fast_barcode_scanner

Fast barcode & QR code scanning library using the latest technologies on Android and iOS.

ML Kit and CameraX on Android
AVFoundation and Vision on iOS.

It provides a live preview widget you can put anywhere in your widget tree with rich configurability.

Installation

This plugin required iOS 11.0 and Android API level 21 or higher.

Add the following line to your pubspec.yaml:

fast_barcode_scanner: ^2.0.0-dev.2

iOS

Add the NSCameraUsageDescription key to your ios/Runner/Info.plist, like so:

<key>NSCameraUsageDescription</key>
<string>This app requires access to your phone’s camera solely for scanning barcodes or QR codes</string>

Android

Change the minimum Android api level to 21 (or higher) in your android/app/build.gradle file.

minSdkVersion 21

Usage

Insert the BarcodeCamera anywhere in your widget tree to get a live camera preview:

import 'package:fast_barcode_scanner/fast_barcode_scanner.dart';

class MyScannerScreen extends StatelessWidget {
    @override
    Widget build(BuildContext context) {
        return Scaffold(
            appBar: AppBar(title: Text('Barcode and QR code Scanner')),
            body: BarcodeCamera(
                types: const [
                    BarcodeType.ean8,
                    BarcodeType.ean13,
                    BarcodeType.code128,
                    BarcodeType.qr
                ],
                resolution: Resolution.hd720,
                framerate: Framerate.fps30,
                position: CameraPosition.back,
                mode: DetectionMode.pauseVideo,
                onScan: (code) => print(code),
                children: [
                    MaterialPreviewOverlay(animateDetection: false),
                    BlurPreviewOverlay(),
                    Positioned(
                      child: ElevatedButton(
                        onPressed: () =>
                            CameraController.instance.resumeDetector(),
                        child: Text('Resume'),
                      ),
                    )
                ],
            )
        )
    }
}

Two overlays are included:

MaterialPreviewOverlay mimics the official material barcode scanning example.
BlurPreviewOverlay blurs the screen when a barcode or QR code is detected.

Controlling the camera

The CameraController-singleton manages the camera. Normally when using BarcodeCamera you don't need CameraController.

To get access use the following anyhwere in your code:

final controller = CameraController()

Here is a full list of all the methods CameraController provides:

method	Description
`initialize`	Initializes the scanner with the provided config
`pauseDetector`	Actively pauses the scanner
`resumeDetector`	Resumes the scanner from the paused state
`toggleTorch`	toggles the torch on and off
`changeConfiguration`	Push an updated `ScannerConfiguration`
`analyzeImage`
`dispose`	Stops and resets the camera on platform level

CameraState

The state comes in handy when building overlays that change depending on it. You can access the state by using CameraController().state.

Attribute	Description
`isInitialized`	Indicated whether the camera is currently initialized
`previewConfig`	The current `PreviewConfiguration`
`scannerConfig`	The current `ScannerConfiguration`
`eventNotifier`	Notifies listeners of `CameraEvent`s
`torchState`	The current state of the torch (on/off)
`hasError`	Indicates if `error` is null or not
`error`	Access the most recent error