universal_barcode_scanner 1.0.0+1

Barcode and QR code scanner for Flutter, on Android, iOS, macOS, web and Windows, from one widget and one callback.

Universal Barcode Scanner

Barcode and QR code scanning for Flutter, on Android, iOS, macOS, web and Windows, from one entry point.

  

_{iOS and Android above, web and Windows below.}

Platforms

Platform	How it scans	Embedded view
Android	Native, Play Services Vision	Yes
iOS	Native, AVFoundation	Yes
macOS	Native, AVFoundation and Vision	No
Web	html5-qrcode in an iframe, bundled, no CDN call	No
Windows	html5-qrcode in a WebView2	No

Windows needs the WebView2 runtime, which ships with Windows 11 and with any recent Edge.

Linux is not supported, and the reason is worth stating because the obvious idea does not work. Reusing the webview approach would be the natural route, but no published Flutter webview grants a page access to the camera on Linux: desktop_webview_window never connects WebKitGTK's permission-request signal, and webview_cef implements no CefPermissionHandler. Both engines deny by default, so getUserMedia fails whatever the page does. The native route is no better, since camera_linux has been at 0.0.8 since 2023. That is also why no barcode package on pub.dev covers Linux, mobile_scanner included. On Linux the scanner says so rather than failing on a missing plugin.

Install

flutter pub add universal_barcode_scanner

Requires Flutter 3.27 or later.

Android

Camera permission goes in your own manifest, android/app/src/main/AndroidManifest.xml:

<uses-permission android:name="android.permission.CAMERA" />

iOS

A usage description goes in ios/Runner/Info.plist. iOS kills the app without it:

<key>NSCameraUsageDescription</key>
<string>Camera permission is required for barcode scanning.</string>

macOS

Two things, and the scanner fails silently without either. A usage description in macos/Runner/Info.plist:

<key>NSCameraUsageDescription</key>
<string>Camera permission is required for barcode scanning.</string>

And the camera entitlement in both macos/Runner/DebugProfile.entitlements and macos/Runner/Release.entitlements, since a macOS app is sandboxed:

<key>com.apple.security.device.camera</key>
<true/>

Requires macOS 10.15 or later.

Web

Browsers only hand out the camera on a secure origin, so the page must be served over HTTPS. localhost counts as secure during development.

Scan one code

Opens the scanner as a route and comes back with what it read, or null if the user backed out:

final String? code = await UniversalBarcodeScanner.scan(context);

Parameter	Default	Effect
lineColor	Color(0xFFFF6666)	Colour of the scan line. Android, iOS and macOS only.
cancelButtonText	'Cancel'	Label of the cancel button. Android, iOS and macOS only.
isShowFlashIcon	false	Whether the torch toggle is shown. Android and iOS only.
scanType	ScanType.barcode	What the scanner looks for.
cameraFace	CameraFace.back	Which camera to open.
scanFormat	ScanFormat.all	Symbologies to accept. Android, iOS and macOS only; web reads every format.
barcodeAppBar	null	App bar above the scanner. Without one, the camera fills the route.
scanDelay	null	Pause between two reads in continuous mode.
flip	false	Mirrors the preview, for a front camera.
child	null	Drawn over the scanner, for instance a manual entry field.

Keep scanning

Same route, but every code read is emitted instead of the first one closing it. The stream closes by itself when the route goes away, whichever way it goes:

final StreamSubscription<String> sub =
    UniversalBarcodeScanner.stream(context).listen((String code) {
  debugPrint(code);
});

stream takes the same parameters as scan.

Embed the camera

To put the camera inside your own layout rather than on its own route. Android and iOS only:

UniversalBarcodeScanner(
  continuous: true,
  onScanned: (String code) => debugPrint(code),
  onBarcodeViewCreated: (BarcodeViewController controller) {
    this.controller = controller;
  },
);

The controller drives the running camera:

await controller.toggleFlash();
await controller.pauseScanning();
await controller.resumeScanning();

Parameter	Default	Effect
onBarcodeViewCreated	required	Called once the platform view exists.
onScanned	null	Called with every code read.
continuous	false	Whether reading continues after the first code.
scaleWidth, scaleHeight	null	Size of the view, or the constraints when null.
scanType, cameraFace, scanFormat, scanDelay, flip, child	see above	As in scan.

App bar

Passing a BarcodeAppBar is what makes the scanner show one at all:

UniversalBarcodeScanner.scan(
  context,
  barcodeAppBar: const BarcodeAppBar(
    appBarTitle: 'Scan',
    centerTitle: false,
    enableBackButton: true,
    backButtonIcon: Icon(Icons.arrow_back_ios),
  ),
);

The native namespace changed too, so the two packages can no longer be installed side by side in the same app. That was already true in practice: they declared the same Android package and the same iOS class, and the build failed on a duplicate.

Example

example/ is one app with the three ways to scan, one screen each.

cd example && flutter run

Tests

flutter test

Dependencies

webview_windows for the Windows scanner, path to resolve the bundled page next to the executable, and web for the iframe. Nothing on Android, iOS or macOS beyond the SDKs.

Credits

Derived from simple_barcode_scanner by Kunchok Tashi, which embeds the Android and iOS scanner of flutter_barcode_scanner by Amol Gangadhare. Both are MIT.

License

MIT, see LICENSE.