### Flutter QR Code Scanner Setup and Event Handling

Source: https://github.com/vespr-wallet/qr_code_scanner_plus/blob/master/example/README.md

This code snippet illustrates the configuration of a QR code scanner using `QRView` in Flutter. It demonstrates setting camera facing, defining allowed barcode formats, customizing the scanner overlay, initializing the QR view controller, listening for scanned data, and properly disposing of the controller to prevent memory leaks.

```Dart
      // You can choose between CameraFacing.front or CameraFacing.back. Defaults to CameraFacing.back
      // cameraFacing: CameraFacing.front,
      onQRViewCreated: _onQRViewCreated,
      // Choose formats you want to scan. Defaults to all formats.
      // formatsAllowed: [BarcodeFormat.qrcode],
      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) {
      setState(() {
        result = scanData;
      });
    });
  }

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

--------------------------------

### Configure Android Gradle and Kotlin Versions for QR Scanner Plus

Source: https://github.com/vespr-wallet/qr_code_scanner_plus/blob/master/README.md

This snippet provides the necessary updates to `ext.kotlin_version` and `classpath 'com.android.tools.build:gradle'` in `android/build.gradle`, along with the `distributionUrl` in `android/gradle/wrapper/gradle-wrapper.properties`, to ensure compatibility with the `qr_code_scanner_plus` plugin.

```Gradle
// In android/build.gradle
ext.kotlin_version = '1.5.10'
classpath 'com.android.tools.build:gradle:4.2.0'

// In android/gradle/wrapper/gradle-wrapper.properties
distributionUrl=https\://services.gradle.org/distributions/gradle-6.9-all.zip
```

--------------------------------

### Integrate jsQR Library for Web Scanning

Source: https://github.com/vespr-wallet/qr_code_scanner_plus/blob/master/README.md

Includes the `jsQR` library via CDN in `web/index.html` to enable QR code scanning on web platforms. Note that on web, only QR codes are supported, and advanced features like flash, pause, or resume are not yet implemented due to early platform view support in Flutter.

```HTML
<script src="https://cdn.jsdelivr.net/npm/jsqr@1.3.1/dist/jsQR.min.js"></script>
```

--------------------------------

### Configure iOS Info.plist for Camera Access

Source: https://github.com/vespr-wallet/qr_code_scanner_plus/blob/master/README.md

Adds necessary keys to `Info.plist` for camera usage description and embedded views preview, which are required for the `qr_code_scanner_plus` plugin to function correctly on iOS devices.

```XML
<key>io.flutter.embedded_views_preview</key>
<true/>
<key>NSCameraUsageDescription</key>
<string>This app needs camera access to scan QR codes</string>
```

--------------------------------

### Configure iOS Camera Usage and Background Modes for QR Code Scanner

Source: https://github.com/vespr-wallet/qr_code_scanner_plus/blob/master/example/README.md

This XML snippet for `info.plist` configures an iOS application to use the camera for QR code scanning and enables background fetch and remote notifications. The `NSCameraUsageDescription` key is crucial for requesting user permission to access the camera, providing a user-facing explanation for the access.

```XML
<dict>
    <key>io.flutter.embedded_views_preview</key>
	<true/>
	<key>UIBackgroundModes</key>
	<array>
		<string>fetch</string>
		<string>remote-notification</string>
	</array>
	<key>NSCameraUsageDescription</key>
    <string>Can we access your camera in order to scan barcodes?</string>
</dict>
```

--------------------------------

### Open iOS Project in Xcode for Asset Customization

Source: https://github.com/vespr-wallet/qr_code_scanner_plus/blob/master/example/ios/Runner/Assets.xcassets/LaunchImage.imageset/README.md

This method describes how to open the Xcode workspace for a Flutter project's iOS runner. Once opened, users can navigate to `Runner/Assets.xcassets` in the Project Navigator to replace or add desired launch screen images.

```Shell
open ios/Runner.xcworkspace
```

--------------------------------

### Set Android Minimum SDK Version for QR Scanner Plus

Source: https://github.com/vespr-wallet/qr_code_scanner_plus/blob/master/README.md

This snippet specifies the required update to the `minSdkVersion` in `android/app/build.gradle` to `20`, which is necessary for the `qr_code_scanner_plus` plugin to function correctly on Android devices.

```Gradle
// In android/app/build.gradle
defaultConfig{
  // ...
  minSdkVersion 20
}
```

--------------------------------

### Apply Android Dexing Artifact Transform Workaround

Source: https://github.com/vespr-wallet/qr_code_scanner_plus/blob/master/README.md

This snippet provides a workaround for a known `AbstractMethodError` bug in Flutter Beta or Dev channels (versions 1.25/1.26) by adding `android.enableDexingArtifactTransform=false` to your `gradle.properties` file, preventing issues with platform views.

```Gradle Properties
android.enableDexingArtifactTransform=false
```

--------------------------------

### Flutter QR Code Scanning with Camera Controls

Source: https://github.com/vespr-wallet/qr_code_scanner_plus/blob/master/example/README.md

This Dart code implements a Flutter application that utilizes the `qr_code_scanner` package to scan QR codes. It includes a `QRViewExample` StatefulWidget that manages the camera controller, displays scanned data, and provides buttons to toggle flash, flip the camera, and pause/resume the camera feed. The `reassemble` method handles camera state for hot reload on different platforms, and the scan area adjusts dynamically based on device dimensions.

```Dart
import 'dart:io';

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:qr_code_scanner/qr_code_scanner.dart';

void main() => runApp(MaterialApp(home: QRViewExample()));

class QRViewExample extends StatefulWidget {
  const QRViewExample({
    Key key,
  }) : super(key: key);

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

class _QRViewExampleState extends State<QRViewExample> {
  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: 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: ${describeEnum(result.format)}   Data: ${result.code}')
                  else
                    Text('Scan a code'),
                  Row(
                    mainAxisAlignment: MainAxisAlignment.center,
                    crossAxisAlignment: CrossAxisAlignment.center,
                    children: <Widget>[
                      Container(
                        margin: EdgeInsets.all(8),
                        child: RaisedButton(
                            onPressed: () async {
                              await controller?.toggleFlash();
                              setState(() {});
                            },
                            child: FutureBuilder(
                              future: controller?.getFlashStatus(),
                              builder: (context, snapshot) {
                                return Text('Flash: ${snapshot.data}');
                              },
                            )),
                      ),
                      Container(
                        margin: EdgeInsets.all(8),
                        child: RaisedButton(
                            onPressed: () async {
                              await controller?.flipCamera();
                              setState(() {});
                            },
                            child: FutureBuilder(
                              future: controller?.getCameraInfo(),
                              builder: (context, snapshot) {
                                if (snapshot.data != null) {
                                  return Text(
                                      'Camera facing ${describeEnum(snapshot.data)}');
                                } else {
                                  return Text('loading');
                                }
                              },
                            )),
                      )
                    ],
                  ),
                  Row(
                    mainAxisAlignment: MainAxisAlignment.center,
                    crossAxisAlignment: CrossAxisAlignment.center,
                    children: <Widget>[
                      Container(
                        margin: EdgeInsets.all(8),
                        child: RaisedButton(
                          onPressed: () async {
                            await controller?.pauseCamera();
                          },
                          child: Text('pause', style: TextStyle(fontSize: 20)),
                        ),
                      ),
                      Container(
                        margin: EdgeInsets.all(8),
                        child: RaisedButton(
                          onPressed: () async {
                            await controller?.resumeCamera();
                          },
                          child: 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,

```

--------------------------------

### Resume Camera Stream and Scanner in Flutter

Source: https://github.com/vespr-wallet/qr_code_scanner_plus/blob/master/README.md

Restarts the live camera stream and resumes the QR code scanning process after it has been previously paused, continuing scanning from where it left off.

```Dart
await controller.resumeCamera();
```

--------------------------------

### Scan and Display QR Code Data in Flutter

Source: https://github.com/vespr-wallet/qr_code_scanner_plus/blob/master/README.md

This Dart snippet demonstrates how to integrate the `QRView` widget into a Flutter application to capture and display QR code data. It shows how to initialize the scanner, listen to the `scannedDataStream` for `Barcode` results (including code and format), and manage camera state for hot reload on Android and iOS platforms.

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

  // 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();
    } else if (Platform.isIOS) {
      controller!.resumeCamera();
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Column(
        children: <Widget>[
          Expanded(
            flex: 5,
            child: QRView(
              key: qrKey,
              onQRViewCreated: _onQRViewCreated,
            ),
          ),
          Expanded(
            flex: 1,
            child: Center(
              child: (result != null)
                  ? Text(
                      'Barcode Type: ${describeEnum(result!.format)}   Data: ${result!.code}')
                  : Text('Scan a code'),
            ),
          )
        ],
      ),
    );
  }

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

--------------------------------

### Flip Camera (Back/Front) in Flutter

Source: https://github.com/vespr-wallet/qr_code_scanner_plus/blob/master/README.md

Toggles between the front and back cameras using the `controller.flipCamera()` method. The back camera is set as the default camera when the scanner is initialized.

```Dart
await controller.flipCamera();
```

--------------------------------

### Register Service Worker for Flutter Applications

Source: https://github.com/vespr-wallet/qr_code_scanner_plus/blob/master/example/web/index.html

This snippet checks for service worker support in the browser and, if available, registers 'flutter_service_worker.js' once the 'flutter-first-frame' event is fired. This is crucial for enabling offline capabilities and background processing in Flutter web applications.

```JavaScript
if ('serviceWorker' in navigator) { window.addEventListener('flutter-first-frame', function () { navigator.serviceWorker.register('flutter_service_worker.js'); }); }
```

--------------------------------

### Pause Camera Stream and Scanner in Flutter

Source: https://github.com/vespr-wallet/qr_code_scanner_plus/blob/master/README.md

Halts the live camera stream and pauses the QR code scanning process, allowing temporary suspension of scanning activities.

```Dart
await controller.pauseCamera();
```

--------------------------------

### Toggle Camera Flash (On/Off) in Flutter

Source: https://github.com/vespr-wallet/qr_code_scanner_plus/blob/master/README.md

Controls the camera flash state (on or off) using the `controller.toggleFlash()` method. By default, the camera flash is initially turned off.

```Dart
await controller.toggleFlash();
```

=== COMPLETE CONTENT === This response contains all available snippets from this library. No additional content exists. Do not make further requests.