Added possibility to choose facing camera on start.

Moved the size listener to plugin side.

android/src/main/kotlin/net/touchcapture/qr/flutterqr/QRView.kt

@@ -17,7 +17,7 @@ import io.flutter.plugin.common.BinaryMessenger
 import io.flutter.plugin.common.MethodCall
 import io.flutter.plugin.common.MethodChannel
 import io.flutter.plugin.platform.PlatformView
-class QRView(messenger: BinaryMessenger, id: Int, private val context: Context) :
+class QRView(messenger: BinaryMessenger, id: Int, private val context: Context, private val params: HashMap<String, Any>) :
         PlatformView, MethodChannel.MethodCallHandler {
 
     private var isTorchOn: Boolean = false
@@ -66,6 +66,12 @@ class QRView(messenger: BinaryMessenger, id: Int, private val context: Context)
 
     override fun onMethodCall(call: MethodCall, result: MethodChannel.Result) {
         when(call.method){
+            "startScan" -> {
+                startScan()
+            }
+            "stopScan" -> {
+                stopScan()
+            }
             "flipCamera" -> {
                 flipCamera()
             }
@@ -127,14 +133,16 @@ class QRView(messenger: BinaryMessenger, id: Int, private val context: Context)
 
     private fun initBarCodeView(): BarcodeView? {
         if (barcodeView == null) {
-            barcodeView = createBarCodeView()
+            barcodeView = BarcodeView(Shared.activity)
+            if (params["cameraFacing"] as Int == 1) {
+                barcodeView?.cameraSettings?.requestedCameraId = CameraInfo.CAMERA_FACING_FRONT
+            }
         }
         return barcodeView
     }
 
-    private fun createBarCodeView(): BarcodeView {
-        val barcode = BarcodeView(Shared.activity)
-        barcode.decodeContinuous(
+    private fun startScan() {
+        barcodeView?.decodeContinuous(
                 object : BarcodeCallback {
                     override fun barcodeResult(result: BarcodeResult) {
                         val code = mapOf(
@@ -147,7 +155,10 @@ class QRView(messenger: BinaryMessenger, id: Int, private val context: Context)
                     override fun possibleResultPoints(resultPoints: List<ResultPoint>) {}
                 }
         )
-        return barcode
+    }
+
+    private fun stopScan() {
+        barcodeView?.stopDecoding()
     }
 
     private fun hasCameraPermission(): Boolean {

android/src/main/kotlin/net/touchcapture/qr/flutterqr/QRViewFactory.kt

@@ -10,8 +10,9 @@ import io.flutter.plugin.platform.PlatformViewFactory
 class QRViewFactory(private val messenger: BinaryMessenger) :
         PlatformViewFactory(StandardMessageCodec.INSTANCE) {
 
-    override fun create(context: Context, id: Int, obj: Any?): PlatformView {
-        return QRView(messenger, id, context)
+    override fun create(context: Context, id: Int, args: Any?): PlatformView {
+        val params = args as HashMap<String, Any>
+        return QRView(messenger, id, context, params)
     }
 
 }

example/.gitignore

@@ -9,6 +9,7 @@
 .buildlog/
 .history
 .svn/
+.last_build_id
 
 # IntelliJ related
 *.iml

example/ios/Runner.xcodeproj/project.pbxproj

@@ -264,13 +264,11 @@
 			);
 			inputPaths = (
 				"${PODS_ROOT}/Target Support Files/Pods-Runner/Pods-Runner-frameworks.sh",
-				"${PODS_ROOT}/../Flutter/Flutter.framework",
 				"${BUILT_PRODUCTS_DIR}/MTBBarcodeScanner/MTBBarcodeScanner.framework",
 				"${BUILT_PRODUCTS_DIR}/qr_code_scanner/qr_code_scanner.framework",
 			);
 			name = "[CP] Embed Pods Frameworks";
 			outputPaths = (
-				"${TARGET_BUILD_DIR}/${FRAMEWORKS_FOLDER_PATH}/Flutter.framework",
 				"${TARGET_BUILD_DIR}/${FRAMEWORKS_FOLDER_PATH}/MTBBarcodeScanner.framework",
 				"${TARGET_BUILD_DIR}/${FRAMEWORKS_FOLDER_PATH}/qr_code_scanner.framework",
 			);

example/lib/main.dart

@@ -154,25 +154,18 @@ class _QRViewExampleState extends State<QRViewExample> {
         : 300.0;
     // To ensure the Scanner view is properly sizes after rotation
     // we need to listen for Flutter SizeChanged notification and update controller
-    return NotificationListener<SizeChangedLayoutNotification>(
-        onNotification: (notification) {
-          Future.microtask(
-              () => controller?.updateDimensions(qrKey, scanArea: scanArea));
-          return false;
-        },
-        child: SizeChangedLayoutNotifier(
-            key: const Key('qr-size-notifier'),
-            child: QRView(
-              key: qrKey,
-              onQRViewCreated: _onQRViewCreated,
-              overlay: QrScannerOverlayShape(
-                borderColor: Colors.red,
-                borderRadius: 10,
-                borderLength: 30,
-                borderWidth: 10,
-                cutOutSize: scanArea,
-              ),
-            )));
+    return QRView(
+      key: qrKey,
+      cameraFacing: CameraFacing.front,
+      onQRViewCreated: _onQRViewCreated,
+      overlay: QrScannerOverlayShape(
+        borderColor: Colors.red,
+        borderRadius: 10,
+        borderLength: 30,
+        borderWidth: 10,
+        cutOutSize: scanArea,
+      ),
+    );
   }
 
   void _onQRViewCreated(QRViewController controller) {

ios/Classes/QRView.swift

@@ -13,67 +13,28 @@ public class QRView:NSObject,FlutterPlatformView {
     var scanner: MTBBarcodeScanner?
     var registrar: FlutterPluginRegistrar
     var channel: FlutterMethodChannel
+    var cameraFacing: MTBCamera
     
-    public init(withFrame frame: CGRect, withRegistrar registrar: FlutterPluginRegistrar, withId id: Int64){
+    public init(withFrame frame: CGRect, withRegistrar registrar: FlutterPluginRegistrar, withId id: Int64, params: Dictionary<String, Any>){
         self.registrar = registrar
         previewView = UIView(frame: frame)
+        cameraFacing = MTBCamera.init(rawValue: UInt(Int(params["cameraFacing"] as! Double))) ?? MTBCamera.back
         channel = FlutterMethodChannel(name: "net.touchcapture.qr.flutterqr/qrview_\(id)", binaryMessenger: registrar.messenger())
     }
     
-    func isCameraAvailable(success: Bool) -> Void {
-        if success {
-            do {
-                try scanner?.startScanning(resultBlock: { [weak self] codes in
-                    if let codes = codes {
-                        for code in codes {
-                            var typeString: String;
-                            switch(code.type) {
-                                case AVMetadataObject.ObjectType.aztec:
-                                   typeString = "AZTEC"
-                                case AVMetadataObject.ObjectType.code39:
-                                    typeString = "CODE_39"
-                                case AVMetadataObject.ObjectType.code93:
-                                    typeString = "CODE_93"
-                                case AVMetadataObject.ObjectType.code128:
-                                    typeString = "CODE_128"
-                                case AVMetadataObject.ObjectType.dataMatrix:
-                                    typeString = "DATA_MATRIX"
-                                case AVMetadataObject.ObjectType.ean8:
-                                    typeString = "EAN_8"
-                                case AVMetadataObject.ObjectType.ean13:
-                                    typeString = "EAN_13"
-                                case AVMetadataObject.ObjectType.itf14:
-                                    typeString = "ITF"
-                                case AVMetadataObject.ObjectType.pdf417:
-                                    typeString = "PDF_417"
-                                case AVMetadataObject.ObjectType.qr:
-                                    typeString = "QR_CODE"
-                                case AVMetadataObject.ObjectType.upce:
-                                    typeString = "UPC_E"
-                                default:
-                                    return
-                            }
-                            guard let stringValue = code.stringValue else { continue }
-                            let result = ["code": stringValue, "type": typeString]
-                            self?.channel.invokeMethod("onRecognizeQR", arguments: result)
-                        }
-                    }
-                })
-            } catch {
-                NSLog("Unable to start scanning")
-            }
-        } else {
-            UIAlertView(title: "Scanning Unavailable", message: "This app does not have permission to access the camera", delegate: nil, cancelButtonTitle: nil, otherButtonTitles: "Ok").show()
-        }
+    deinit {
+        scanner?.stopScanning()
     }
     
     public func view() -> UIView {
         channel.setMethodCallHandler({
-            [weak self] (call: FlutterMethodCall, result: FlutterResult) -> Void in
+            [weak self] (call: FlutterMethodCall, result: @escaping FlutterResult) -> Void in
             switch(call.method){
                 case "setDimensions":
                     let arguments = call.arguments as! Dictionary<String, Double>
                     self?.setDimensions(width: arguments["width"] ?? 0, height: arguments["height"] ?? 0, scanArea: arguments["scanArea"] ?? 0)
+                case "startScan":
+                    self?.startScan(result)
                 case "flipCamera":
                     self?.flipCamera()
                 case "toggleFlash":
@@ -106,9 +67,67 @@ public class QRView:NSObject,FlutterPlatformView {
                     self.scanner?.scanRect = CGRect(x: Double(midX) - (scanArea / 2), y: Double(midY) - (scanArea / 2), width: scanArea, height: scanArea)
                 }
             }
-
-
-            MTBBarcodeScanner.requestCameraPermission(success: isCameraAvailable)
+        }
+    }
+    
+    func startScan(_ result: @escaping FlutterResult) -> Void {
+        scanner = MTBBarcodeScanner(previewView: previewView)
+        
+        MTBBarcodeScanner.requestCameraPermission(success: { permissionGranted in
+            if permissionGranted {
+                do {
+                    try self.scanner?.startScanning(with: self.cameraFacing, resultBlock: { [weak self] codes in
+                        if let codes = codes {
+                            for code in codes {
+                                var typeString: String;
+                                switch(code.type) {
+                                    case AVMetadataObject.ObjectType.aztec:
+                                       typeString = "AZTEC"
+                                    case AVMetadataObject.ObjectType.code39:
+                                        typeString = "CODE_39"
+                                    case AVMetadataObject.ObjectType.code93:
+                                        typeString = "CODE_93"
+                                    case AVMetadataObject.ObjectType.code128:
+                                        typeString = "CODE_128"
+                                    case AVMetadataObject.ObjectType.dataMatrix:
+                                        typeString = "DATA_MATRIX"
+                                    case AVMetadataObject.ObjectType.ean8:
+                                        typeString = "EAN_8"
+                                    case AVMetadataObject.ObjectType.ean13:
+                                        typeString = "EAN_13"
+                                    case AVMetadataObject.ObjectType.itf14:
+                                        typeString = "ITF"
+                                    case AVMetadataObject.ObjectType.pdf417:
+                                        typeString = "PDF_417"
+                                    case AVMetadataObject.ObjectType.qr:
+                                        typeString = "QR_CODE"
+                                    case AVMetadataObject.ObjectType.upce:
+                                        typeString = "UPC_E"
+                                    default:
+                                        return
+                                }
+                                guard let stringValue = code.stringValue else { continue }
+                                let result = ["code": stringValue, "type": typeString]
+                                self?.channel.invokeMethod("onRecognizeQR", arguments: result)
+                            }
+                        }
+                    })
+                } catch {
+                    let error = FlutterError(code: "unknown-error", message: "Unable to start scanning", details: nil)
+                    result(error)
+                }
+            } else {
+                let error = FlutterError(code: "cameraPermission", message: "Permission denied to access the camera", details: nil)
+                result(error)
+            }
+        })
+    }
+    
+    func stopScan(){
+        if let sc: MTBBarcodeScanner = scanner {
+            if sc.isScanning() {
+                sc.stopScanning()
+            }
         }
     }
     

ios/Classes/QRViewFactory.swift

@@ -17,8 +17,8 @@ public class QRViewFactory: NSObject, FlutterPlatformViewFactory {
     }
     
     public func create(withFrame frame: CGRect, viewIdentifier viewId: Int64, arguments args: Any?) -> FlutterPlatformView {
-        let dictionary =  args as! Dictionary<String, Double>
-        return QRView(withFrame: CGRect(x: 0, y: 0, width: dictionary["width"] ?? 0, height: dictionary["height"] ?? 0), withRegistrar: registrar!,withId: viewId)
+        let params = args as! Dictionary<String, Double>
+        return QRView(withFrame: frame, withRegistrar: registrar!,withId: viewId, params: params)
     }
     
     public func createArgsCodec() -> FlutterMessageCodec & NSObjectProtocol {

lib/src/qr_code_scanner.dart

@@ -7,6 +7,14 @@ import 'package:qr_code_scanner/qr_code_scanner.dart';
 
 typedef QRViewCreatedCallback = void Function(QRViewController);
 
+enum CameraFacing {
+  /// Shows back facing camera.
+  back,
+
+  /// Shows front facing camera.
+  front
+}
+
 enum BarcodeFormat {
   /// Aztec 2D barcode format.
   aztec,
@@ -80,6 +88,11 @@ const _formatNames = <String, BarcodeFormat>{
   'UPC_EAN_EXTENSION': BarcodeFormat.upcEanExtension,
 };
 
+/// The [Barcode] object holds information about the barcode or qr code.
+///
+/// [code] is the content of the barcode.
+/// [format] displays which type the code is.
+/// Only for Android, [rawBytes] gives a list of bytes of the result.
 class Barcode {
   Barcode(this.code, this.format, this.rawBytes);
 
@@ -90,60 +103,84 @@ class Barcode {
   final List<int> rawBytes;
 }
 
+/// The [QRView] is the view where the camera and the barcode scanner gets displayed.
 class QRView extends StatefulWidget {
   const QRView({
     @required Key key,
     @required this.onQRViewCreated,
     this.overlay,
     this.overlayMargin = EdgeInsets.zero,
+    this.cameraFacing = CameraFacing.back,
   })  : assert(key != null),
         assert(onQRViewCreated != null),
         super(key: key);
 
   final QRViewCreatedCallback onQRViewCreated;
-
   final ShapeBorder overlay;
   final EdgeInsetsGeometry overlayMargin;
+  final CameraFacing cameraFacing;
 
   @override
   State<StatefulWidget> createState() => _QRViewState();
 }
 
 class _QRViewState extends State<QRView> {
+
+  var _channel;
+
   @override
   Widget build(BuildContext context) {
+    return NotificationListener(
+      onNotification: onNotification,
+      child: SizeChangedLayoutNotifier(
+        child: (widget.overlay != null) ?
+        _getPlatformQrViewWithOverlay() :
+        _getPlatformQrView(),
+      ),
+    );
+  }
+
+  bool onNotification(notification) {
+    Future.microtask(() => {
+      QRViewController.updateDimensions(
+          widget.key,
+          _channel,
+    scanArea: widget.overlay != null ?
+    (widget.overlay as QrScannerOverlayShape).cutOutSize : 0.0)
+    });
+    return false;
+  }
+
+  Widget _getPlatformQrViewWithOverlay() {
     return Stack(
       children: [
-        _getPlatformQrView(widget.key),
-        if (widget.overlay != null)
-          Container(
-            padding: widget.overlayMargin,
-            decoration: ShapeDecoration(
-              shape: widget.overlay,
-            ),
-          )
-        else
-          Container(),
+        _getPlatformQrView(),
+        Container(
+          padding: widget.overlayMargin,
+          decoration: ShapeDecoration(
+            shape: widget.overlay,
+          ),
+        )
       ],
     );
   }
 
-  Widget _getPlatformQrView(GlobalKey key) {
+  Widget _getPlatformQrView() {
     Widget _platformQrView;
     switch (defaultTargetPlatform) {
       case TargetPlatform.android:
         _platformQrView = AndroidView(
           viewType: 'net.touchcapture.qr.flutterqr/qrview',
           onPlatformViewCreated: _onPlatformViewCreated,
+          creationParams: _QrCameraSettings(cameraFacing: widget.cameraFacing).toMap(),
+          creationParamsCodec: StandardMessageCodec(),
         );
         break;
       case TargetPlatform.iOS:
         _platformQrView = UiKitView(
           viewType: 'net.touchcapture.qr.flutterqr/qrview',
           onPlatformViewCreated: _onPlatformViewCreated,
-          creationParams:
-              _CreationParams.fromWidget(MediaQuery.of(context).size.width, 400)
-                  .toMap(),
+          creationParams: _QrCameraSettings(cameraFacing: widget.cameraFacing).toMap(),
           creationParamsCodec: StandardMessageCodec(),
         );
         break;
@@ -155,101 +192,109 @@ class _QRViewState extends State<QRView> {
   }
 
   void _onPlatformViewCreated(int id) {
-    if (widget.onQRViewCreated == null) {
-      return;
-    }
-
     // We pass the cutout size so that the scanner respects the scan area.
     var cutOutSize = 0.0;
     if (widget.overlay != null) {
       cutOutSize = (widget.overlay as QrScannerOverlayShape).cutOutSize;
     }
 
-    widget.onQRViewCreated(QRViewController._(id, widget.key, cutOutSize));
-  }
-}
+    _channel = MethodChannel('net.touchcapture.qr.flutterqr/qrview_$id');
 
-class _CreationParams {
-  _CreationParams({this.width, this.height});
+    // Start scan after creation of the view
+    final controller = QRViewController._(_channel, widget.key, cutOutSize)
+    .._startScan(widget.key, cutOutSize);
 
-  static _CreationParams fromWidget(double width, double height) {
-    return _CreationParams(
-      width: width,
-      height: height,
-    );
+    // Initialize the controller for controlling the QRView
+    if (widget.onQRViewCreated != null) {
+      widget.onQRViewCreated(controller);
+    }
   }
+}
+
+class _QrCameraSettings {
+  _QrCameraSettings({
+     this.cameraFacing,
+  });
 
-  final double width;
-  final double height;
+  final CameraFacing cameraFacing;
 
   Map<String, dynamic> toMap() {
     return <String, dynamic>{
-      'width': width,
-      'height': height,
+      'cameraFacing': cameraFacing.index,
     };
   }
+
 }
 
 class QRViewController {
-  QRViewController._(int id, GlobalKey qrKey, double scanArea)
-      : _channel = MethodChannel('net.touchcapture.qr.flutterqr/qrview_$id') {
-    updateDimensions(qrKey, scanArea: scanArea);
-    _channel.setMethodCallHandler(
-      (call) async {
-        switch (call.method) {
-          case scanMethodCall:
-            if (call.arguments != null) {
-              final args = call.arguments as Map;
-              final code = args['code'] as String;
-              final rawType = args['type'] as String;
-              // Raw bytes are only supported by Android.
-              final rawBytes = args['rawBytes'] as List<int>;
-              final format = _formatNames[rawType];
-              if (format != null) {
-                final barcode = Barcode(code, format, rawBytes);
-                _scanUpdateController.sink.add(barcode);
-              } else {
-                throw Exception('Unexpected barcode type $rawType');
-              }
-            }
-        }
-      },
-    );
+  QRViewController._(MethodChannel channel, GlobalKey qrKey, double scanArea)
+      : _channel = channel {
+    _channel.setMethodCallHandler(_onMethodCall);
   }
 
-  static const scanMethodCall = 'onRecognizeQR';
-
   final MethodChannel _channel;
-
   final StreamController<Barcode> _scanUpdateController =
       StreamController<Barcode>();
 
   Stream<Barcode> get scannedDataStream => _scanUpdateController.stream;
 
+  Future<void> _onMethodCall(MethodCall call) async {
+    switch (call.method) {
+      case 'onRecognizeQR':
+        if (call.arguments != null) {
+          final args = call.arguments as Map;
+          final code = args['code'] as String;
+          final rawType = args['type'] as String;
+          // Raw bytes are only supported by Android.
+          final rawBytes = args['rawBytes'] as List<int>;
+          final format = _formatNames[rawType];
+          if (format != null) {
+            final barcode = Barcode(code, format, rawBytes);
+            _scanUpdateController.sink.add(barcode);
+          } else {
+            throw Exception('Unexpected barcode type $rawType');
+          }
+        }
+    }
+  }
+
+  /// Starts the barcode scanner
+  Future<void> _startScan(GlobalKey key, double cutOutSize, ) async {
+    // We need to update the dimension before the scan is started.
+    QRViewController.updateDimensions(key, _channel, scanArea: cutOutSize);
+    return _channel.invokeMethod('startScan');
+  }
+
+  /// Flips the camera between available modes
   void flipCamera() {
     _channel.invokeMethod('flipCamera');
   }
 
+  /// Toggles the flashlight between available modes
   void toggleFlash() {
     _channel.invokeMethod('toggleFlash');
   }
 
+  /// Pauses barcode scanning
   void pauseCamera() {
     _channel.invokeMethod('pauseCamera');
   }
 
+  /// Resumes barcode scanning
   void resumeCamera() {
     _channel.invokeMethod('resumeCamera');
   }
 
+  /// Disposes the barcode stream.
   void dispose() {
     _scanUpdateController.close();
   }
 
-  void updateDimensions(GlobalKey key, {double scanArea}) {
+  /// Updates the view dimensions for iOS.
+  static void updateDimensions(GlobalKey key, MethodChannel channel, {double scanArea}) {
     if (defaultTargetPlatform == TargetPlatform.iOS) {
       final RenderBox renderBox = key.currentContext.findRenderObject();
-      _channel.invokeMethod('setDimensions', {
+      channel.invokeMethod('setDimensions', {
         'width': renderBox.size.width,
         'height': renderBox.size.height,
         'scanArea': scanArea ?? 0