title: I'm trying to draw a custom shape in flutter, but unfortunately the shape doesn't appear, I just see the white container
body: <p>this is the custom shape code</p>
  <pre><code>class SignInPageCustomShape extends CustomPainter {
    @override
    void paint(Canvas canvas, Size size) {
      final paint = Paint();
      final Color myColor = Colors.black12;
      paint.color = myColor;
      paint.style = PaintingStyle.fill;
      final 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;
    }
  }
  </code></pre>
  <p>and this is my widget tree,I don't know what is wrong, I tried to put my container in different places, but the same result is gotten, stack overflow is asking me to explain more, but I haven't anything else to explain .</p>
  <pre><code>class Paint extends StatelessWidget {
    @override
    Widget build(BuildContext context) {
      return MaterialApp(
        home: Scaffold(
          body: Container(
            color: Colors.white,
            child: CustomPaint(
              painter: SignInPageCustomShape(),
            ),
          ),
        ),
      );
    }
  }
  </code></pre>