start.dart

class TransactionListItem extends StatefulWidget {
  final Transaction transaction;

  const TransactionListItem({Key key, @required this.transaction})
      : super(key: key);

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

class _TransactionListItemState extends State<TransactionListItem> {

  @override
  Widget build(BuildContext context) {
    return Card(
      child: Padding(
        padding: const EdgeInsets.all(16.0),
        child: Row(
          children: <Widget>[
            Text(
              widget.transaction.date,
              style: Theme.of(context).textTheme.body1
            ),
            Spacer(),
            Text(
              widget.transaction.amount,
              style: Theme.of(context).textTheme.caption,
            ),
          ],
        ),
      ),
    );
  }
}