import 'dart:ui' as ui;
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'dart:typed_data';
import 'dart:io';
import 'dart:ui' as ui;
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'dart:typed_data';
import 'dart:io';
import 'package:path_provider/path_provider.dart';

class DrawScreen extends StatefulWidget {
  @override
  _DrawScreenState createState() => _DrawScreenState();
}

class _DrawScreenState extends State<DrawScreen> {
  GlobalKey _globalKey = GlobalKey();
  bool _imageSaved = false;

  Future<Uint8List?> _capturePng() async {
    try {
      RenderRepaintBoundary? boundary =
      _globalKey.currentContext!.findRenderObject() as RenderRepaintBoundary?;
      ui.Image image = await boundary!.toImage();
      ByteData? byteData =
      await image.toByteData(format: ui.ImageByteFormat.png);
      Uint8List pngBytes = byteData!.buffer.asUint8List();
      return pngBytes;
    } catch (e) {
      print(e);
      return null;
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Draw and Save'),
      ),
      body: Column(
        children: [
          Expanded(
            child: RepaintBoundary(
              key: _globalKey,
              child: CustomPaint(
                painter: MyPainter(),
              ),
            ),
          ),
          FilledButton(
            child: Text('Save'),
            onPressed: () async {
              Uint8List? pngBytes = await _capturePng();
              if (pngBytes != null) {
                String path =
                    '${(await getApplicationDocumentsDirectory()).path}/example.png';
                await File(path).writeAsBytes(pngBytes);
                setState(() {
                  _imageSaved = true;
                });
              }
            },
          ),
          if (_imageSaved) Text('Image saved successfully!'),
        ],
      ),
    );
  }
}

class MyPainter extends CustomPainter {
  @override
  void paint(Canvas canvas, Size size) {
    Paint paint = Paint()
      ..color = Colors.red
      ..strokeWidth = 2
      ..style = PaintingStyle.stroke;

    canvas.drawCircle(Offset(size.width / 2, size.height / 2), 50, paint);
  }

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