add hasTorch & setTorchState to the barcode reader interface instead

@@ -4,19 +4,16 @@ import 'dart:ui';
 
 import 'package:js/js.dart';
 import 'package:mobile_scanner/src/enums/mobile_scanner_error_code.dart';
+import 'package:mobile_scanner/src/enums/torch_state.dart';
 import 'package:mobile_scanner/src/mobile_scanner_exception.dart';
 import 'package:mobile_scanner/src/objects/barcode_capture.dart';
 import 'package:mobile_scanner/src/objects/start_options.dart';
-import 'package:mobile_scanner/src/web/flashlight_delegate.dart';
 import 'package:web/web.dart';
 
 /// This class represents the base interface for a barcode reader implementation.
 abstract class BarcodeReader {
   const BarcodeReader();
 
-  /// Get the flashlight delegate for the barcode reader.
-  FlashlightDelegate get flashlightDelegate => const FlashlightDelegate();
-
   /// Whether the scanner is currently scanning for barcodes.
   bool get isScanning {
     throw UnimplementedError('isScanning has not been implemented.');
@@ -45,6 +42,11 @@ abstract class BarcodeReader {
     throw UnimplementedError('detectBarcodes() has not been implemented.');
   }
 
+  /// Check whether the active camera has a flashlight.
+  Future<bool> hasTorch() {
+    throw UnimplementedError('hasTorch() has not been implemented.');
+  }
+
   /// Load the barcode reader library.
   ///
   /// Does nothing if the library is already loaded.
@@ -93,6 +95,11 @@ abstract class BarcodeReader {
     await completer.future;
   }
 
+  /// Set the torch state for the active camera to the given [value].
+  Future<void> setTorchState(TorchState value) {
+    throw UnimplementedError('setTorchState() has not been implemented.');
+  }
+
   /// Start the barcode reader and initialize the video stream.
   ///
   /// The [options] are used to configure the barcode reader.

@@ -115,12 +115,10 @@ class MobileScannerWeb extends MobileScannerPlatform {
         _barcodesController.add(barcode);
       });
 
-      final bool hasTorch = _barcodeReader.hasTorch;
+      final bool hasTorch = await _barcodeReader.hasTorch();
 
       if (hasTorch && startOptions.torchEnabled) {
-        await _barcodeReader.setTorchState(TorchState.on).catchError((_) {
-          // If the torch could not be turned on, continue the camera session anyway.
-        });
+        await _barcodeReader.setTorchState(TorchState.on);
       }
 
       return MobileScannerViewAttributes(