fix(ios): fix torch

@@ -12,6 +12,7 @@ import MLKitVision
 import MLKitBarcodeScanning
 
 typealias MobileScannerCallback = ((Array<Barcode>?, Error?, UIImage) -> ())
+typealias TorchModeChangeCallback = ((Int?) -> ())
 
 public class MobileScanner: NSObject, AVCaptureVideoDataOutputSampleBufferDelegate, FlutterTexture {
     /// Capture session of the camera
@@ -32,6 +33,9 @@ public class MobileScanner: NSObject, AVCaptureVideoDataOutputSampleBufferDelega
     /// When results are found, this callback will be called
     let mobileScannerCallback: MobileScannerCallback
 
+    /// When torch mode is changes, this callback will be called
+    let torchModeChangeCallback: TorchModeChangeCallback
+
     /// If provided, the Flutter registry will be used to send the output of the CaptureOutput to a Flutter texture.
     private let registry: FlutterTextureRegistry?
 
@@ -43,9 +47,10 @@ public class MobileScanner: NSObject, AVCaptureVideoDataOutputSampleBufferDelega
 
     var detectionSpeed: DetectionSpeed = DetectionSpeed.noDuplicates
 
-    init(registry: FlutterTextureRegistry?, mobileScannerCallback: @escaping MobileScannerCallback) {
+    init(registry: FlutterTextureRegistry?, mobileScannerCallback: @escaping MobileScannerCallback, torchModeChangeCallback: @escaping TorchModeChangeCallback) {
         self.registry = registry
         self.mobileScannerCallback = mobileScannerCallback
+        self.torchModeChangeCallback = torchModeChangeCallback
         super.init()
     }
 
@@ -207,6 +212,18 @@ public class MobileScanner: NSObject, AVCaptureVideoDataOutputSampleBufferDelega
         }
     }
 
+    // Observer for torch state
+    public override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
+        switch keyPath {
+        case "torchMode":
+            // off = 0; on = 1; auto = 2;
+            let state = change?[.newKey] as? Int
+            torchModeChangeCallback(state)
+        default:
+            break
+        }
+    }
+
     /// Analyze a single image
     func analyzeImage(image: UIImage, position: AVCaptureDevice.Position, callback: @escaping BarcodeScanningCallback) {
         let image = VisionImage(image: image)

@@ -23,6 +23,8 @@ public class SwiftMobileScannerPlugin: NSObject, FlutterPlugin {
             } else if (error != nil){
                 barcodeHandler.publishEvent(["name": "error", "data": error!.localizedDescription])
             }
+        }, torchModeChangeCallback: { torchState in
+            barcodeHandler.publishEvent(["name": "torchState", "data": torchState])
         })
         self.barcodeHandler = barcodeHandler
         super.init()
@@ -145,16 +147,4 @@ public class SwiftMobileScannerPlugin: NSObject, FlutterPlugin {
         })
         result(nil)
     }
-    
-    /// Observer for torch state
-    public override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
-        switch keyPath {
-        case "torchMode":
-            // off = 0; on = 1; auto = 2;
-            let state = change?[.newKey] as? Int
-            barcodeHandler.publishEvent(["name": "torchState", "data": state])
-        default:
-            break
-        }
-    }
 }