Mouse Pointer

main.dart

import 'package:flutter/material.dart';

final 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: SizedBox(
            height: 200,
            width: 100,
            child: CustomPaint(
              painter: MousePointerPainter(),
            ),
          ),
        ),
      ),
    );
  }
}

class MousePointerPainter extends CustomPainter {
  @override
  void paint(Canvas canvas, Size size) {
    final paint = Paint()
      ..color = Colors.white
      ..style = PaintingStyle.fill;

    final path = Path()
      ..moveTo(size.width / 2, 0)
      ..lineTo(size.width, size.height * .7)
      ..cubicTo(size.width, size.height * .7, size.width / 2, size.height, 0,
          size.height * .7)
      ..close();

    canvas.drawPath(path, paint);
  }

  @override
  bool shouldRepaint(MousePointerPainter oldDelegate) => true;
}