How to do it...

We need to start this recipe by first creating a shell that that will hold the CustomPainter  subclass:

1. Update the Star class to use a CustomPaint widget:

import 'package:flutter/material.dart';

class Star extends StatelessWidget {
  final Color color;
  final double size;

  const Star({
    Key key,
    this.color,
    this.size,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return SizedBox(
      width: size,
      height: size,
      child: CustomPaint(
        painter: _StarPainter(color),
      ),
    );
  }
}

2. This code will throw an error because the _StarPainter class doesn't exist yet. Create it now and make sure to override the required methods of CustomPainter:

class _StarPainter extends CustomPainter {
 final Color color;

 _StarPainter(this.color);

 @override
 void paint(Canvas canvas, Size size) {
 }

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

3.  Update the...