: topRadius),
        child: Container(
          decoration:
              BoxDecoration(color: _backgroundColor, boxShadow: [shadow]),
          width: double.infinity,
          child: MediaQuery.removePadding(
            context: context,
            removeTop: true, //Remove top Safe Area
            child: child,
          ),
        ),
      ),
    );
  }
}

Widget _defaultContainerBuilder(
    BuildContext context, Animation<double> animation, Widget child) {
  return _CupertinoBottomSheetContainer(
    child: child,
    backgroundColor: Colors.transparent,
    topRadius: _default_top_radius,
  );
}

class SimpleCupertinoModalRoute extends CupertinoModalBottomSheetRoute {
  SimpleCupertinoModalRoute({
    ScrollWidgetBuilder builder,
    WidgetWithChildBuilder containerBuilder = _defaultContainerBuilder,
    double closeProgressThreshold,
    String barrierLabel,
    double elevation,
    ShapeBorder shape,
    Clip clipBehavior,
    AnimationController secondAnimationController,
    Curve animationCurve,
    Color modalBarrierColor,
    bool bounce = true,
    bool isDismissible = true,
    bool enableDrag = true,
    bool expanded = false,
    Duration duration,
    RouteSettings settings,
    ScrollController scrollController,
    Color transitionBackgroundColor,
    Radius topRadius = _default_top_radius,
    Curve previousRouteAnimationCurve,
  })  : assert(expanded != null),
        assert(isDismissible != null),
        assert(enableDrag != null),
        super(
          builder: builder,
          containerBuilder: containerBuilder,
          closeProgressThreshold: closeProgressThreshold,
          barrierLabel: barrierLabel,
          elevation: elevation,
          shape: shape,
          clipBehavior: clipBehavior,
          secondAnimationController: secondAnimationController,
          animationCurve: animationCurve,
          modalBarrierColor: modalBarrierColor,
          bounce: bounce,
          isDismissible: isDismissible,
          enableDrag: enableDrag,
          expanded: expanded,
          duration: duration,
          settings: settings,
          scrollController: scrollController,
          transitionBackgroundColor: transitionBackgroundColor,
          topRadius: topRadius,
          previousRouteAnimationCurve: previousRouteAnimationCurve,
        );
}