spectacular_barcode 0.0.2

A flutter plugin to check barcode and qrcode magnificantly

spectacular_barcode

A Flutter barcode and QR code scanner built with MethodChannel and native code:

• Android — CameraX + ML Kit (Kotlin)
• iOS — AVFoundation + Vision (Swift)

Includes a live camera preview, scan-window overlay, torch, zoom, and camera switching.

Features

• Live camera preview via Flutter texture
• Barcode / QR detection on device
• Visible scan area (cutout overlay)
• Torch toggle and zoom
• Front / back camera switch
• Same Dart API on Android and iOS

Supported platforms

Platform	Status
Android	Supported (minSdk 24)
iOS	Supported (iOS 13+)

Installation

Add the dependency to your pubspec.yaml:

dependencies:
  spectacular_barcode:
    path: ../spectacular_barcode   # or git / pub.dev when published

Then run:

flutter pub get

Permissions

Android

The plugin declares the camera permission. Ensure your app merges it (already included by the plugin):

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

Runtime permission is requested when the scanner starts.

iOS

Add to ios/Runner/Info.plist:

<key>NSCameraUsageDescription</key>
<string>Camera access is required to scan barcodes and QR codes.</string>

Quick start

import 'package:flutter/material.dart';
import 'package:spectacular_barcode/spectacular_barcode.dart';

class ScannerPage extends StatefulWidget {
  const ScannerPage({super.key});

  @override
  State<ScannerPage> createState() => _ScannerPageState();
}

class _ScannerPageState extends State<ScannerPage> {
  final _controller = SpectacularBarcodeController();
  String? _value;

  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SpectacularBarcodeView(
        controller: _controller,
        onDetect: (capture) {
          if (capture.barcodes.isEmpty) return;
          setState(() {
            _value = capture.barcodes.first.rawValue;
          });
          _controller.stop();
        },
      ),
      bottomNavigationBar: SafeArea(
        child: Padding(
          padding: const EdgeInsets.all(16),
          child: Text(_value ?? 'Scan a barcode'),
        ),
      ),
    );
  }
}

Scan window overlay

Pass a scanWindow to limit detection and show a framed cutout:

LayoutBuilder(
  builder: (context, constraints) {
    final size = constraints.biggest;
    final side = size.width * 0.72;
    final scanWindow = Rect.fromCenter(
      center: size.center(Offset.zero),
      width: side,
      height: side,
    );

    return SpectacularBarcodeView(
      controller: controller,
      scanWindow: scanWindow,
      overlayBuilder: (context, constraints) {
        return ScanWindowOverlay(
          controller: controller,
          scanWindow: scanWindow,
        );
      },
      onDetect: (capture) {
        // handle result
      },
    );
  },
);

Controller API

Method	Description
start()	Request permission and start the camera
stop()	Stop the camera
pause()	Pause the camera
toggleTorch()	Toggle flashlight
setZoomScale(double)	Zoom between 0.0 and 1.0
resetZoomScale()	Reset zoom
switchCamera()	Switch front / back
barcodes	Stream of BarcodeCapture events

Example app

cd example
flutter pub get
flutter run

The example shows a full-screen scanner with a scan area, then displays the scanned value with Copy and Scan again.

Architecture

Flutter talks to native code over MethodChannel / EventChannel:

• Method: com.zequetech.spectacular_barcode/scanner/method
• Event: com.zequetech.spectacular_barcode/scanner/event

Methods: state, request, start, stop, pause, toggleTorch, setScale, resetScale, updateScanWindow

License

MIT License. See LICENSE.