fix macos build error

@@ -108,7 +108,7 @@ public class MobileScannerPlugin: NSObject, FlutterPlugin, FlutterStreamHandler,
         latestBuffer = imageBuffer
         registry.textureFrameAvailable(textureId)
         
-        let currentTime = Date.now.timeIntervalSince1970
+        let currentTime = Date().timeIntervalSince1970
         let eligibleForScan = currentTime > nextScanTime && imagesCurrentlyBeingProcessed == 0;
         if ((detectionSpeed == DetectionSpeed.normal || detectionSpeed == DetectionSpeed.noDuplicates) && eligibleForScan || detectionSpeed == DetectionSpeed.unrestricted) {
             nextScanTime = currentTime + timeoutSeconds
@@ -118,7 +118,7 @@ public class MobileScannerPlugin: NSObject, FlutterPlugin, FlutterStreamHandler,
                 orientation: .right)
             
                 do {
-                  try imageRequestHandler.perform([VNDetectBarcodesRequest { (request, error) in
+                  try imageRequestHandler.perform([VNDetectBarcodesRequest { [self] (request, error) in
                     imagesCurrentlyBeingProcessed -= 1
                       if error == nil {
                           if let results = request.results as? [VNBarcodeObservation] {
@@ -226,7 +226,7 @@ public class MobileScannerPlugin: NSObject, FlutterPlugin, FlutterStreamHandler,
         let speed: Int = (call.arguments as! Dictionary<String, Any?>)["speed"] as? Int ?? 0
         let timeoutMs: Int = (call.arguments as! Dictionary<String, Any?>)["timeout"] as? Int ?? 0
 
-        timeoutSeconds = timeoutMs * 1000.0
+        timeoutSeconds = Double(timeoutMs) * 1000.0
         detectionSpeed = DetectionSpeed(rawValue: speed)!
 
         // Set the camera to use