Fancy Scaffold using Slivers

custom_scaffold.dart

class CustomScaffold extends StatelessWidget {
  const CustomScaffold._({
    Key key,
    this.title,
    this.color,
    this.sliverChildDelegate,
    this.padding = const EdgeInsets.symmetric(horizontal: 20, vertical: 10),
    this.actions,
    this.onRefresh,
  }) : super(key: key);

  factory CustomScaffold({
    Key key,
    String title,
    Color color,
    List<Widget> actions,
    List<Widget> children,
    EdgeInsets padding = const EdgeInsets.symmetric(horizontal: 20, vertical: 10),
    RefreshCallback onRefresh
  }) => CustomScaffold._(
      key: key,
      title: title,
      color: color,
      actions: actions,
      padding: padding,
      onRefresh: onRefresh,
      sliverChildDelegate: SliverChildListDelegate(children)
  );

  factory CustomScaffold.builder({
    Key key,
    String title,
    Color color,
    IndexedWidgetBuilder builder,
    int childCount,
    List<Widget> actions,
    RefreshCallback onRefresh,
    EdgeInsets padding = const EdgeInsets.symmetric(horizontal: 20, vertical: 10),
  }) => CustomScaffold._(
      key: key,
      title: title,
      color: color,
      actions: actions,
      padding: padding,
      onRefresh: onRefresh,
      sliverChildDelegate: SliverChildBuilderDelegate(
          builder,
          childCount: childCount
      )
  );

  final String title;

  final Color color;

  final List<Widget> actions;

  final EdgeInsets padding;

  final SliverChildDelegate sliverChildDelegate;

  final RefreshCallback onRefresh;

  @override
  Widget build(BuildContext context) {
    Widget body = CustomScrollView(
        slivers: <Widget>[
          SliverAppBar(
            floating: true,
            elevation: 1,
            backgroundColor: Colors.white,
            actions: actions,
            title: Text(title, style: const TextStyle(fontSize: 18)),
          ),
          SliverPadding(
              padding: padding,
              sliver: SliverList(delegate: sliverChildDelegate)
          )
        ]
    );


    if (onRefresh != null) {
      body = RefreshIndicator(
        child: body,
        onRefresh: onRefresh,
      );
    }

    return Scaffold(
        backgroundColor: Colors.white,
        body: body
    );
  }
}