mobile-app/lib/presentation/screens/scan_qr/scan_qr_page.dart

import 'dart:io';

import 'package:farm_tpf/data/repository/repository.dart';
import 'package:flutter/material.dart';
import 'package:flutter/src/foundation/key.dart';
import 'package:flutter/src/widgets/framework.dart';
import 'package:get/get.dart';
import 'package:qr_code_scanner/qr_code_scanner.dart';

import '../../custom_widgets/widget_utils.dart';
import '../plot_detail/sc_plot_detail.dart';

class ScanQrPage extends StatefulWidget {
  const ScanQrPage({Key? key}) : super(key: key);

  @override
  State<ScanQrPage> createState() => _ScanQrPageState();
}

class _ScanQrPageState extends State<ScanQrPage> {
  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(
      body: SafeArea(
        child: Column(
          children: <Widget>[
            Expanded(flex: 4, child: _buildQrView(context)),
            Expanded(
              flex: 1,
              child: FittedBox(
                fit: BoxFit.contain,
                child: Column(
                  mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                  children: <Widget>[
                    if (result != null) Text('Barcode Type') else const Text('Scan a code'),
                    Row(
                      mainAxisAlignment: MainAxisAlignment.center,
                      crossAxisAlignment: CrossAxisAlignment.center,
                      children: <Widget>[
                        Container(
                          margin: const EdgeInsets.all(8),
                          child: ElevatedButton(
                              onPressed: () async {
                                await controller?.toggleFlash();
                                setState(() {});
                              },
                              child: FutureBuilder(
                                future: controller?.getFlashStatus(),
                                builder: (context, snapshot) {
                                  return Text('Flash: ${snapshot.data}');
                                },
                              )),
                        ),
                        Container(
                          margin: const EdgeInsets.all(8),
                          child: ElevatedButton(
                              onPressed: () async {
                                await controller?.flipCamera();
                                setState(() {});
                              },
                              child: FutureBuilder(
                                future: controller?.getCameraInfo(),
                                builder: (context, snapshot) {
                                  if (snapshot.data != null) {
                                    return Text('Camera facing ');
                                  } else {
                                    return const Text('loading');
                                  }
                                },
                              )),
                        )
                      ],
                    ),
                    Row(
                      mainAxisAlignment: MainAxisAlignment.center,
                      crossAxisAlignment: CrossAxisAlignment.center,
                      children: <Widget>[
                        Container(
                          margin: const EdgeInsets.all(8),
                          child: ElevatedButton(
                            onPressed: () async {
                              await controller?.pauseCamera();
                            },
                            child: const Text('pause', style: TextStyle(fontSize: 20)),
                          ),
                        ),
                        Container(
                          margin: const EdgeInsets.all(8),
                          child: ElevatedButton(
                            onPressed: () async {
                              await controller?.resumeCamera();
                            },
                            child: const Text('resume', style: TextStyle(fontSize: 20)),
                          ),
                        )
                      ],
                    ),
                  ],
                ),
              ),
            )
          ],
        ),
      ),
    );
  }

  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),
      onPermissionSet: (ctrl, p) => _onPermissionSet(context, ctrl, p),
    );
  }

  void _onQRViewCreated(QRViewController controller) {
    setState(() {
      this.controller = controller;
    });
    controller.scannedDataStream.listen((scanData) {
      setState(() {
        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();
  }
}