feat: add hasTorch function

@@ -19,6 +19,7 @@ Improvements:
 Features:
 * Added a new `placeholderBuilder` function to the `MobileScanner` widget to customize the preview placeholder.
 * Added `autoStart` parameter to MobileScannerController(). If set to false, controller won't start automatically.
+* Added `hasTorch` function on MobileScannerController(). After starting the controller, you can check if the device has a torch.
 
 Fixed:
 * Fixed a memory leak where the `MobileScanner` widget would never close its subscription to the barcode events.

@@ -101,6 +101,19 @@ class MobileScannerController {
 
   bool? _hasTorch;
 
+  /// Returns whether the device has a torch.
+  ///
+  /// Throws an error if the controller is not initialized.
+  bool get hasTorch {
+    if (_hasTorch == null) {
+      throw const MobileScannerException(
+        errorCode: MobileScannerErrorCode.controllerUninitialized,
+      );
+    }
+
+    return _hasTorch!;
+  }
+
   /// Set the starting arguments for the camera
   Map<String, dynamic> _argumentsToMap({CameraFacing? cameraFacingOverride}) {
     final Map<String, dynamic> arguments = {};