custom_clipper_midline_semi_circle_ticket.dart

import 'package:flutter/material.dart';

const Color darkBlue = Color.fromARGB(255, 18, 32, 47);

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData.dark().copyWith(
        scaffoldBackgroundColor: darkBlue,
      ),
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        body: Center(
          child: MyWidget(),
        ),
      ),
    );
  }
}

class MyWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return const Scaffold(
      backgroundColor: Colors.black,
      body: Center(
        child: Ticket()
      )
    );
  }
}

class Ticket extends StatelessWidget {
  const Ticket({super.key});

  @override
  Widget build(BuildContext context) {
    double radius = 20;

    return ClipPath(
      clipper: const SemiCircleClipper(),
      child: Container(
        decoration: BoxDecoration(
          color: Colors.white,
          borderRadius: BorderRadius.circular(radius),
        ),
        constraints: const BoxConstraints.tightFor(
          width: 150,
          height: 150,
        ),
        child: const Center(
          child: Text(
            "%",
            style: TextStyle(
              fontSize: 80,
              fontWeight: FontWeight.bold,
              color: Colors.black,
            ),
          ),
        ),
      ),
    );
  }
}

class SemiCircleClipper extends CustomClipper<Path> {
  const SemiCircleClipper();

  @override
  Path getClip(Size size) {
    Path path = Path();
    path.lineTo(0, size.height * 0.4);
    path.quadraticBezierTo(
      size.width * 0.15,
      size.height * .5,
      0,
      size.height * 0.6,
    );
    path.lineTo(0, size.height);
    path.lineTo(size.width, size.height);
    path.lineTo(size.width, size.height * 0.6);
    path.quadraticBezierTo(
      size.width * 0.85,
      size.height * .5,
      size.width,
      size.height * .4,
    );
    path.lineTo(size.width, 0);
    path.close();

    return path;
  }

  @override
  bool shouldReclip(covariant SemiCircleClipper oldClipper) => false;
}