mobile_scanner

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)	:heavy_check_mark:	:heavy_check_mark:	:x:	:x:
returnImage	:heavy_check_mark:	:heavy_check_mark:	:x:	:x:
scanWindow	:heavy_check_mark:	:heavy_check_mark:	:x:	:x:
barcodeOverlay	:heavy_check_mark:	:heavy_check_mark:	:x:	:x:

Platform Support

Android	iOS	macOS	Web	Linux	Windows
✔	✔	✔	✔	:x:	:x:

Platform specific setup

Android

This package uses by default the bundled version of MLKit Barcode-scanning for Android. This version is immediately available to the device. But it will increase the size of the app by approximately 3 to 10 MB.

The alternative is to use the unbundled version of MLKit Barcode-scanning for Android. This version is downloaded on first use via Google Play Services. It increases the app size by around 600KB.

To use the unbundled version of the MLKit Barcode-scanning, add the following line to your /android/gradle.properties file:

dev.steenbakker.mobile_scanner.useUnbundled=true

iOS

Add the following keys to your Info.plist file, located in 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