@override
Widget build(BuildContext context) {
  return Scaffold(
    backgroundColor: Colors.grey.shade200,
    appBar: AppBar(
      title: Text('Simple Example'),
    ),
    body: SlidingSheet(
      elevation: 8,
      cornerRadius: 16,
      snapSpec: const SnapSpec(
        // Enable snapping. This is true by default.
        snap: true,
        // Set custom snapping points.
        snappings: [0.4, 0.7, 1.0],
        // Define to what the snappings relate to. In this case, 
        // the total available space that the sheet can expand to.
        positioning: SnapPositioning.relativeToAvailableSpace,
      ),
      // The body widget will be displayed under the SlidingSheet
      // and a parallax effect can be applied to it.
      body: Center(
        child: Text('This widget is below the SlidingSheet'),
      ),
      builder: (context, state) {
        // This is the content of the sheet that will get
        // scrolled, if the content is bigger than the available
        // height of the sheet.
        return Container(
          height: 500,
          child: Center(
            child: Text('This is the content of the sheet'),
          ),
        );
      },
    ),
  );
}

void showAsBottomSheet() async {
  final result = await showSlidingBottomSheet(
    context,
    builder: (context) {
      return SlidingSheetDialog(
        elevation: 8,
        cornerRadius: 16,
        snapSpec: const SnapSpec(
          snap: true,
          snappings: [0.4, 0.7, 1.0],
          positioning: SnapPositioning.relativeToAvailableSpace,
        ),
        builder: (context, state) {
          return Container(
            height: 400,
            child: Center(
              child: Material(
                child: InkWell(
                  onTap: () => Navigator.pop(context, 'This is the result.'),
                  child: Padding(
                    padding: const EdgeInsets.all(16),
                    child: Text(
                      'This is the content of the sheet',
                      style: Theme.of(context).textTheme.body1,
                    ),
                  ),
                ),
              ),
            ),
          );
        },
      );
    }
  );

  print(result); // This is the result.
}

@override
Widget build(BuildContext context) {
  return Scaffold(
    backgroundColor: Colors.grey.shade200,
    appBar: AppBar(
      title: Text('Simple Example'),
    ),
    body: Stack(
      children: <Widget>[
        SlidingSheet(
          elevation: 8,
          cornerRadius: 16,
          snapSpec: const SnapSpec(
            snap: true,
            snappings: [112, 400, double.infinity],
            positioning: SnapPositioning.pixelOffset,
          ),
          builder: (context, state) {
            return Container(
              height: 500,
              child: Center(
                child: Text(
                  'This is the content of the sheet',
                  style: Theme.of(context).textTheme.body1,
                ),
              ),
            );
          },
          headerBuilder: (context, state) {
            return Container(
              height: 56,
              width: double.infinity,
              color: Colors.green,
              alignment: Alignment.center,
              child: Text(
                'This is the header',
                style: Theme.of(context).textTheme.body1.copyWith(color: Colors.white),
              ),
            );
          },
          footerBuilder: (context, state) {
            return Container(
              height: 56,
              width: double.infinity,
              color: Colors.yellow,
              alignment: Alignment.center,
              child: Text(
                'This is the footer',
                style: Theme.of(context).textTheme.body1.copyWith(color: Colors.black),
              ),
            );
          },
        ),
      ],
    ),
  );
}

return SheetListenerBuilder(
  // buildWhen can be used to only rebuild the widget when needed.
  buildWhen: (oldState, newState) => oldState.isAtTop != newState.isAtTop,
  builder: (context, state) {
    return AnimatedContainer(
      elevation: !state.isAtTop ? elevation : 0.0,
      duration: const Duration(milliseconds: 400),
      child: child,
    );
  },
);