QR Scanner Master #

Professional QR Code Scanner and Generator Plugin for Flutter with advanced features including real-time scanning, QR generation, barcode support, and comprehensive customization options.

Features #

This project is a starting point for a Flutter plug-in package, a specialized package that includes platform-specific implementation code for Android and/or iOS.7457457457

🎨 Professional QR Generation #

• High-quality QR code generation with customizable size
• Advanced styling options: colors, gradients, rounded corners
• Logo embedding in QR codes
• Error correction levels (Low, Medium, Quartile, High)
• Border and margin customization
• Export to file or get as bytes

📱 Platform Support #

• Android (API 21+) with CameraX and ML Kit
• iOS (12.0+) with AVFoundation and Vision framework
• Permission handling with user-friendly prompts
• Camera controls (flash, focus, resolution)

🛠️ Developer Experience #

• Comprehensive error handling with custom exceptions
• Type-safe APIs with detailed documentation
• Preset configurations for common use cases
• Extensive customization options
• Memory efficient image processing

Installation #

Add this to your package's pubspec.yaml file:

dependencies:
  qr_scanner_master: ^1.0.1

Then run:

flutter pub get

Platform Setup #

Android #

Add the following permissions to your android/app/src/main/AndroidManifest.xml:

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

iOS #

Add the following to your ios/Runner/Info.plist:

<key>NSCameraUsageDescription</key>
<string>This app needs camera access to scan QR codes and barcodes</string>
<key>NSPhotoLibraryUsageDescription</key>
<string>This app needs photo library access to scan QR codes from images</string>

Quick Start #

Basic QR Code Scanning #

import 'package:qr_scanner_master/qr_scanner_master.dart';

// Simple scan
final qrScanner = QrScannerMaster();
final result = await qrScanner.quickScan();
if (result != null) {
  print('Scanned: $result');
}

// Advanced scan with options
final scanResult = await qrScanner.scanWithCamera(
  ScanOptions(
    formats: [BarcodeFormat.qrCode],
    enableFlash: false,
    showOverlay: true,
    beepOnScan: true,
    vibrateOnScan: true,
  ),
);

if (scanResult != null) {
  print('Data: ${scanResult.data}');
  print('Format: ${scanResult.format}');
  print('Timestamp: ${scanResult.timestamp}');
}

QR Code Generation #

import 'package:qr_scanner_master/qr_scanner_master.dart';

final qrScanner = QrScannerMaster();

// Simple generation
final qrBytes = await qrScanner.quickGenerate('https://flutter.cn');

// Advanced generation with styling
final styledQrBytes = await qrScanner.generateQrCode(
  'https://flutter.cn',
  QrGenerationOptions(
    size: 512,
    foregroundColor: Color(0xFF2196F3),
    backgroundColor: Color(0xFFFFFFFF),
    errorCorrectionLevel: ErrorCorrectionLevel.high,
    margin: 20,
    roundedCorners: true,
    cornerRadius: 8.0,
  ),
);

// Display in your app
Image.memory(styledQrBytes)

// Or save to file
await qrScanner.generateQrCodeToFile(
  'https://flutter.cn',
  '/path/to/qr_code.png',
);

Scanning from Images #

// Scan from file path
final results = await qrScanner.scanFromImageFile('/path/to/image.jpg');

// Scan from File object
final file = File('/path/to/image.jpg');
final results = await qrScanner.scanFromFile(file);

// Scan from bytes
final imageBytes = await file.readAsBytes();
final results = await qrScanner.scanFromBytes(imageBytes);

for (final result in results) {
  print('Found: ${result.data}');
}

Advanced Usage #

Custom Scan Options #

final result = await qrScanner.scanWithCamera(
  ScanOptions(
    formats: [BarcodeFormat.qrCode, BarcodeFormat.ean13],
    enableFlash: true,
    autoFocus: true,
    multiScan: true,
    maxScans: 5,
    beepOnScan: true,
    vibrateOnScan: true,
    showOverlay: true,
    overlayColor: 0xFF00FF00,
    restrictScanArea: true,
    scanAreaRatio: 0.8,
    timeoutSeconds: 30,
    cameraResolution: CameraResolution.high,
    cameraFacing: CameraFacing.back,
  ),
);

Advanced QR Generation #

final qrBytes = await qrScanner.generateQrCode(
  'https://flutter.cn',
  QrGenerationOptions(
    size: 1024,
    errorCorrectionLevel: ErrorCorrectionLevel.high,
    foregroundColor: Color(0xFF000000),
    backgroundColor: Color(0xFFFFFFFF),
    margin: 40,

    // Add logo
    logoData: logoImageBytes,
    logoSizeRatio: 0.2,

    // Styling
    roundedCorners: true,
    cornerRadius: 12.0,

    // Gradient colors
    gradientColors: [Color(0xFF2196F3), Color(0xFF21CBF3)],
    gradientDirection: 0.5, // Diagonal

    // Border
    addBorder: true,
    borderWidth: 4,
    borderColor: Color(0xFF333333),
  ),
);

Permission Handling #

// Check permissions
final hasPermission = await qrScanner.hasCameraPermission();

// Request permissions
final granted = await qrScanner.requestCameraPermission();

if (!granted) {
  // Handle permission denied
  print('Camera permission is required for scanning');
}

Camera Controls #

// Get available cameras
final cameras = await qrScanner.getAvailableCameras();

// Check flash availability
final hasFlash = await qrScanner.hasFlash();

// Toggle flash
await qrScanner.toggleFlash(true);

// Scanner controls
await qrScanner.pauseScanner();
await qrScanner.resumeScanner();
await qrScanner.stopScanner();

Preset Configurations #

The plugin includes several preset configurations for common use cases:

Scan Presets #

// QR codes only
await qrScanner.scanWithCamera(ScanPresets.qrOnly);

// All supported formats
await qrScanner.scanWithCamera(ScanPresets.allFormats);

// Fast scanning
await qrScanner.scanWithCamera(ScanPresets.fastScan);

// High quality scanning
await qrScanner.scanWithCamera(ScanPresets.highQuality);

// Multiple codes
await qrScanner.scanWithCamera(ScanPresets.multiScan);

// Silent scanning (no sound/vibration)
await qrScanner.scanWithCamera(ScanPresets.silent);

Generation Presets #

// Standard QR code
await qrScanner.generateQrCode(data, QrGenerationPresets.standard);

// High quality for printing
await qrScanner.generateQrCode(data, QrGenerationPresets.highQuality);

// Colorful with rounded corners
await qrScanner.generateQrCode(data, QrGenerationPresets.colorful);

// Minimal size
await qrScanner.generateQrCode(data, QrGenerationPresets.minimal);

// With border
await qrScanner.generateQrCode(data, QrGenerationPresets.withBorder);

Supported Barcode Formats #

• QR Code
• EAN-8, EAN-13
• Code 39, Code 93, Code 128
• Codabar
• ITF (Interleaved 2 of 5)
• UPC-A, UPC-E
• Data Matrix
• Aztec
• PDF417
• RSS-14, RSS-Expanded

Error Handling #

The plugin provides comprehensive error handling with custom exceptions:

try {
  final result = await qrScanner.scanWithCamera();
} on QrScannerException catch (e) {
  switch (e.message) {
    case 'Camera permission denied':
      // Handle permission error
      break;
    case 'Camera error':
      // Handle camera error
      break;
    case 'Scan was cancelled by user':
      // Handle cancellation
      break;
    default:
      // Handle other errors
      break;
  }
} catch (e) {
  // Handle unexpected errors
  print('Unexpected error: $e');
}

Performance Tips #

1. Use appropriate scan options: Limit formats and scan area for better performance
2. Handle permissions early: Check and request permissions before scanning
3. Optimize image size: For image scanning, use appropriately sized images
4. Use presets: Leverage built-in presets for common scenarios
5. Clean up resources: Stop scanner when not needed

Example App #

The plugin includes a comprehensive example app demonstrating all features. To run it:

cd example
flutter run

Contributing #

Contributions are welcome! Please read our contributing guidelines and submit pull requests to our repository.