/mobile_scanner

A universal scanner for Flutter based on MLKit. Uses CameraX on Android and AVFoundation on iOS.

Primary LanguageDartBSD 3-Clause "New" or "Revised" LicenseBSD-3-Clause

mobile_scanner

pub package style: lint mobile_scanner GitHub Sponsors

A universal scanner for Flutter based on MLKit. Uses CameraX on Android and AVFoundation on iOS.

Features Supported

See the example app for detailed implementation information.

Features Android iOS macOS Web
analyzeImage (Gallery) ✔️ ✔️
returnImage ✔️ ✔️
scanWindow ✔️ ✔️
barcodeOverlay ✔️ ✔️

Platform Support

Android iOS macOS Web Linux Windows

Platform specific setup

Android

This packages uses the bundled version of MLKit Barcode-scanning for Android. This version is more accurate and immediately available to devices. However, this version will increase the size of the app with approximately 3 to 10 MB. The alternative for this is to use the unbundled version of MLKit Barcode-scanning for Android. This version is older than the bundled version however this only increases the size by around 600KB. To use this version you must alter the mobile_scanner gradle file to replace com.google.mlkit:barcode-scanning:17.0.2 with com.google.android.gms:play-services-mlkit-barcode-scanning:18.0.0. Keep in mind that if you alter the gradle files directly in your project it can be overriden when you update your pubspec.yaml. I am still searching for a way to properly replace the module in gradle but have yet to find one.

You can read more about the difference between the two versions here.

iOS

Add the following keys to your Info.plist file, located in /ios/Runner/Info.plist: NSCameraUsageDescription - describe why your app needs access to the camera. This is called Privacy - Camera Usage Description in the visual editor.

If you want to use the local gallery feature from image_picker NSPhotoLibraryUsageDescription - describe why your app needs permission for the photo library. This is called Privacy - Photo Library Usage Description in the visual editor.

Example,

<key>NSCameraUsageDescription</key>
<string>This app needs camera access to scan QR codes</string>

<key>NSPhotoLibraryUsageDescription</key>
<string>This app needs photos access to get QR code from photo library</string>

macOS

Ensure that you granted camera permission in XCode -> Signing & Capabilities:

Screenshot of XCode where Camera is checked

Web

This package uses ZXing on web to read barcodes so it needs to be included in index.html as script.

<script src="https://unpkg.com/@zxing/library@0.19.1" type="application/javascript"></script>

Usage

Import package:mobile_scanner/mobile_scanner.dart, and use the widget with or without the controller.

If you don't provide a controller, you can't control functions like the torch(flash) or switching camera.

If you don't set detectionSpeed to DetectionSpeed.noDuplicates, you can get multiple scans in a very short time, causing things like pop() to fire lots of times.

Example without controller:

import 'package:mobile_scanner/mobile_scanner.dart';

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Mobile Scanner')),
      body: MobileScanner(
        // fit: BoxFit.contain,
        onDetect: (capture) {
          final List<Barcode> barcodes = capture.barcodes;
          final Uint8List? image = capture.image;
          for (final barcode in barcodes) {
            debugPrint('Barcode found! ${barcode.rawValue}');
          }
        },
      ),
    );
  }

Example with controller and initial values:

import 'package:mobile_scanner/mobile_scanner.dart';

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Mobile Scanner')),
      body: MobileScanner(
        // fit: BoxFit.contain,
        controller: MobileScannerController(
          detectionSpeed: DetectionSpeed.normal,
          facing: CameraFacing.front,
          torchEnabled: true,
        ),
        onDetect: (capture) {
          final List<Barcode> barcodes = capture.barcodes;
          final Uint8List? image = capture.image;
          for (final barcode in barcodes) {
            debugPrint('Barcode found! ${barcode.rawValue}');
          }
        },
      ),
    );
  }

Example with controller and torch & camera controls:

import 'package:mobile_scanner/mobile_scanner.dart';

  MobileScannerController cameraController = MobileScannerController();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: const Text('Mobile Scanner'),
          actions: [
            IconButton(
              color: Colors.white,
              icon: ValueListenableBuilder(
                valueListenable: cameraController.torchState,
                builder: (context, state, child) {
                  switch (state as TorchState) {
                    case TorchState.off:
                      return const Icon(Icons.flash_off, color: Colors.grey);
                    case TorchState.on:
                      return const Icon(Icons.flash_on, color: Colors.yellow);
                  }
                },
              ),
              iconSize: 32.0,
              onPressed: () => cameraController.toggleTorch(),
            ),
            IconButton(
              color: Colors.white,
              icon: ValueListenableBuilder(
                valueListenable: cameraController.cameraFacingState,
                builder: (context, state, child) {
                  switch (state as CameraFacing) {
                    case CameraFacing.front:
                      return const Icon(Icons.camera_front);
                    case CameraFacing.back:
                      return const Icon(Icons.camera_rear);
                  }
                },
              ),
              iconSize: 32.0,
              onPressed: () => cameraController.switchCamera(),
            ),
          ],
        ),
        body: MobileScanner(
          // fit: BoxFit.contain,
          controller: cameraController,
          onDetect: (capture) {
            final List<Barcode> barcodes = capture.barcodes;
            final Uint8List? image = capture.image;
            for (final barcode in barcodes) {
              debugPrint('Barcode found! ${barcode.rawValue}');
            }
          },
        ),
    );
  }

Example with controller and returning images

import 'package:mobile_scanner/mobile_scanner.dart';

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Mobile Scanner')),
      body: MobileScanner(
        fit: BoxFit.contain,
        controller: MobileScannerController(
          // facing: CameraFacing.back,
          // torchEnabled: false,
          returnImage: true,
        ),
        onDetect: (capture) {
          final List<Barcode> barcodes = capture.barcodes;
          final Uint8List? image = capture.image;
          for (final barcode in barcodes) {
            debugPrint('Barcode found! ${barcode.rawValue}');
          }
          if (image != null) {
            showDialog(
              context: context,
              builder: (context) =>
                  Image(image: MemoryImage(image)),
            );
            Future.delayed(const Duration(seconds: 5), () {
              Navigator.pop(context);
            });
          }
        },
      ),
    );
  }

BarcodeCapture

The onDetect function returns a BarcodeCapture objects which contains the following items.

Property name Type Description
barcodes List A list with scanned barcodes.
image Uint8List? If enabled, an image of the scan.

You can use the following properties of the Barcode object.

Property name Type Description
format BarcodeFormat
rawBytes Uint8List? binary scan result
rawValue String? Value if barcode is in UTF-8 format
displayValue String?
type BarcodeType
calendarEvent CalendarEvent?
contactInfo ContactInfo?
driverLicense DriverLicense?
email Email?
geoPoint GeoPoint?
phone Phone?
sms SMS?
url UrlBookmark?
wifi WiFi? WiFi Access-Point details