mobile-app/lib/presentation/screens/qr_scan/qr_scan_page.dart

import 'dart:io';

import 'package:farm_tpf/presentation/custom_widgets/app_bar_widget.dart';
import 'package:flutter/material.dart';
import 'package:get/get.dart';
import 'package:qr_code_scanner/qr_code_scanner.dart';

class QrCodeScannerScreen extends StatefulWidget {
  @override
  State<StatefulWidget> createState() => _QrCodeScannerScreenState();
}

class _QrCodeScannerScreenState extends State<QrCodeScannerScreen> {
  // Barcode? result;
  QRViewController controller;
  final GlobalKey qrKey = GlobalKey(debugLabel: 'QR');

  // In order to get hot reload to work we need to pause the camera if the platform
  // is android, or resume the camera if the platform is iOS.
  @override
  void reassemble() {
    super.reassemble();
    if (Platform.isAndroid) {
      controller.pauseCamera();
    }
    controller.resumeCamera();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBarWidget(
        isBack: true,
      ),
      body: Column(
        children: <Widget>[
          Expanded(flex: 4, child: _buildQrView(context)),
        ],
      ),
    );
  }

  Widget _buildQrView(BuildContext context) {
    // For this example we check how width or tall the device is and change the scanArea and overlay accordingly.
    var scanArea = (MediaQuery.of(context).size.width < 400 || MediaQuery.of(context).size.height < 400) ? 150.0 : 300.0;
    // To ensure the Scanner view is properly sizes after rotation
    // we need to listen for Flutter SizeChanged notification and update controller
    return QRView(
      key: qrKey,
      onQRViewCreated: _onQRViewCreated,
      overlay: QrScannerOverlayShape(borderColor: Colors.red, borderRadius: 10, borderLength: 30, borderWidth: 10, cutOutSize: scanArea),
    );
  }

  void _onQRViewCreated(QRViewController controller) {
    setState(() {
      this.controller = controller;
    });
    controller.scannedDataStream.listen((scanData) {
      if (scanData != null) {
        Get.back(result: scanData);
      }
    });
  }

  void _onPermissionSet(BuildContext context, QRViewController ctrl, bool p) {
    if (!p) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('no Permission')),
      );
    }
  }

  @override
  void dispose() {
    controller?.dispose();
    super.dispose();
  }
}