ticket_card.dart

class TicketCard extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return ClipPath(
      clipper: TicketClipper(10.0),
      child: Material(
        elevation: 4.0,
        shadowColor: Color(0x30E5E5E5),
        color: Colors.transparent,
        child: ClipPath(
          clipper: TicketClipper(12.0),
          child: Card(
            elevation: 0.0,
            margin: const EdgeInsets.all(2.0),
            child: _buildCardContent(),
          ),
        ),
      ),
    );
  }
  [...]
}

class TicketClipper extends CustomClipper<Path> {
  final double radius;

  TicketClipper(this.radius);

  @override
  Path getClip(Size size) {
    var path = new Path();
    path.lineTo(0.0, size.height);
    path.lineTo(size.width, size.height);
    path.lineTo(size.width, 0.0);
    path.addOval(
        Rect.fromCircle(center: Offset(0.0, size.height / 2), radius: radius));
    path.addOval(
        Rect.fromCircle(center: Offset(size.width, size.height / 2), radius: radius));
    return path;
  }

  @override
  bool shouldReclip(CustomClipper<Path> oldClipper) => true;
}