Updated updateDimensions and permissionCheck (#251)

ios/Classes/QRView.swift

@@ -77,222 +77,170 @@ public class QRView:NSObject,FlutterPlatformView {
         return previewView
     }
     
-    func setDimensions(_ result: @escaping FlutterResult, width: Double, height: Double, scanArea: Double, scanAreaOffset: Double) -> Void {
+    func requestPermissions(_ result: @escaping FlutterResult) {
         MTBBarcodeScanner.requestCameraPermission(success: { permissionGranted in
             if permissionGranted {
-//                self?.channel.invokeMethod("onPermissionSet", arguments: true)
-                // First set the size of the preview area.
-                self.previewView.frame = CGRect(x: 0, y: 0, width: width, height: height)
-                
-                // Then set the size of the scan area.
-                let midX = self.view().bounds.midX
-                let midY = self.view().bounds.midY
-                
-                // Check if the scanner is already created.
-                if let sc: MTBBarcodeScanner = self.scanner {
-                    if let previewLayer = sc.previewLayer {
-                        previewLayer.frame = self.previewView.bounds;
-                    }
-                    if (scanArea != 0) {
-                        sc.scanRect = CGRect(x: Double(midX) - (scanArea / 2), y: Double(midY) - (scanArea / 2), width: scanArea, height: scanArea)
-                        
-                        // Set offset if provided.
-                        if (scanAreaOffset != 0) {
-                            sc.scanRect = sc.scanRect.offsetBy(dx: 0, dy: CGFloat(scanAreaOffset))
-                        }
-                    }
-                } else {
-                    // Create a scanner view if it doesn't exist yet.
-                    self.scanner = MTBBarcodeScanner(previewView: self.previewView)
-                    
-                    if (scanArea != 0) {
-                        self.scanner?.didStartScanningBlock = {
-                            self.scanner?.scanRect = CGRect(x: Double(midX) - (scanArea / 2), y: Double(midY) - (scanArea / 2), width: scanArea, height: scanArea)
-                            
-                            // Set offset if provided.
-                            if (scanAreaOffset != 0) {
-                                self.scanner?.scanRect = (self.scanner?.scanRect.offsetBy(dx: 0, dy: CGFloat(scanAreaOffset)))!
-                            }
-                        }
-                    }
-                }
-                return result(width)
+                self.channel.invokeMethod("onPermissionSet", arguments: true)
             } else {
                 return result(FlutterError(code: "cameraPermission", message: "Permission denied to access the camera", details: nil))
             }
         })
     }
     
-    func startScan(_ arguments: Array<Int>, _ result: @escaping FlutterResult) -> Void {
-        if (scanner == nil) {
-            scanner = MTBBarcodeScanner(previewView: previewView)
+    func setDimensions(_ result: @escaping FlutterResult, width: Double, height: Double, scanArea: Double, scanAreaOffset: Double) {
+        // First ask for permission
+        requestPermissions(result)
+        
+        // Then set the size of the preview area.
+        self.previewView.frame = CGRect(x: 0, y: 0, width: width, height: height)
+        
+        // Then set the size of the scan area.
+        let midX = self.view().bounds.midX
+        let midY = self.view().bounds.midY
+        
+        // Check if the scanner already exists, else create one.
+        if (self.scanner == nil) {
+            self.scanner = MTBBarcodeScanner(previewView: self.previewView)
         }
         
+        // Set the size of the preview.
+        if let previewLayer = self.scanner?.previewLayer {
+            previewLayer.frame = self.previewView.bounds;
+        }
+        
+        // Set scanArea if provided.
+        if (scanArea != 0) {
+            self.scanner?.didStartScanningBlock = {
+                self.scanner?.scanRect = CGRect(x: Double(midX) - (scanArea / 2), y: Double(midY) - (scanArea / 2), width: scanArea, height: scanArea)
+
+                // Set offset if provided.
+                if (scanAreaOffset != 0) {
+                    self.scanner?.scanRect = (self.scanner?.scanRect.offsetBy(dx: 0, dy: CGFloat(scanAreaOffset)))!
+                }
+            }
+        }
+        return result(width)
+        
+    }
+    
+    func startScan(_ arguments: Array<Int>, _ result: @escaping FlutterResult) {
+        // Check for allowed barcodes
         var allowedBarcodeTypes: Array<AVMetadataObject.ObjectType> = []
         arguments.forEach { arg in
             allowedBarcodeTypes.append( QRCodeTypes[arg]!)
         }
         
-        MTBBarcodeScanner.requestCameraPermission(success: { permissionGranted in
-            if permissionGranted {
-                self.channel.invokeMethod("onPermissionSet", arguments: true)
-                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]
-                                if allowedBarcodeTypes.count == 0 || allowedBarcodeTypes.contains(code.type) {
-                                    self?.channel.invokeMethod("onRecognizeQR", arguments: result)
-                                }
-                                
-                            }
+        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]
+                        if allowedBarcodeTypes.count == 0 || allowedBarcodeTypes.contains(code.type) {
+                            self?.channel.invokeMethod("onRecognizeQR", arguments: result)
                         }
-                    })
-                } catch {
-                    let error = FlutterError(code: "unknown-error", message: "Unable to start scanning", details: nil)
-                    return result(error)
+                        
+                    }
                 }
-            } else {
-                return result(FlutterError(code: "cameraPermission", message: "Permission denied to access the camera", details: nil))
-            }
-        })
+            })
+        } catch {
+            let error = FlutterError(code: "unknown-error", message: "Unable to start scanning", details: nil)
+            return result(error)
+        }
     
     }
     
-    func stopCamera(_ result: @escaping FlutterResult){
-        MTBBarcodeScanner.requestCameraPermission(success: { permissionGranted in
-            if permissionGranted {
-                if let sc: MTBBarcodeScanner = self.scanner {
-                    if sc.isScanning() {
-                        sc.stopScanning()
-                    }
-                }
-            } else {
-                return result(FlutterError(code: "cameraPermission", message: "Permission denied to access the camera", details: nil))
+    func stopCamera(_ result: @escaping FlutterResult) {
+        if let sc: MTBBarcodeScanner = self.scanner {
+            if sc.isScanning() {
+                sc.stopScanning()
             }
-        })
+        }
     }
     
-    func getCameraInfo(_ result: @escaping FlutterResult) -> Void {
-        MTBBarcodeScanner.requestCameraPermission(success: { permissionGranted in
-            if permissionGranted {
-                result(self.cameraFacing.rawValue)
-            } else {
-                return result(FlutterError(code: "cameraPermission", message: "Permission denied to access the camera", details: nil))
-            }
-        })
+    func getCameraInfo(_ result: @escaping FlutterResult) {
+        result(self.cameraFacing.rawValue)
     }
     
-    func flipCamera(_ result: @escaping FlutterResult){
-        MTBBarcodeScanner.requestCameraPermission(success: { permissionGranted in
-            if permissionGranted {
-                if let sc: MTBBarcodeScanner = self.scanner {
-                    if sc.hasOppositeCamera() {
-                        sc.flipCamera()
-                        self.cameraFacing = sc.camera
-                    }
-                    return result(sc.camera.rawValue)
-                }
-                return result(FlutterError(code: "404", message: "No barcode scanner found", details: nil))
-            } else {
-                return result(FlutterError(code: "cameraPermission", message: "Permission denied to access the camera", details: nil))
+    func flipCamera(_ result: @escaping FlutterResult) {
+        if let sc: MTBBarcodeScanner = self.scanner {
+            if sc.hasOppositeCamera() {
+                sc.flipCamera()
+                self.cameraFacing = sc.camera
             }
-        })
+            return result(sc.camera.rawValue)
+        }
+        return result(FlutterError(code: "404", message: "No barcode scanner found", details: nil))
     }
     
-    func getFlashInfo(_ result: @escaping FlutterResult) -> Void {
-        MTBBarcodeScanner.requestCameraPermission(success: { permissionGranted in
-            if permissionGranted {
-                if let sc: MTBBarcodeScanner = self.scanner {
-                    result(sc.torchMode.rawValue != 0)
-                } else {
-                    let error = FlutterError(code: "cameraInformationError", message: "Could not get flash information", details: nil)
-                    result(error)
-                }
-            } else {
-                return result(FlutterError(code: "cameraPermission", message: "Permission denied to access the camera", details: nil))
-            }
-        })
+    func getFlashInfo(_ result: @escaping FlutterResult) {
+        if let sc: MTBBarcodeScanner = self.scanner {
+            result(sc.torchMode.rawValue != 0)
+        } else {
+            let error = FlutterError(code: "cameraInformationError", message: "Could not get flash information", details: nil)
+            result(error)
+        }
     }
     
     func toggleFlash(_ result: @escaping FlutterResult){
-        MTBBarcodeScanner.requestCameraPermission(success: { permissionGranted in
-            if permissionGranted {
-                if let sc: MTBBarcodeScanner = self.scanner {
-                    if sc.hasTorch() {
-                        sc.toggleTorch()
-                        return result(sc.torchMode == MTBTorchMode(rawValue: 1))
-                    }
-                    return result(FlutterError(code: "404", message: "This device doesn\'t support flash", details: nil))
-                }
-                return result(FlutterError(code: "404", message: "No barcode scanner found", details: nil))
-            } else {
-                return result(FlutterError(code: "cameraPermission", message: "Permission denied to access the camera", details: nil))
+        if let sc: MTBBarcodeScanner = self.scanner {
+            if sc.hasTorch() {
+                sc.toggleTorch()
+                return result(sc.torchMode == MTBTorchMode(rawValue: 1))
             }
-        })
+            return result(FlutterError(code: "404", message: "This device doesn\'t support flash", details: nil))
+        }
+        return result(FlutterError(code: "404", message: "No barcode scanner found", details: nil))
     }
     
     func pauseCamera(_ result: @escaping FlutterResult) {
-        MTBBarcodeScanner.requestCameraPermission(success: { permissionGranted in
-            if permissionGranted {
-                if let sc: MTBBarcodeScanner = self.scanner {
-                    if sc.isScanning() {
-                        sc.freezeCapture()
-                    }
-                    return result(true)
-                }
-                return result(FlutterError(code: "404", message: "No barcode scanner found", details: nil))
-            } else {
-                return result(FlutterError(code: "cameraPermission", message: "Permission denied to access the camera", details: nil))
+        if let sc: MTBBarcodeScanner = self.scanner {
+            if sc.isScanning() {
+                sc.freezeCapture()
             }
-        })
+            return result(true)
+        }
+        return result(FlutterError(code: "404", message: "No barcode scanner found", details: nil))
     }
     
     func resumeCamera(_ result: @escaping FlutterResult) {
-        MTBBarcodeScanner.requestCameraPermission(success: { permissionGranted in
-            if permissionGranted {
-                if let sc: MTBBarcodeScanner = self.scanner {
-                    if !sc.isScanning() {
-                        sc.unfreezeCapture()
-                    }
-                    return result(true)
-                }
-                return result(FlutterError(code: "404", message: "No barcode scanner found", details: nil))
-            } else {
-                return result(FlutterError(code: "cameraPermission", message: "Permission denied to access the camera", details: nil))
+        if let sc: MTBBarcodeScanner = self.scanner {
+            if !sc.isScanning() {
+                sc.unfreezeCapture()
             }
-        })
+            return result(true)
+        }
+        return result(FlutterError(code: "404", message: "No barcode scanner found", details: nil))
     }
 
-    func getSystemFeatures(_ result: @escaping FlutterResult) -> Void {
+    func getSystemFeatures(_ result: @escaping FlutterResult) {
         if let sc: MTBBarcodeScanner = scanner {
             var hasBackCameraVar = false
             var hasFrontCameraVar = false

lib/src/qr_code_scanner.dart

@@ -62,12 +62,10 @@ class _QRViewState extends State<QRView> {
   @override
   void initState() {
     super.initState();
-
-    WidgetsBinding.instance.addObserver(
-        LifecycleEventHandler(resumeCallBack: () async =>
-            QRViewController.updateDimensions(widget.key, _channel,
-            overlay: widget.overlay)
-    ));
+    WidgetsBinding.instance.addObserver(LifecycleEventHandler(
+        resumeCallBack: () async => QRViewController.updateDimensions(
+            widget.key, _channel,
+            overlay: widget.overlay)));
   }
 
   @override