Getting basic functionalities over from the OCR app like the camera.

Changes to be committed:
    modified:   lib/main.dart
    new file:   lib/result_screen.dart
    modified:   pubspec.lock
    modified:   pubspec.yaml
    modified:   test/widget_test.dart

2 files changed, 232 insertions, 71 deletions

diff --git a/lib/main.dart b/lib/main.dart
index d7cd012..30c90ef 100644
--- a/lib/main.dart
+++ b/lib/main.dart
@@ -1,107 +1,249 @@
 import 'package:camera/camera.dart';
 import 'package:permission_handler/permission_handler.dart';
+import 'package:google_mlkit_text_recognition/google_mlkit_text_recognition.dart';
+import 'package:google_mlkit_object_detection/google_mlkit_object_detection.dart';
 import 'package:flutter_tflite/flutter_tflite.dart';
 import 'package:flutter_tts/flutter_tts.dart';
+import 'package:yolo/result_screen.dart';
 
 import 'package:flutter/material.dart';
 import 'dart:io';
 
 void main() {
-  runApp(const MyApp());
+  runApp(const App());
 }
 
-class MyApp extends StatelessWidget {
-  const MyApp({super.key});
+class App extends StatelessWidget {
+  const App({super.key});
 
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
-      title: 'Flutter Demo',
+      title: 'MegaView',
       theme: ThemeData(
         colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurpleAccent),
         useMaterial3: true,
       ),
       debugShowCheckedModeBanner: false,
-      home: const MyHomePage(title: 'Flutter Demo Home Page'),
+      home: const MainScreen(),
     );
   }
 }
 
-class MyHomePage extends StatefulWidget {
-  const MyHomePage({super.key, required this.title});
-
-  final String title;
+class MainScreen extends StatefulWidget {
+  const MainScreen({super.key});
 
   @override
-  State<MyHomePage> createState() => _MyHomePageState();
+  State<MainScreen> createState() => _MainScreenState();
 }
 
-class _MyHomePageState extends State<MyHomePage> {
-  int _counter = 0;
-
-  void _incrementCounter() {
-    setState(() {
-      // This call to setState tells the Flutter framework that something has
-      // changed in this State, which causes it to rerun the build method below
-      // so that the display can reflect the updated values. If we changed
-      // _counter without calling setState(), then the build method would not be
-      // called again, and so nothing would appear to happen.
-      _counter++;
-    });
+class _MainScreenState extends State<MainScreen> with WidgetsBindingObserver {
+  bool _isPermissionGranted = false;
+
+  late final Future<void> _future;
+  CameraController? _cameraController;
+
+  final textRecognizer = TextRecognizer();
+
+  FlutterTts flutterTts = FlutterTts(); // TTS
+
+  @override
+  void initState() {
+    super.initState();
+    initTTS(); // TTS
+
+    WidgetsBinding.instance.addObserver(this);
+
+    _future = _requestCameraPermission();
+  }
+
+  Future<void> initTTS() async { // TTS
+    await flutterTts.setLanguage("en-US"); // Set the language you want
+    await flutterTts.setSpeechRate(0.5); // Adjust speech rate (1.0 is normal but too fast for my liking)
+    await flutterTts.setVolume(1.0); // Adjust volume (0.0 to 1.0)
+    await flutterTts.setPitch(1.0); // Adjust pitch (1.0 is normal)
+
+    // You can set other configurations as well
+
+    // Check if TTS is available
+    // bool isAvailable = await flutterTts.isLanguageAvailable("en-US");
+    // print("TTS is available: $isAvailable");
+  }
+
+  Future<void> speak(String text) async {
+    await flutterTts.speak(text); // TTS
+  }
+
+  @override
+  void dispose() {
+    WidgetsBinding.instance.removeObserver(this);
+    _stopCamera();
+    textRecognizer.close();
+    flutterTts.stop(); // TTS Stop
+    super.dispose();
+  }
+
+  @override
+  void didChangeAppLifecycleState(AppLifecycleState state) {
+    if (_cameraController == null || !_cameraController!.value.isInitialized) {
+      return;
+    }
+
+    if (state == AppLifecycleState.inactive) {
+      _stopCamera();
+    } else if (state == AppLifecycleState.resumed &&
+        _cameraController != null &&
+        _cameraController!.value.isInitialized) {
+      _startCamera();
+    }
   }
 
   @override
   Widget build(BuildContext context) {
-    // This method is rerun every time setState is called, for instance as done
-    // by the _incrementCounter method above.
-    //
-    // The Flutter framework has been optimized to make rerunning build methods
-    // fast, so that you can just rebuild anything that needs updating rather
-    // than having to individually change instances of widgets.
-    return Scaffold(
-      appBar: AppBar(
-        // TRY THIS: Try changing the color here to a specific color (to
-        // Colors.amber, perhaps?) and trigger a hot reload to see the AppBar
-        // change color while the other colors stay the same.
-        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
-        // Here we take the value from the MyHomePage object that was created by
-        // the App.build method, and use it to set our appbar title.
-        title: Text(widget.title),
-      ),
-      body: Center(
-        // Center is a layout widget. It takes a single child and positions it
-        // in the middle of the parent.
-        child: Column(
-          // Column is also a layout widget. It takes a list of children and
-          // arranges them vertically. By default, it sizes itself to fit its
-          // children horizontally, and tries to be as tall as its parent.
-          //
-          // Column has various properties to control how it sizes itself and
-          // how it positions its children. Here we use mainAxisAlignment to
-          // center the children vertically; the main axis here is the vertical
-          // axis because Columns are vertical (the cross axis would be
-          // horizontal).
-          //
-          // TRY THIS: Invoke "debug painting" (choose the "Toggle Debug Paint"
-          // action in the IDE, or press "p" in the console), to see the
-          // wireframe for each widget.
-          mainAxisAlignment: MainAxisAlignment.center,
-          children: <Widget>[
-            const Text(
-              'You have pushed the button this many times:',
-            ),
-            Text(
-              '$_counter',
-              style: Theme.of(context).textTheme.headlineMedium,
+    return FutureBuilder(
+      future: _future,
+      builder: (context, snapshot) {
+        return Stack(
+          children: [
+            if (_isPermissionGranted)
+              FutureBuilder<List<CameraDescription>>(
+                future: availableCameras(),
+                builder: (context, snapshot) {
+                  if (snapshot.hasData) {
+                    _initCameraController(snapshot.data!);
+
+                    return Center(child: CameraPreview(_cameraController!));
+                  } else {
+                    return const LinearProgressIndicator();
+                  }
+                },
+              ),
+            Scaffold(
+              appBar: AppBar(
+                backgroundColor: Theme.of(context).colorScheme.inversePrimary,
+                title: const Text('MegaView Text Recognition'),
+              ),
+              backgroundColor: _isPermissionGranted ? Colors.transparent : null,
+              body: _isPermissionGranted
+                  ? Column(
+                mainAxisAlignment: MainAxisAlignment.end,
+                children: [
+                  Container(),
+                  Container(
+                    color: Theme.of(context).colorScheme.inversePrimary,
+                    alignment: Alignment.center,
+                    child: Padding(
+                      padding: const EdgeInsets.symmetric(vertical: 8.0),
+                      child: ElevatedButton(
+                        onPressed: _scanImage,
+                        style: ButtonStyle(
+                          minimumSize: MaterialStateProperty.all<Size>(
+                            const Size(256, 64), // Set the desired width and height
+                          ),
+                        ),
+                        child: const Text('Scan text'),
+                      ),
+                    ),
+                  ),
+                ],
+              )
+                  : Center(
+                child: Container(
+                  padding: const EdgeInsets.only(left: 24.0, right: 24.0),
+                  child: const Text(
+                    'Camera permission denied',
+                    textAlign: TextAlign.center,
+                  ),
+                ),
+              ),
             ),
           ],
-        ),
-      ),
-      floatingActionButton: FloatingActionButton(
-        onPressed: _incrementCounter,
-        tooltip: 'Increment',
-        child: const Icon(Icons.add),
-      ), // This trailing comma makes auto-formatting nicer for build methods.
+        );
+      },
     );
   }
-}
+
+  Future<void> _requestCameraPermission() async {
+    final status = await Permission.camera.request();
+    _isPermissionGranted = status == PermissionStatus.granted;
+  }
+
+  void _startCamera() {
+    if (_cameraController != null) {
+      _cameraSelected(_cameraController!.description);
+    }
+  }
+
+  void _stopCamera() {
+    if (_cameraController != null) {
+      _cameraController?.dispose();
+    }
+  }
+
+  void _initCameraController(List<CameraDescription> cameras) {
+    if (_cameraController != null) {
+      return;
+    }
+
+    // Select the first rear camera.
+    CameraDescription? camera;
+    for (var i = 0; i < cameras.length; i++) {
+      final CameraDescription current = cameras[i];
+      if (current.lensDirection == CameraLensDirection.back) {
+        camera = current;
+        break;
+      }
+    }
+
+    if (camera != null) {
+      _cameraSelected(camera);
+    }
+  }
+
+  Future<void> _cameraSelected(CameraDescription camera) async {
+    _cameraController = CameraController(
+      camera,
+      ResolutionPreset.high,
+      enableAudio: false,
+    );
+
+    await _cameraController!.initialize();
+    await _cameraController!.setFlashMode(FlashMode.off);
+
+    if (!mounted) {
+      return;
+    }
+    setState(() {});
+  }
+
+  Future<void> _scanImage() async {
+    if (_cameraController == null) return;
+
+    final navigator = Navigator.of(context);
+
+    try {
+      final pictureFile = await _cameraController!.takePicture();
+
+      final file = File(pictureFile.path);
+
+      final inputImage = InputImage.fromFile(file);
+      final recognizedText = await textRecognizer.processImage(inputImage);
+
+      speak(recognizedText.text);
+
+      await navigator.push(
+        MaterialPageRoute(
+            builder: (BuildContext context) =>
+                ResultScreen(text: recognizedText.text)
+        ),
+      );
+    } catch (e) {
+      // ignore: use_build_context_synchronously
+      ScaffoldMessenger.of(context).showSnackBar(
+        const SnackBar(
+          content: Text('An error occurred when scanning text'),
+        ),
+      );
+    }
+  }
+}
\ No newline at end of file
diff --git a/lib/result_screen.dart b/lib/result_screen.dart
new file mode 100644
index 0000000..d5a64ea
--- /dev/null
+++ b/lib/result_screen.dart
@@ -0,0 +1,19 @@
+import 'package:flutter/material.dart';
+
+class ResultScreen extends StatelessWidget {
+  final String text;
+
+  const ResultScreen({super.key, required this.text});
+
+  @override
+  Widget build(BuildContext context) => Scaffold(
+    appBar: AppBar(
+      //backgroundColor: Theme.of(context).colorScheme.inversePrimary,
+      title: const Text('Result'),
+    ),
+    body: Container(
+      padding: const EdgeInsets.all(30.0),
+      child: Text(text),
+    ),
+  );
+}
\ No newline at end of file