A progress line that goes from a starting date to an end date

tracking_progress_line.dart

class MyProgressLine extends CustomPainter {
  MyProgressLine({this.shipped, this.estDelivery});

  final DateTime shipped;
  final DateTime estDelivery;

  @override
  void paint(Canvas canvas, Size size) {
    Paint paint = Paint()
      ..color = Colors.green
      ..strokeWidth = 3.0
      ..style = PaintingStyle.stroke;

    double endPointsRadius = 5.0;
    double width = size.width;

    int totalDays = ((estDelivery.millisecondsSinceEpoch - shipped.millisecondsSinceEpoch) / 86400000).floor();
    int currentDay = ((DateTime.now().millisecondsSinceEpoch - shipped.millisecondsSinceEpoch) / 86400000).floor();
    double stepPerDay = width / totalDays;

    // Draws starting point
    canvas.drawCircle(Offset.zero, 5.0, paint);
    canvas.drawLine(Offset(endPointsRadius, 0.0), Offset(endPointsRadius + stepPerDay * currentDay, 0.0), paint);

    // Draws current progress line
    paint.style = PaintingStyle.fill;
    canvas.drawCircle(Offset(endPointsRadius + stepPerDay * currentDay, 0.0), 3.0, paint);

    // Draws endpoint
    paint.style = PaintingStyle.stroke;
    paint.color = Colors.grey.withOpacity(0.5);
    canvas.drawLine(Offset(endPointsRadius + stepPerDay * currentDay, 0.0), Offset(stepPerDay * totalDays, 0.0), paint);
    canvas.drawCircle(Offset((stepPerDay * totalDays) + endPointsRadius, 0.0), endPointsRadius, paint);
  }

  @override
  bool shouldRepaint(CustomPainter oldDelegate) => false;
}

class MySnackBar extends StatefulWidget {
  _MySnackBarState createState() => _MySnackBarState();
}

class _MySnackBarState extends State<MySnackBar> {
  @override
  Widget build(BuildContext context) {
    return Center(
        child: RaisedButton(
            child: Text('Show snackbar'),
            onPressed: () {
              Scaffold.of(context).showSnackBar(SnackBar(
                  content: Text("sagar"),
                  action: SnackBarAction(
                    label: 'UNDO',
                    onPressed: Scaffold.of(context).hideCurrentSnackBar,
                  )));
            }));
  }
}