fis_lib_measure/lib/draw.dart

import 'package:flutter/material.dart';

class DrawRecord extends StatelessWidget {
  const DrawRecord({
    Key? key,
    required this.width,
    required this.height,
  }) : super(key: key);

  final double width;
  final double height;

  @override
  Widget build(BuildContext context) {
    return RepaintBoundary(
      child: CustomPaint(
        painter: _DrawRecordPainter(),
      ),
    );
  }
}

class _DrawRecordPainter extends CustomPainter {
  final pen = Paint()
    ..color = Colors.red
    ..isAntiAlias = true;

  @override
  void paint(Canvas canvas, Size size) {
    print("draw at ${DateTime.now()}");
    canvas.drawLine(
      Offset(100, 100),
      Offset(200, 200),
      pen,
    );
  }

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