reading test receipt text detected OK

2026-08-28 19:14:38 +02:00
parent 0311b8955a
commit 2d8fc46a30
31 changed files with 356 additions and 2289 deletions
@@ -0,0 +1,192 @@
+/// Single screen: capture or pick a receipt photo, then show raw OCR text.
+library;
+
+import 'dart:io';
+
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:google_mlkit_text_recognition/google_mlkit_text_recognition.dart';
+import 'package:image_picker/image_picker.dart';
+
+import 'utils/constants.dart';
+
+class ScanScreen extends StatefulWidget {
+  const ScanScreen({super.key});
+
+  @override
+  State<ScanScreen> createState() => _ScanScreenState();
+}
+
+class _ScanScreenState extends State<ScanScreen> {
+  final ImagePicker _picker = ImagePicker();
+
+  String _extractedText = '';
+  bool _busy = false;
+  String? _error;
+
+  @override
+  void initState() {
+    super.initState();
+    _recoverLostImage();
+  }
+
+  /// Android may kill the activity while the camera app is open.
+  Future<void> _recoverLostImage() async {
+    try {
+      final response = await _picker.retrieveLostData();
+      if (!mounted || response.isEmpty) return;
+      final file = response.file;
+      if (file != null) {
+        await _runOcr(file.path);
+      }
+    } on UnimplementedError {
+      // Desktop / platforms that do not support lost-data recovery.
+    }
+  }
+
+  Future<void> _capture(ImageSource source) async {
+    final file = await _picker.pickImage(
+      source: source,
+      imageQuality: 95,
+    );
+    if (file == null || !mounted) return;
+    await _runOcr(file.path);
+  }
+
+  Future<void> _scanSampleReceipt() async {
+    try {
+      final data = await rootBundle.load(kSampleReceiptAsset);
+      final file = File(
+        '${Directory.systemTemp.path}/receipity_sample_receipt.jpeg',
+      );
+      await file.writeAsBytes(data.buffer.asUint8List(), flush: true);
+      if (!mounted) return;
+      await _runOcr(file.path);
+    } catch (_) {
+      if (!mounted) return;
+      setState(() {
+        _error = 'Could not load the sample receipt.';
+      });
+    }
+  }
+
+  Future<void> _runOcr(String imagePath) async {
+    setState(() {
+      _busy = true;
+      _error = null;
+      _extractedText = '';
+    });
+
+    final recognizer = TextRecognizer(script: TextRecognitionScript.latin);
+    try {
+      final inputImage = InputImage.fromFilePath(imagePath);
+      final recognized = await recognizer.processImage(inputImage);
+      if (!mounted) return;
+      setState(() {
+        _extractedText = recognized.text.trim();
+        if (_extractedText.isEmpty) {
+          _error = 'No text found in this image.';
+        }
+      });
+    } catch (error) {
+      if (!mounted) return;
+      setState(() {
+        _error = 'Could not read text from this image.';
+      });
+    } finally {
+      await recognizer.close();
+      if (mounted) {
+        setState(() => _busy = false);
+      }
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+
+    return Scaffold(
+      appBar: AppBar(title: const Text(kAppName)),
+      body: SafeArea(
+        child: Padding(
+          padding: const EdgeInsets.all(16),
+          child: Column(
+            crossAxisAlignment: CrossAxisAlignment.stretch,
+            children: [
+              FilledButton.icon(
+                onPressed: _busy ? null : () => _capture(ImageSource.camera),
+                icon: const Icon(Icons.photo_camera_outlined),
+                label: const Text('Take photo'),
+              ),
+              const SizedBox(height: 8),
+              OutlinedButton.icon(
+                onPressed: _busy ? null : () => _capture(ImageSource.gallery),
+                icon: const Icon(Icons.photo_library_outlined),
+                label: const Text('Pick from gallery'),
+              ),
+              const SizedBox(height: 8),
+              TextButton.icon(
+                onPressed: _busy ? null : _scanSampleReceipt,
+                icon: const Icon(Icons.receipt_long_outlined),
+                label: const Text('Use sample receipt'),
+              ),
+              if (_busy) ...[
+                const SizedBox(height: 16),
+                const LinearProgressIndicator(),
+                const SizedBox(height: 8),
+                Text(
+                  'Reading text…',
+                  style: theme.textTheme.bodyMedium,
+                ),
+              ],
+              const SizedBox(height: 16),
+              Expanded(child: _ResultPane(text: _extractedText, error: _error)),
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+}
+
+class _ResultPane extends StatelessWidget {
+  const _ResultPane({required this.text, required this.error});
+
+  final String text;
+  final String? error;
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+
+    if (error != null && text.isEmpty) {
+      return Center(
+        child: Text(
+          error!,
+          textAlign: TextAlign.center,
+          style: theme.textTheme.bodyLarge,
+        ),
+      );
+    }
+
+    if (text.isEmpty) {
+      return Center(
+        child: Text(
+          'Take a photo of a shopping receipt, or pick one from the gallery.\n\nExtracted text will show up here.',
+          textAlign: TextAlign.center,
+          style: theme.textTheme.bodyLarge,
+        ),
+      );
+    }
+
+    return SingleChildScrollView(
+      child: SelectableText(
+        text,
+        style: theme.textTheme.bodyLarge?.copyWith(
+          color: theme.colorScheme.onSurface,
+          height: 1.4,
+        ),
+      ),
+    );
+  }
+}