ERP-APP-INVENTORY/lib/views/qr_view.dart

import 'dart:io';
import 'dart:ui' show ImageFilter;

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:get/get.dart';
import 'package:qr_code_scanner_plus/qr_code_scanner_plus.dart';
import 'package:inventory_app/constants.dart';

class QRViewExample extends StatefulWidget {
  const QRViewExample({super.key});

  @override
  State<StatefulWidget> createState() => _QRViewExampleState();
}

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

  @override
  void reassemble() {
    super.reassemble();
    if (Platform.isAndroid) {
      controller!.pauseCamera();
    }
    controller!.resumeCamera();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Column(
        children: <Widget>[
          Expanded(flex: 4, child: _buildQrView(context)),
          Expanded(
            flex: 1,
            child: Padding(
              padding: const EdgeInsets.symmetric(horizontal: 16.0, vertical: 12),
              child: ClipRRect(
                borderRadius: BorderRadius.circular(20),
                child: BackdropFilter(
                  filter: ImageFilter.blur(sigmaX: 12, sigmaY: 12),
                  child: Container(
                    decoration: BoxDecoration(
                      gradient: LinearGradient(
                        colors: [
                          Colors.white.withOpacity(0.08),
                          Colors.white.withOpacity(0.04),
                        ],
                        begin: Alignment.topLeft,
                        end: Alignment.bottomRight,
                      ),
                      borderRadius: BorderRadius.circular(20),
                      border: Border.all(color: Colors.white.withOpacity(0.12)),
                      boxShadow: [
                        BoxShadow(
                          color: Colors.black.withOpacity(0.15),
                          blurRadius: 10,
                          offset: const Offset(0, 4),
                        ),
                      ],
                    ),
                    child: FittedBox(
                      fit: BoxFit.contain,
                      child: Column(
                        mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                        children: <Widget>[
                          if (result != null)
                            Text(
                              'Barcode Type: ${describeEnum(result!.format)}   Data: ${result!.code}',
                              style: kTextFormFieldStyle(),
                            )
                          else
                            Text('Scan a code', style: kTextFormFieldStyle()),
                          Row(
                            mainAxisAlignment: MainAxisAlignment.center,
                            children: <Widget>[
                              _glassButton(
                                child: FutureBuilder(
                                  future: controller?.getFlashStatus(),
                                  builder: (context, snapshot) =>
                                      Text('Flash: ${snapshot.data}'),
                                ),
                                onPressed: () async {
                                  await controller?.toggleFlash();
                                  setState(() {});
                                },
                              ),
                              _glassButton(
                                child: FutureBuilder(
                                  future: controller?.getCameraInfo(),
                                  builder: (context, snapshot) =>
                                      snapshot.data != null
                                          ? Text('Camera facing ${describeEnum(snapshot.data!)}')
                                          : const Text('loading'),
                                ),
                                onPressed: () async {
                                  await controller?.flipCamera();
                                  setState(() {});
                                },
                              ),
                            ],
                          ),
                          Row(
                            mainAxisAlignment: MainAxisAlignment.center,
                            children: <Widget>[
                              _glassButton(
                                child: const Text('pause', style: TextStyle(fontSize: 20)),
                                onPressed: () async => controller?.pauseCamera(),
                              ),
                              _glassButton(
                                child: const Text('resume', style: TextStyle(fontSize: 20)),
                                onPressed: () async => controller?.resumeCamera(),
                              ),
                            ],
                          ),
                        ],
                      ),
                    ),
                  ),
                ),
              ),
            ),
          ),
        ],
      ),
    );
  }

  Widget _glassButton({required Widget child, required VoidCallback onPressed}) {
    return Container(
      margin: const EdgeInsets.all(8),
      child: ElevatedButton(
        style: ElevatedButton.styleFrom(
          elevation: 0,
          padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
          backgroundColor: Colors.white.withOpacity(0.06),
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(12),
            side: BorderSide(color: Colors.white.withOpacity(0.12)),
          ),
        ),
        onPressed: onPressed,
        child: child,
      ),
    );
  }

  Widget _buildQrView(BuildContext context) {
    final scanArea =
        (MediaQuery.of(context).size.width < 500 ||
            MediaQuery.of(context).size.height < 500)
        ? 300.0
        : 450.0;
    return QRView(
      key: qrKey,
      onQRViewCreated: _onQRViewCreated,
      overlay: QrScannerOverlayShape(
        borderColor: Colors.blue,
        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);
      Get.back(result: result!.code);
    });
  }

  void _onPermissionSet(BuildContext context, QRViewController ctrl, bool p) {
    if (!p) Get.snackbar("Permission", 'no Permission');
  }
}