name: flutter_ocr_app description: "A Flutter application for performing OCR on PDF files using a backend API." publish_to: 'none' # Remove this line if you wish to publish to pub.dev version: 1.0.0+1 environment: sdk: '>=3.0.0 <4.0.0' dependencies: flutter: sdk: flutter cupertino_icons: ^1.0.6 file_picker: ^6.1.1 # For picking files http: ^1.1.0 # For making HTTP requests pdfx: ^2.5.0 # For handling PDF files and rendering pages to images path_provider: ^2.1.1 # To get temporary directory for image storage permission_handler: ^11.1.0 # To handle storage permissions (especially on Android >= 10) dev_dependencies: flutter_test: sdk: flutter flutter_lints: ^3.0.1 flutter: uses-material-design: true import 'package:flutter/material.dart'; import 'package:flutter_ocr_app/screens/ocr_screen.dart'; void main() { runApp(const MyApp()); } class MyApp extends StatelessWidget { const MyApp({super.key}); @override Widget build(BuildContext context) { return MaterialApp( title: 'Flutter PDF OCR', theme: ThemeData( colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple), useMaterial3: true, scaffoldBackgroundColor: Colors.grey[100], appBarTheme: AppBarTheme( backgroundColor: Colors.deepPurple[400], foregroundColor: Colors.white, elevation: 4, ), elevatedButtonTheme: ElevatedButtonThemeData( style: ElevatedButton.styleFrom( backgroundColor: Colors.deepPurple[400], foregroundColor: Colors.white, padding: const EdgeInsets.symmetric(horizontal: 20, vertical: 12), textStyle: const TextStyle(fontSize: 16), shape: RoundedRectangleBorder( borderRadius: BorderRadius.circular(8), ), ), ), cardTheme: CardTheme( elevation: 2, shape: RoundedRectangleBorder( borderRadius: BorderRadius.circular(12), ), margin: const EdgeInsets.symmetric(vertical: 8, horizontal: 0), ), ), home: const OcrScreen(), debugShowCheckedModeBanner: false, ); } } import 'dart:convert'; import 'dart:io'; import 'dart:typed_data'; import 'package:flutter/material.dart'; import 'package:file_picker/file_picker.dart'; import 'package:http/http.dart' as http; import 'package:pdfx/pdfx.dart'; import 'package:path_provider/path_provider.dart'; import 'package:permission_handler/permission_handler.dart'; // Import permission_handler class OcrScreen extends StatefulWidget { const OcrScreen({super.key}); @override State createState() => _OcrScreenState(); } class _OcrScreenState extends State { // --- State Variables --- File? _selectedPdfFile; String _ocrResult = ''; bool _isLoading = false; String? _errorMessage; String _loadingMessage = ''; int _totalPages = 0; int _processedPages = 0; // --- Configuration --- // IMPORTANT: Replace with your actual backend API URL final String _apiUrl = 'http://10.0.2.2:5000/ocr'; // Use 10.0.2.2 for Android emulator accessing localhost // --- Methods --- Future _requestPermissions() async { // Request storage permission var status = await Permission.storage.status; if (!status.isGranted) { status = await Permission.storage.request(); if (!status.isGranted) { setState(() { _errorMessage = 'Storage permission is required to pick files.'; }); // Optionally, show a dialog explaining why permission is needed // and guide the user to settings using openAppSettings() } } } Future _pickPdf() async { await _requestPermissions(); // Request permission before picking setState(() { _errorMessage = null; // Clear previous errors _ocrResult = ''; // Clear previous results _selectedPdfFile = null; // Clear previous selection _totalPages = 0; _processedPages = 0; }); try { FilePickerResult? result = await FilePicker.platform.pickFiles( type: FileType.custom, allowedExtensions: ['pdf'], ); if (result != null && result.files.single.path != null) { setState(() { _selectedPdfFile = File(result.files.single.path!); }); } else { // User canceled the picker if (mounted) { ScaffoldMessenger.of(context).showSnackBar( const SnackBar(content: Text('No PDF file selected.')), ); } } } catch (e) { print('Error picking PDF: $e'); setState(() { _errorMessage = 'Error picking PDF: $e'; }); } } Future _performOcr() async { if (_selectedPdfFile == null) { setState(() { _errorMessage = 'Please select a PDF file first.'; }); return; } setState(() { _isLoading = true; _errorMessage = null; _ocrResult = ''; _loadingMessage = 'Initializing OCR...'; _totalPages = 0; _processedPages = 0; }); PdfController? pdfController; Directory? tempDir; List pageTexts = []; try { // Get temporary directory tempDir = await getTemporaryDirectory(); // Load PDF document setState(() { _loadingMessage = 'Loading PDF...'; }); pdfController = PdfController( document: PdfDocument.openFile(_selectedPdfFile!.path), ); // Wait for the controller to be ready (important!) await pdfController.loadDocument(PdfDocument.openFile(_selectedPdfFile!.path)); _totalPages = pdfController.pagesCount ?? 0; if (_totalPages == 0) { throw Exception("Could not read pages from PDF."); } setState(() { _loadingMessage = 'Processing $_totalPages pages...'; }); // Process each page for (int i = 1; i <= _totalPages; i++) { setState(() { _processedPages = i; _loadingMessage = 'Processing page $i of $_totalPages...'; }); final page = await pdfController.getPage(i); if (page == null) { print('Warning: Could not get page $i'); continue; // Skip if page data is null } // Render page to image (adjust quality/format as needed) final pageImage = await page.render( width: page.width * 2, // Increase resolution for better OCR height: page.height * 2, format: PdfPageImageFormat.jpeg, quality: 90, // Adjust quality vs size ); await page.close(); // Close page after rendering if (pageImage == null) { print('Warning: Could not render page $i to image'); continue; // Skip if rendering failed } // --- Send image to backend API --- setState(() { _loadingMessage = 'Sending page $i for OCR...'; }); final String pageOcrText = await _uploadImageAndGetOcr(pageImage.bytes, 'page_$i.jpg'); pageTexts.add(pageOcrText); // --- End Send --- // Optional: Clean up temporary image file if saved (not needed here as we use bytes) } setState(() { _ocrResult = pageTexts.join('\n\n---\n\n'); // Join page results _loadingMessage = 'OCR Complete!'; }); } catch (e) { print('OCR Error: $e'); setState(() { _errorMessage = 'An error occurred during OCR: $e'; }); } finally { // Ensure PDF controller is disposed pdfController?.dispose(); // Optional: Clean up temporary directory if needed, though OS usually handles it. // if (tempDir != null && await tempDir.exists()) { // // await tempDir.delete(recursive: true); // Be careful with this // } setState(() { _isLoading = false; _loadingMessage = ''; // Clear loading message }); } } Future _uploadImageAndGetOcr(Uint8List imageData, String filename) async { try { var request = http.MultipartRequest('POST', Uri.parse(_apiUrl)); // Add image file to the request request.files.add(http.MultipartFile.fromBytes( 'image', // Must match the key expected by the backend ("image") imageData, filename: filename, // Provide a filename )); // Send request var streamedResponse = await request.send().timeout(const Duration(seconds: 90)); // Add timeout // Get response var response = await http.Response.fromStream(streamedResponse); if (response.statusCode == 200) { var jsonResponse = jsonDecode(response.body); if (jsonResponse.containsKey('text')) { return jsonResponse['text']; } else if (jsonResponse.containsKey('error')) { throw Exception('API Error: ${jsonResponse['error']}'); } else { throw Exception('Invalid API response format.'); } } else { print('API Error Status Code: ${response.statusCode}'); print('API Error Body: ${response.body}'); throw Exception('API request failed with status: ${response.statusCode}. Body: ${response.body}'); } } on SocketException catch (e) { print('Network Error: $e'); throw Exception('Network error: Could not connect to the server. Please check your connection and the API URL.'); } on http.ClientException catch (e) { print('HTTP Client Error: $e'); throw Exception('Network error: ${e.message}'); } catch (e) { print('Error uploading/processing image: $e'); rethrow; // Rethrow other exceptions } } // --- Build Method --- @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar( title: const Text('PDF OCR Processor'), ), body: SingleChildScrollView( padding: const EdgeInsets.all(16.0), child: Column( crossAxisAlignment: CrossAxisAlignment.stretch, children: [ // --- File Selection Card --- Card( child: Padding( padding: const EdgeInsets.all(16.0), child: Column( children: [ Icon( Icons.picture_as_pdf, size: 50, color: Colors.red[700], ), const SizedBox(height: 10), Text( _selectedPdfFile == null ? 'No PDF Selected' : 'Selected: ${_selectedPdfFile!.path.split('/').last}', // Show only filename style: Theme.of(context).textTheme.titleMedium, textAlign: TextAlign.center, ), const SizedBox(height: 15), ElevatedButton.icon( icon: const Icon(Icons.file_upload), label: const Text('Pick PDF File'), onPressed: _isLoading ? null : _pickPdf, ), ], ), ), ), const SizedBox(height: 20), // --- OCR Action Button --- ElevatedButton.icon( icon: const Icon(Icons.document_scanner_outlined), label: const Text('Start OCR Process'), onPressed: (_selectedPdfFile == null || _isLoading) ? null : _performOcr, style: ElevatedButton.styleFrom( padding: const EdgeInsets.symmetric(vertical: 15), ), ), const SizedBox(height: 20), // --- Loading Indicator / Progress --- if (_isLoading) Padding( padding: const EdgeInsets.symmetric(vertical: 20.0), child: Column( children: [ const CircularProgressIndicator(), const SizedBox(height: 15), Text( _loadingMessage, style: TextStyle(color: Colors.deepPurple[700], fontWeight: FontWeight.w500), textAlign: TextAlign.center, ), if (_totalPages > 0) Padding( padding: const EdgeInsets.only(top: 8.0), child: LinearProgressIndicator( value: _processedPages / _totalPages, minHeight: 6, borderRadius: BorderRadius.circular(3), ), ), ], ), ), // --- Error Message Display --- if (_errorMessage != null) Padding( padding: const EdgeInsets.symmetric(vertical: 15.0), child: Card( color: Colors.red[100], child: Padding( padding: const EdgeInsets.all(12.0), child: Text( 'Error: $_errorMessage', style: TextStyle(color: Colors.red[900], fontWeight: FontWeight.bold), textAlign: TextAlign.center, ), ), ), ), // --- OCR Result Display --- if (_ocrResult.isNotEmpty) Card( elevation: 1, child: Padding( padding: const EdgeInsets.all(16.0), child: Column( crossAxisAlignment: CrossAxisAlignment.start, children: [ Text( 'OCR Result:', style: Theme.of(context).textTheme.titleLarge?.copyWith( color: Colors.deepPurple[800], ), ), const Divider(height: 20, thickness: 1), SelectableText( _ocrResult, style: Theme.of(context).textTheme.bodyMedium?.copyWith(height: 1.5), ), ], ), ), ), ], ), ), ); } }