curvepaint.dart

import 'package:flutter/material.dart';

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Drawing Paths',
      home: Container(
        color: Colors.white,
        child: CustomPaint(
          painter: CurvePainter(),
        ),
      ),
    );
  }
}

class CurvePainter extends CustomPainter {
  @override
  void paint(Canvas canvas, Size size) {
    var paint = Paint();
    paint.color = Colors.green[800];
    paint.style = PaintingStyle.fill;

    var path = Path();

    path.moveTo(0, size.height * 0.9167);
    path.quadraticBezierTo(size.width * 0.25, size.height * 0.875,
        size.width * 0.5, size.height * 0.9167);
    path.quadraticBezierTo(size.width * 0.75, size.height * 0.9584,
        size.width * 1.0, size.height * 0.9167);
    path.lineTo(size.width, size.height);
    path.lineTo(0, size.height);

    canvas.drawPath(path, paint);
  }

  @override
  bool shouldRepaint(CustomPainter oldDelegate) {
    return true;
  }
}