qrbar 0.0.4

A lightweight Flutter package to scan and generate QR codes and barcodes with a clean and unified API.

example/lib/main.dart

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

void main() {
  runApp(const QRBarShowcase());
}

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

  @override
  State<QRBarShowcase> createState() => _QRBarShowcaseState();
}

class _QRBarShowcaseState extends State<QRBarShowcase> {
  // Display state
  int _currentIndex = 0;

  // Scanning result
  QrBarScanResult? _scanResult;
  bool _isScanning = false;

  // QR Style showcase
  QrStyle _currentStyle = QrStyle.standard;
  final String _demoUrl = 'https://flutter.dev';

  // Colors for styling
  Color _fgColor = Colors.black;
  Color _bgColor = Colors.white;
  Color _secondaryColor = Colors.blue;
  Color _tertiaryColor = Colors.red;

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData(
        colorSchemeSeed: Colors.deepPurple,
        useMaterial3: true,
      ),
      home: Scaffold(
        appBar: AppBar(
          title: const Text('QRBar Showcase'),
          elevation: 2,
        ),
        body: IndexedStack(
          index: _currentIndex,
          children: [
            _buildQRStylesShowcase(),
            _buildBarcodeTypesShowcase(),
            _buildScannerView(),
          ],
        ),
        bottomNavigationBar: BottomNavigationBar(
          currentIndex: _currentIndex,
          onTap: (index) => setState(() {
            _currentIndex = index;
            if (index != 2) {
              _isScanning = false; // Stop scanning when switching tabs
            }
          }),
          items: const [
            BottomNavigationBarItem(
              icon: Icon(Icons.qr_code),
              label: 'QR Styles',
            ),
            BottomNavigationBarItem(
              icon: Icon(Icons.view_list),
              label: 'Barcode Types',
            ),
            BottomNavigationBarItem(
              icon: Icon(Icons.qr_code_scanner),
              label: 'Scanner',
            ),
          ],
        ),
      ),
    );
  }

  // QR STYLES SHOWCASE
  Widget _buildQRStylesShowcase() {
    return Column(
      children: [
        // QR Style display
        Expanded(
          child: SingleChildScrollView(
            padding: const EdgeInsets.all(20),
            child: Column(
              children: [
                // Current Style Title
                Text(
                  _currentStyle.label,
                  style: const TextStyle(
                    fontSize: 22,
                    fontWeight: FontWeight.bold,
                  ),
                ),
                const SizedBox(height: 24),

                // QR Code Display
                QrBarGenView(
                  data: _demoUrl,
                  type: QrBarType.qr,
                  qrStyle: _currentStyle,
                  size: 250,
                  fg: _fgColor,
                  bg: _bgColor,
                  secondaryColor: _secondaryColor,
                  tertiaryColor: _tertiaryColor,
                ),

                const SizedBox(height: 20),

                // Save & Share buttons
                Row(
                  mainAxisAlignment: MainAxisAlignment.center,
                  children: [
                    ElevatedButton.icon(
                      onPressed: () => _saveCurrentQR(),
                      icon: const Icon(Icons.save),
                      label: const Text('Save'),
                    ),
                    const SizedBox(width: 16),
                    ElevatedButton.icon(
                      onPressed: () => _shareCurrentQR(),
                      icon: const Icon(Icons.share),
                      label: const Text('Share'),
                    ),
                  ],
                ),

                const SizedBox(height: 40),

                // Style selection
                const Text(
                  'Select Style:',
                  style: TextStyle(
                    fontSize: 18,
                    fontWeight: FontWeight.bold,
                  ),
                ),
                const SizedBox(height: 16),

                // Style grid
                Wrap(
                  spacing: 10,
                  runSpacing: 10,
                  alignment: WrapAlignment.center,
                  children: QrStyle.values.map((style) {
                    return InkWell(
                      onTap: () => setState(() => _currentStyle = style),
                      child: Container(
                        padding: const EdgeInsets.all(8),
                        decoration: BoxDecoration(
                          color: style == _currentStyle
                              ? Colors.deepPurple.withOpacity(0.1)
                              : Colors.transparent,
                          border: Border.all(
                            color: style == _currentStyle
                                ? Colors.deepPurple
                                : Colors.grey.shade300,
                            width: style == _currentStyle ? 2 : 1,
                          ),
                          borderRadius: BorderRadius.circular(8),
                        ),
                        child: Column(
                          children: [
                            SizedBox(
                              width: 80,
                              height: 80,
                              child: QrBarGenView(
                                data: 'demo',
                                type: QrBarType.qr,
                                qrStyle: style,
                                secondaryColor: _secondaryColor,
                                tertiaryColor: _tertiaryColor,
                              ),
                            ),
                            const SizedBox(height: 6),
                            Text(
                              style.label,
                              style: TextStyle(
                                fontWeight: style == _currentStyle
                                    ? FontWeight.bold
                                    : FontWeight.normal,
                              ),
                            ),
                          ],
                        ),
                      ),
                    );
                  }).toList(),
                ),

                const SizedBox(height: 20),

                // Color pickers
                Row(
                  mainAxisAlignment: MainAxisAlignment.center,
                  children: [
                    _buildColorPicker(
                        'FG', _fgColor, (c) => setState(() => _fgColor = c)),
                    const SizedBox(width: 16),
                    _buildColorPicker(
                        'BG', _bgColor, (c) => setState(() => _bgColor = c)),
                    const SizedBox(width: 16),
                    _buildColorPicker('2nd', _secondaryColor,
                        (c) => setState(() => _secondaryColor = c)),
                  ],
                ),
              ],
            ),
          ),
        ),
      ],
    );
  }

  // BARCODE TYPES SHOWCASE
  Widget _buildBarcodeTypesShowcase() {
    final barcodeData = {
      QrBarType.c128: 'ABC-12345-Z',
      QrBarType.ean13: '5901234123457',
      QrBarType.upc: '042100005264',
      QrBarType.pdf417: 'PDF417 Example',
      QrBarType.aztec: 'Aztec Code',
      QrBarType.dm: 'DataMatrix',
    };

    return ListView(
      padding: const EdgeInsets.all(16),
      children: [
        const Center(
          child: Text(
            'Supported Barcode Types',
            style: TextStyle(
              fontSize: 20,
              fontWeight: FontWeight.bold,
            ),
          ),
        ),
        const SizedBox(height: 20),

        // QR Code Card
        _buildBarcodeCard(
          'QR Code',
          'Two-dimensional matrix code',
          _demoUrl,
          QrBarType.qr,
        ),

        // Other barcode type cards
        ...barcodeData.entries.map((entry) => _buildBarcodeCard(
              entry.key.label,
              entry.key.toString().split('.').last.toUpperCase(),
              entry.value,
              entry.key,
            )),
      ],
    );
  }

  Widget _buildBarcodeCard(
      String title, String description, String data, QrBarType type) {
    return Card(
      margin: const EdgeInsets.only(bottom: 16),
      elevation: 2,
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          children: [
            Text(
              title,
              style: const TextStyle(
                fontSize: 18,
                fontWeight: FontWeight.bold,
              ),
            ),
            Text(description),
            const SizedBox(height: 16),
            QrBarGenView(
              data: data,
              type: type,
              size: 180,
            ),
            const SizedBox(height: 10),
            Text(
              'Data: $data',
              style: const TextStyle(fontFamily: 'monospace'),
            ),
            const SizedBox(height: 10),
            Row(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                ElevatedButton.icon(
                  onPressed: () => _saveBarcode(data, type),
                  icon: const Icon(Icons.save),
                  label: const Text('Save'),
                ),
                const SizedBox(width: 12),
                ElevatedButton.icon(
                  onPressed: () => _shareBarcode(data, type),
                  icon: const Icon(Icons.share),
                  label: const Text('Share'),
                ),
              ],
            ),
          ],
        ),
      ),
    );
  }

  // SCANNER VIEW
  Widget _buildScannerView() {
    return _isScanning ? _buildActiveScannerView() : _buildScanResultView();
  }

  Widget _buildActiveScannerView() {
    return Stack(
      children: [
        // Camera scanner
        QrBarScanView(
          onScan: (result) {
            setState(() {
              _scanResult = result;
              _isScanning = false;
            });
          },
        ),

        // Overlay with instructions
        SafeArea(
          child: Column(
            children: [
              Container(
                padding: const EdgeInsets.all(16),
                margin: const EdgeInsets.all(16),
                decoration: BoxDecoration(
                  color: Colors.black.withOpacity(0.7),
                  borderRadius: BorderRadius.circular(8),
                ),
                child: const Text(
                  'Point camera at any QR code or barcode',
                  style: TextStyle(color: Colors.white),
                  textAlign: TextAlign.center,
                ),
              ),
              const Spacer(),
              Container(
                color: Colors.black.withOpacity(0.5),
                width: double.infinity,
                padding: const EdgeInsets.all(16),
                child: TextButton.icon(
                  onPressed: () => setState(() => _isScanning = false),
                  icon: const Icon(Icons.close, color: Colors.white),
                  label: const Text(
                    'Cancel Scan',
                    style: TextStyle(color: Colors.white),
                  ),
                ),
              ),
            ],
          ),
        ),
      ],
    );
  }

  Widget _buildScanResultView() {
    return Padding(
      padding: const EdgeInsets.all(20),
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          if (_scanResult == null) ...[
            const Icon(
              Icons.qr_code_scanner,
              size: 80,
              color: Colors.grey,
            ),
            const SizedBox(height: 20),
            const Text(
              'No Code Scanned Yet',
              style: TextStyle(
                fontSize: 18,
                fontWeight: FontWeight.bold,
              ),
            ),
            const SizedBox(height: 10),
            const Text(
              'Tap the button below to start scanning',
              textAlign: TextAlign.center,
            ),
          ] else ...[
            // Show scan result
            const Text(
              'Scan Result',
              style: TextStyle(
                fontSize: 22,
                fontWeight: FontWeight.bold,
              ),
            ),
            const SizedBox(height: 20),

            // Display the scanned code
            QrBarGenView(
              data: _scanResult!.value,
              type: _scanResult!.type,
              size: 200,
            ),

            const SizedBox(height: 20),

            // Result information
            Card(
              elevation: 2,
              child: Padding(
                padding: const EdgeInsets.all(16),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    _buildResultRow('Type', _scanResult!.type.label),
                    const Divider(),
                    _buildResultRow('Content', _scanResult!.value),
                    const Divider(),
                    _buildResultRow('Time', _formatTime(_scanResult!.time)),
                  ],
                ),
              ),
            ),

            const SizedBox(height: 20),

            // Actions for the scan result
            Row(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                OutlinedButton.icon(
                  onPressed: () => _shareBarcode(
                    _scanResult!.value,
                    _scanResult!.type,
                  ),
                  icon: const Icon(Icons.share),
                  label: const Text('Share'),
                ),
              ],
            ),
          ],

          const Spacer(),

          // Scan button
          SizedBox(
            width: double.infinity,
            child: ElevatedButton.icon(
              onPressed: () => setState(() => _isScanning = true),
              icon: const Icon(Icons.qr_code_scanner),
              label: const Text('Start Scanning'),
              style: ElevatedButton.styleFrom(
                padding: const EdgeInsets.symmetric(vertical: 12),
              ),
            ),
          ),
        ],
      ),
    );
  }

  // HELPER METHODS

  // Color picker
  Widget _buildColorPicker(
      String label, Color color, Function(Color) onSelect) {
    return Column(
      children: [
        Text(label),
        const SizedBox(height: 4),
        InkWell(
          onTap: () {
            // In a real app, you would use a color picker
            // Here we'll just cycle through some preset colors
            final colors = [
              Colors.black,
              Colors.blue,
              Colors.red,
              Colors.green,
              Colors.purple,
              Colors.orange,
              Colors.teal,
              Colors.pink,
              Colors.white,
            ];

            int index = colors.indexOf(color);
            if (index == -1) index = 0;

            onSelect(colors[(index + 1) % colors.length]);
          },
          child: Container(
            width: 40,
            height: 40,
            decoration: BoxDecoration(
              color: color,
              border: Border.all(color: Colors.grey),
              borderRadius: BorderRadius.circular(4),
            ),
          ),
        ),
      ],
    );
  }

  Widget _buildResultRow(String label, String value) {
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 4),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Text(
            label,
            style: const TextStyle(
              fontWeight: FontWeight.bold,
              color: Colors.grey,
            ),
          ),
          const SizedBox(height: 4),
          Text(value),
        ],
      ),
    );
  }

  String _formatTime(DateTime time) {
    return '${time.year}-${time.month}-${time.day} ${time.hour}:${time.minute}:${time.second}';
  }

  // Export functions
  void _saveCurrentQR() async {
    try {
      final filePath = await QrExporter.saveToFile(
        data: _demoUrl,
        type: QrBarType.qr,
        qrStyle: _currentStyle,
        fg: _fgColor,
        bg: _bgColor,
        secondaryColor: _secondaryColor,
        tertiaryColor: _tertiaryColor,
        filename: 'qrbar_${_currentStyle.toString().split('.').last}',
      );

      _showMessage(
        filePath != null ? 'Saved to: $filePath' : 'Failed to save QR code',
        filePath == null,
      );
    } catch (e) {
      _showMessage('Error: $e', true);
    }
  }

  void _shareCurrentQR() async {
    try {
      await QrExporter.share(
        data: _demoUrl,
        type: QrBarType.qr,
        qrStyle: _currentStyle,
        fg: _fgColor,
        bg: _bgColor,
        secondaryColor: _secondaryColor,
        tertiaryColor: _tertiaryColor,
        subject: 'QR Code with ${_currentStyle.label} style',
      );
    } catch (e) {
      _showMessage('Error: $e', true);
    }
  }

  void _saveBarcode(String data, QrBarType type) async {
    try {
      final filePath = await QrExporter.saveToFile(
        data: data,
        type: type,
        filename: '${type.toString().split('.').last}_example',
      );

      _showMessage(
        filePath != null ? 'Saved to: $filePath' : 'Failed to save barcode',
        filePath == null,
      );
    } catch (e) {
      _showMessage('Error: $e', true);
    }
  }

  void _shareBarcode(String data, QrBarType type) async {
    try {
      await QrExporter.share(
        data: data,
        type: type,
        subject: '${type.label} Example',
      );
    } catch (e) {
      _showMessage('Error: $e', true);
    }
  }

  void _showMessage(String message, bool isError) {
    final scaffoldMessenger =
        ScaffoldMessenger.of(navigatorKey.currentContext!);
    scaffoldMessenger.showSnackBar(
      SnackBar(
        content: Text(message),
        backgroundColor: isError ? Colors.red : Colors.green,
      ),
    );
  }

  // Global key for showing messages
  static final navigatorKey = GlobalKey<NavigatorState>();
}