block16.dart

class Checkout extends StatelessWidget {
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('Checkout')),
      body: StreamBuilder(
        stream: bloc.getStream,
        initialData: bloc.allItems,
        builder: (context, snapshot) {
          return snapshot.data['cart items'].length > 0
              ? Column(
                  children: <Widget>[
                    /// The [checkoutListBuilder] has to be fixed
                    /// in an expanded widget to ensure it 
                    /// doesn't occupy the whole screen and leaves
                    /// room for the the RaisedButton
                    Expanded(child: checkoutListBuilder(snapshot)),
                    RaisedButton(
                      onPressed: () {},
                      child: Text("Checkout"),
                      color: Theme.of(context).primaryColor,
                    ),
                    SizedBox(height: 40)
                  ],
                )
              : Center(child: Text("You haven't taken any item yet"));
        },
      ),
    );
  }
}