A Flutter plugin for scanning QR codes from image files. This plugin provides a simple interface to scan QR codes from images on both Android and iOS platforms.

Features

Scan QR codes from image files
Support for Android (using ZXing library)
Support for iOS (using AVFoundation/Core Image)
Returns structured results with error handling
Works with images from file picker or camera

Platform Support

Platform	Support
Android	✅
iOS	✅
Web	❌
macOS	❌
Windows	❌
Linux	❌

Installation

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

dependencies:
  ente_qr:
    path: path/to/ente_qr

Usage

Basic Usage

import 'package:ente_qr/ente_qr.dart';

final qr = EnteQr();

// Scan QR code from an image file
final result = await qr.scanQrFromImage('/path/to/image.jpg');

if (result.success) {
  print('QR Code content: ${result.content}');
} else {
  print('Error: ${result.error}');
}

Complete Example with File Picker

import 'package:flutter/material.dart';
import 'package:ente_qr/ente_qr.dart';
import 'package:file_picker/file_picker.dart';

class QrScannerPage extends StatefulWidget {
  @override
  _QrScannerPageState createState() => _QrScannerPageState();
}

class _QrScannerPageState extends State<QrScannerPage> {
  final _enteQr = EnteQr();
  String _result = 'No QR code scanned';

  Future<void> _scanQrFromImage() async {
    // Pick an image file
    FilePickerResult? fileResult = await FilePicker.platform.pickFiles(
      type: FileType.image,
      allowMultiple: false,
    );

    if (fileResult != null && fileResult.files.single.path != null) {
      final imagePath = fileResult.files.single.path!;
      
      // Scan QR code from the selected image
      final qrResult = await _enteQr.scanQrFromImage(imagePath);
      
      setState(() {
        if (qrResult.success) {
          _result = 'QR Code: ${qrResult.content}';
        } else {
          _result = 'Error: ${qrResult.error}';
        }
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('QR Scanner')),
      body: Column(
        children: [
          ElevatedButton(
            onPressed: _scanQrFromImage,
            child: Text('Pick Image and Scan QR'),
          ),
          Text(_result),
        ],
      ),
    );
  }
}

API Reference

EnteQr

The main class for QR code scanning operations.

Methods

`scanQrFromImage(String imagePath)`

Scans a QR code from an image file.

Parameters:

imagePath (String): The file path to the image containing the QR code

Returns:

Future<QrScanResult>: A result object containing either the QR code content or an error

QrScanResult

The result object returned by QR scanning operations.

Properties:

content (String?): The QR code content if successful, null otherwise
error (String?): Error message if scanning failed, null otherwise
success (bool): Whether the scanning operation was successful

Factory Constructors:

QrScanResult.success(String content): Creates a successful result
QrScanResult.error(String error): Creates an error result

Implementation Details

Android

The Android implementation uses the ZXing library (com.google.zxing) for QR code detection:

com.journeyapps:zxing-android-embedded:4.3.0
com.google.zxing:core:3.5.1

iOS

The iOS implementation uses Core Image framework's built-in QR code detection capabilities via CIDetector.

Error Handling

The plugin provides comprehensive error handling for common scenarios:

File not found
Invalid image format
No QR code found in image
Platform-specific errors
Unexpected errors

All errors are returned as part of the QrScanResult object with descriptive error messages.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is licensed under the same license as the Ente project.