use the scanner example from CamerAwesome for starting point

mobile/android/app/build.gradle

@@ -47,7 +47,7 @@ android {
         applicationId "com.nebcorp_hias.cuttle"
         // You can update the following values to match your application needs.
         // For more information, see: https://docs.flutter.dev/deployment/android#reviewing-the-gradle-build-configuration.
-        minSdkVersion flutter.minSdkVersion
+        minSdkVersion 32
         targetSdkVersion flutter.targetSdkVersion
         versionCode flutterVersionCode.toInteger()
         versionName flutterVersionName

mobile/android/build.gradle

@@ -1,5 +1,5 @@
 buildscript {
-    ext.kotlin_version = '1.7.10'
+    ext.kotlin_version = '1.8.22'
     repositories {
         google()
         mavenCentral()

mobile/lib/main.dart

@@ -1,147 +1,173 @@
+import 'dart:async';
+
+import 'package:cuttle/utils/mlkit_utils.dart';
+import 'package:camerawesome/camerawesome_plugin.dart';
 import 'package:flutter/material.dart';
 import 'ffi.dart' if (dart.library.html) 'ffi_web.dart';
+import 'package:google_mlkit_barcode_scanning/google_mlkit_barcode_scanning.dart';
+import 'package:rxdart/rxdart.dart';
 
 void main() {
   runApp(const MyApp());
 }
 
 class MyApp extends StatelessWidget {
-  const MyApp({Key? key}) : super(key: key);
+  const MyApp({super.key});
 
-  // This widget is the root of your application.
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
-      title: 'Flutter Demo',
+      title: 'camerAwesome App',
       theme: ThemeData(
-        // This is the theme of your application.
-        //
-        // Try running your application with "flutter run". You'll see the
-        // application has a blue toolbar. Then, without quitting the app, try
-        // changing the primarySwatch below to Colors.green and then invoke
-        // "hot reload" (press "r" in the console where you ran "flutter run",
-        // or simply save your changes to "hot reload" in a Flutter IDE).
-        // Notice that the counter didn't reset back to zero; the application
-        // is not restarted.
         primarySwatch: Colors.blue,
       ),
-      home: const MyHomePage(title: 'Flutter Demo Home Page'),
+      home: const MyHomePage(),
     );
   }
 }
 
 class MyHomePage extends StatefulWidget {
-  const MyHomePage({Key? key, required this.title}) : super(key: key);
+  const MyHomePage({super.key});
-
-  // This widget is the home page of your application. It is stateful, meaning
-  // that it has a State object (defined below) that contains fields that affect
-  // how it looks.
-
-  // This class is the configuration for the state. It holds the values (in this
-  // case the title) provided by the parent (in this case the App widget) and
-  // used by the build method of the State. Fields in a Widget subclass are
-  // always marked "final".
-
-  final String title;
 
   @override
   State<MyHomePage> createState() => _MyHomePageState();
 }
 
 class _MyHomePageState extends State<MyHomePage> {
-  // These futures belong to the state and are only initialized once,
+  final _barcodeScanner = BarcodeScanner(formats: [BarcodeFormat.qrCode]);
-  // in the initState method.
+
-  late Future<Platform> platform;
+  final _buffer = <String>[];
-  late Future<bool> isRelease;
+  final _barcodesController = BehaviorSubject<List<String>>();
+  late final Stream<List<String>> _barcodesStream = _barcodesController.stream;
+  final _scrollController = ScrollController();
 
   @override
-  void initState() {
+  void dispose() {
-    super.initState();
+    _barcodesController.close();
-    platform = api.platform();
+    super.dispose();
-    isRelease = api.rustReleaseMode();
   }
 
   @override
   Widget build(BuildContext context) {
-    // This method is rerun every time setState is called.
-    //
-    // 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(
+      body: CameraAwesomeBuilder.previewOnly(
-        // Here we take the value from the MyHomePage object that was created by
+        onImageForAnalysis: (img) => _processImageBarcode(img),
-        // the App.build method, and use it to set our appbar title.
+        imageAnalysisConfig: AnalysisConfig(
-        title: Text(widget.title),
+          androidOptions: const AndroidAnalysisOptions.nv21(
-      ),
+            width: 1024,
-      body: Center(
+          ),
-        // Center is a layout widget. It takes a single child and positions it
+          maxFramesPerSecond: 5,
-        // in the middle of the parent.
+          autoStart: false,
-        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.
-          //
-          // Invoke "debug painting" (press "p" in the console, choose the
-          // "Toggle Debug Paint" action from the Flutter Inspector in Android
-          // Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
-          // to see the wireframe for each widget.
-          //
-          // 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).
-          mainAxisAlignment: MainAxisAlignment.center,
-          children: <Widget>[
-            const Text("You're running on"),
-            // To render the results of a Future, a FutureBuilder is used which
-            // turns a Future into an AsyncSnapshot, which can be used to
-            // extract the error state, the loading state and the data if
-            // available.
-            //
-            // Here, the generic type that the FutureBuilder manages is
-            // explicitly named, because if omitted the snapshot will have the
-            // type of AsyncSnapshot<Object?>.
-            FutureBuilder<List<dynamic>>(
-              // We await two unrelated futures here, so the type has to be
-              // List<dynamic>.
-              future: Future.wait([platform, isRelease]),
-              builder: (context, snap) {
-                final style = Theme.of(context).textTheme.headlineMedium;
-                if (snap.error != null) {
-                  // An error has been encountered, so give an appropriate response and
-                  // pass the error details to an unobstructive tooltip.
-                  debugPrint(snap.error.toString());
-                  return Tooltip(
-                    message: snap.error.toString(),
-                    child: Text('Unknown OS', style: style),
-                  );
-                }
-
-                // Guard return here, the data is not ready yet.
-                final data = snap.data;
-                if (data == null) return const CircularProgressIndicator();
-
-                // Finally, retrieve the data expected in the same order provided
-                // to the FutureBuilder.future.
-                final Platform platform = data[0];
-                final release = data[1] ? 'Release' : 'Debug';
-                final text = const {
-                      Platform.AndroidBish: 'Android, bish',
-                      Platform.Ios: 'iOS',
-                      Platform.MacApple: 'MacOS with Apple Silicon',
-                      Platform.MacIntel: 'MacOS',
-                      Platform.Windows: 'Windows',
-                      Platform.Unix: 'Unix',
-                      Platform.Wasm: 'the Web',
-                    }[platform] ??
-                    'Unknown OS';
-                return Text('$text ($release)', style: style);
-              },
-            )
-          ],
         ),
+        builder: (cameraModeState, previewSize, previewRect) {
+          return _BarcodeDisplayWidget(
+            barcodesStream: _barcodesStream,
+            scrollController: _scrollController,
+            analysisController: cameraModeState.analysisController!,
+          );
+        },
+      ),
+    );
+  }
+
+  Future _processImageBarcode(AnalysisImage img) async {
+    final inputImage = toInputImage(img as Nv21Image);
+
+    try {
+      var recognizedBarCodes = await _barcodeScanner.processImage(inputImage);
+      for (Barcode barcode in recognizedBarCodes) {
+        debugPrint("Barcode: [${barcode.format}]: ${barcode.rawBytes}");
+        _addBarcode("[${barcode.format.name}]: ${barcode.rawValue}");
+      }
+    } catch (error) {
+      debugPrint("...sending image resulted error $error");
+    }
+  }
+
+  void _addBarcode(String value) {
+    try {
+      if (_buffer.length > 300) {
+        _buffer.removeRange(_buffer.length - 300, _buffer.length);
+      }
+      if (_buffer.isEmpty || value != _buffer[0]) {
+        _buffer.insert(0, value);
+        _barcodesController.add(_buffer);
+        _scrollController.animateTo(
+          0,
+          duration: const Duration(milliseconds: 400),
+          curve: Curves.fastLinearToSlowEaseIn,
+        );
+      }
+    } catch (err) {
+      debugPrint("...logging error $err");
+    }
+  }
+}
+
+class _BarcodeDisplayWidget extends StatefulWidget {
+  final Stream<List<String>> barcodesStream;
+  final ScrollController scrollController;
+
+  final AnalysisController analysisController;
+
+  const _BarcodeDisplayWidget({
+    // ignore: unused_element
+    super.key,
+    required this.barcodesStream,
+    required this.scrollController,
+    required this.analysisController,
+  });
+
+  @override
+  State<_BarcodeDisplayWidget> createState() => _BarcodeDisplayWidgetState();
+}
+
+class _BarcodeDisplayWidgetState extends State<_BarcodeDisplayWidget> {
+  @override
+  Widget build(BuildContext context) {
+    return Align(
+      alignment: Alignment.bottomCenter,
+      child: Container(
+        decoration: BoxDecoration(
+          color: Colors.tealAccent.withOpacity(0.7),
+        ),
+        child: Column(mainAxisSize: MainAxisSize.min, children: [
+          Material(
+            color: Colors.transparent,
+            child: CheckboxListTile(
+              value: widget.analysisController.enabled,
+              onChanged: (newValue) async {
+                if (widget.analysisController.enabled == true) {
+                  await widget.analysisController.stop();
+                } else {
+                  await widget.analysisController.start();
+                }
+                setState(() {});
+              },
+              title: const Text(
+                "Enable barcode scan",
+                style: TextStyle(fontWeight: FontWeight.bold),
+              ),
+            ),
+          ),
+          Container(
+            height: 120,
+            padding: const EdgeInsets.symmetric(horizontal: 16),
+            child: StreamBuilder<List<String>>(
+              stream: widget.barcodesStream,
+              builder: (context, value) => !value.hasData
+                  ? const SizedBox.expand()
+                  : ListView.separated(
+                      padding: const EdgeInsets.only(top: 8),
+                      controller: widget.scrollController,
+                      itemCount: value.data!.length,
+                      separatorBuilder: (context, index) =>
+                          const SizedBox(height: 4),
+                      itemBuilder: (context, index) => Text(value.data![index]),
+                    ),
+            ),
+          ),
+        ]),
       ),
     );
   }

mobile/lib/utils/file_utils.dart

@@ -0,0 +1,14 @@
+import 'dart:io';
+
+import 'package:camerawesome/camerawesome_plugin.dart';
+import 'package:path_provider/path_provider.dart';
+
+Future<String> path(CaptureMode captureMode) async {
+  final Directory extDir = await getTemporaryDirectory();
+  final testDir =
+      await Directory('${extDir.path}/test').create(recursive: true);
+  final String fileExtension = captureMode == CaptureMode.photo ? 'jpg' : 'mp4';
+  final String filePath =
+      '${testDir.path}/${DateTime.now().millisecondsSinceEpoch}.$fileExtension';
+  return filePath;
+}

mobile/lib/utils/mlkit_utils.dart

@@ -0,0 +1,23 @@
+import 'package:camerawesome/camerawesome_plugin.dart';
+import 'package:google_mlkit_commons/google_mlkit_commons.dart';
+
+InputImage toInputImage(Nv21Image aimg) {
+  final planeData = aimg.planes
+      .map((e) => InputImagePlaneMetadata(
+          bytesPerRow: e.bytesPerRow, height: aimg.height, width: aimg.width))
+      .toList();
+
+  return InputImage.fromBytes(
+    bytes: aimg.bytes,
+    inputImageData: InputImageData(
+      imageRotation: getRotation(aimg),
+      inputImageFormat: InputImageFormat.nv21,
+      planeData: planeData,
+      size: aimg.size,
+    ),
+  );
+}
+
+InputImageRotation getRotation(AnalysisImage img) {
+  return InputImageRotation.values.byName(img.rotation.name);
+}

mobile/pubspec.yaml

@@ -38,6 +38,14 @@ dependencies:
   flutter_rust_bridge: ^1.45.0
   meta: ^1.8.0
   uuid: ^3.0.7
+  path_provider: ^2.1.0
+  path: ^1.8.3
+  mobile_scanner: ^3.4.1
+  camerawesome: ^1.4.0
+  google_mlkit_barcode_scanning: ^0.5.0
+  rxdart: ^0.27.7
+  image: ^4.0.17
+  google_mlkit_commons: ^0.2.0
 
 dev_dependencies:
   flutter_test: