updates

Author: rishabnayak

example/ios/Runner.xcworkspace/xcshareddata/WorkspaceSettings.xcsettings

@@ -4,5 +4,7 @@
 <dict>
 	<key>BuildSystemType</key>
 	<string>Original</string>
+	<key>PreviewsEnabled</key>
+	<false/>
 </dict>
 </plist>

example/lib/main.dart

@@ -28,6 +28,7 @@ class _MyHomePageState extends State<_MyHomePage> {
       if (!mounted) {
         return;
       }
+      _vision.addBarcodeDetector().forEach((action) => print(action)); 
       setState(() {});
     });
   }

ios/Classes/FirebaseMlVisionPlugin.h

@@ -2,7 +2,7 @@
 
 #import "Firebase/Firebase.h"
 
-@interface FLTFirebaseMlVisionPlugin : NSObject <FlutterPlugin>
+@interface FLTFirebaseMlVisionPlugin : NSObject <FlutterPlugin, FlutterStreamHandler>
 + (void)handleError:(NSError *)error result:(FlutterResult)result;
 @end
 

ios/Classes/FirebaseMlVisionPlugin.m

@@ -139,6 +139,7 @@ - (void)setCaptureSessionPreset:(NSString *)resolutionPreset {
 - (void)captureOutput:(AVCaptureOutput *)output
 didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
        fromConnection:(AVCaptureConnection *)connection {
+    CVImageBufferRef newBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
     if (output == _captureVideoOutput) {
         CVPixelBufferRef newBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
         CFRetain(newBuffer);
@@ -210,19 +211,22 @@ @implementation FLTFirebaseMlVisionPlugin {
 }
 
 static NSMutableDictionary<NSNumber *, id<Detector>> *detectors;
+FlutterEventSink resultSink;
 
 + (void)handleError:(NSError *)error result:(FlutterResult)result {
     result(getFlutterError(error));
 }
 
 + (void)registerWithRegistrar:(NSObject<FlutterPluginRegistrar> *)registrar {
     detectors = [NSMutableDictionary new];
+    FlutterEventChannel *results = [FlutterEventChannel eventChannelWithName:@"plugins.flutter.io/firebase_mlvision_results" binaryMessenger:[registrar messenger]];
     FlutterMethodChannel *channel =
     [FlutterMethodChannel methodChannelWithName:@"plugins.flutter.io/firebase_mlvision"
                                 binaryMessenger:[registrar messenger]];
     FLTFirebaseMlVisionPlugin *instance = [[FLTFirebaseMlVisionPlugin alloc] initWithRegistry:[registrar textures]
                                                                                     messenger:[registrar messenger]];
     [registrar addMethodCallDelegate:instance channel:channel];
+    [results setStreamHandler:instance];
 
     SEL sel = NSSelectorFromString(@"registerLibrary:withVersion:");
     if ([FIRApp respondsToSelector:sel]) {
@@ -258,6 +262,8 @@ - (void)handleMethodCall:(FlutterMethodCall *)call result:(FlutterResult)result
 
 - (void)handleMethodCallAsync:(FlutterMethodCall *)call result:(FlutterResult)result {
     NSString *modelName = call.arguments[@"model"];
+    NSDictionary *options = call.arguments[@"options"];
+    NSNumber *handle = call.arguments[@"handle"];
   if ([@"ModelManager#setupLocalModel" isEqualToString:call.method]) {
     [SetupLocalModel modelName:modelName result:result];
   } else if ([@"ModelManager#setupRemoteModel" isEqualToString:call.method]) {
@@ -307,7 +313,7 @@ - (void)handleMethodCallAsync:(FlutterMethodCall *)call result:(FlutterResult)re
             int64_t textureId = [_registry registerTexture:cam];
             _camera = cam;
             cam.onFrameAvailable = ^{
-                [_registry textureFrameAvailable:textureId];
+                [self->_registry textureFrameAvailable:textureId];
             };
             FlutterEventChannel *eventChannel = [FlutterEventChannel
                                                  eventChannelWithName:[NSString
@@ -323,6 +329,12 @@ - (void)handleMethodCallAsync:(FlutterMethodCall *)call result:(FlutterResult)re
                      });
             [cam start];
         }
+    } else if ([@"BarcodeDetector#startDetection" isEqualToString:call.method]){
+        id<Detector> detector = detectors[handle];
+        if (!detector) {
+            detector = [[BarcodeDetector alloc] initWithVision:[FIRVision vision] options:options];
+            [FLTFirebaseMlVisionPlugin addDetector:handle detector:detector];
+        }
     } else if ([@"BarcodeDetector#detectInImage" isEqualToString:call.method] ||
              [@"FaceDetector#processImage" isEqualToString:call.method] ||
              [@"ImageLabeler#processImage" isEqualToString:call.method] ||
@@ -521,4 +533,14 @@ + (void)addDetector:(NSNumber *)handle detector:(id<Detector>)detector {
   detectors[handle] = detector;
 }
 
+- (FlutterError * _Nullable)onCancelWithArguments:(id _Nullable)arguments {
+    resultSink = nil;
+    return nil;
+}
+
+- (FlutterError * _Nullable)onListenWithArguments:(id _Nullable)arguments eventSink:(nonnull FlutterEventSink)events {
+    resultSink = events;
+    return nil;
+}
+
 @end

lib/src/barcode_detector.dart

@@ -192,27 +192,24 @@ class BarcodeDetector {
   bool _isClosed = false;
 
   /// Detects barcodes in the input image.
-  Future<List<Barcode>> detectInImage(FirebaseVisionImage visionImage) async {
+  Stream<List<Barcode>> startDetection() {
     assert(!_isClosed);
 
     _hasBeenOpened = true;
-    final List<dynamic> reply =
-        await FirebaseVision.channel.invokeListMethod<dynamic>(
-      'BarcodeDetector#detectInImage',
+    Stream<dynamic> data = Stream.empty();
+    FirebaseVision.channel.invokeListMethod<dynamic>(
+      'BarcodeDetector#startDetection',
       <String, dynamic>{
         'handle': _handle,
         'options': <String, dynamic>{
           'barcodeFormats': options.barcodeFormats.value,
         },
-      }..addAll(visionImage._serialize()),
-    );
-
-    final List<Barcode> barcodes = <Barcode>[];
-    reply.forEach((dynamic barcode) {
-      barcodes.add(Barcode._(barcode));
+      },
+    ).then((onValue){
+      const EventChannel resultsChannel = EventChannel('plugins.flutter.io/firebase_mlvision_results');
+      data = resultsChannel.receiveBroadcastStream();
     });
-
-    return barcodes;
+    return data;
   }
 
   /// Release resources used by this detector.

lib/src/firebase_vision.dart

@@ -284,10 +284,11 @@ class FirebaseVision extends ValueNotifier<FirebaseCameraValue> {
   }
 
   /// Creates an instance of [BarcodeDetector].
-  BarcodeDetector barcodeDetector([BarcodeDetectorOptions options]) {
-    return BarcodeDetector._(options ?? const BarcodeDetectorOptions(),
+  Stream<List<Barcode>> addBarcodeDetector([BarcodeDetectorOptions options]) {
+    BarcodeDetector detector = BarcodeDetector._(options ?? const BarcodeDetectorOptions(),
     nextHandle++,
     );
+    return detector.startDetection();
   }
 
   /// Creates an instance of [VisionEdgeImageLabeler].