define the platform interface

+import 'package:flutter/widgets.dart';
+import 'package:mobile_scanner/src/enums/camera_facing.dart';
 import 'package:mobile_scanner/src/method_channel/mobile_scanner_method_channel.dart';
+import 'package:mobile_scanner/src/mobile_scanner_view_attributes.dart';
 import 'package:plugin_platform_interface/plugin_platform_interface.dart';
 
 /// The platform interface for the `mobile_scanner` plugin.
@@ -22,4 +25,70 @@ abstract class MobileScannerPlatform extends PlatformInterface {
     PlatformInterface.verifyToken(instance, _token);
     _instance = instance;
   }
+
+  /// Analyze a local image file for barcodes.
+  ///
+  /// Returns whether the file at the given [path] contains a barcode.
+  Future<bool> analyzeImage(String path) {
+    throw UnimplementedError('analyzeImage() has not been implemented.');
+  }
+
+  /// Build the camera view for the barcode scanner.
+  Widget buildCameraView(covariant MobileScannerViewAttributes attributes) {
+    throw UnimplementedError('buildCameraView() has not been implemented.');
+  }
+
+  /// Dispose of this [MobileScannerPlatform] instance.
+  void dispose() {
+    throw UnimplementedError('dispose() has not been implemented.');
+  }
+
+  /// Reset the zoom scale, so that the camera is fully zoomed out.
+  Future<void> resetZoomScale() {
+    throw UnimplementedError('resetZoomScale() has not been implemented.');
+  }
+
+  /// Set the zoom scale of the camera.
+  ///
+  /// The [zoomScale] must be between `0.0` and `1.0` (both inclusive).
+  /// A value of `0.0` indicates that the camera is fully zoomed out,
+  /// while `1.0` indicates that the camera is fully zoomed in.
+  Future<void> setZoomScale(double zoomScale) {
+    throw UnimplementedError('setZoomScale() has not been implemented.');
+  }
+
+  /// Start scanning for barcodes.
+  ///
+  /// Upon calling this method, the necessary camera permission will be requested.
+  ///
+  /// Returns an instance of [MobileScannerViewAttributes].
+  Future<MobileScannerViewAttributes> start({CameraFacing? cameraDirection}) {
+    throw UnimplementedError('start() has not been implemented.');
+  }
+
+  /// Stop the camera.
+  Future<void> stop() {
+    throw UnimplementedError('stop() has not been implemented.');
+  }
+
+  /// Switch between the front and back camera.
+  Future<void> switchCamera() {
+    throw UnimplementedError('switchCamera() has not been implemented.');
+  }
+
+  /// Switch the torch on or off.
+  ///
+  /// Does nothing if the device has no torch.
+  Future<void> toggleTorch() {
+    throw UnimplementedError('toggleTorch() has not been implemented.');
+  }
+
+  /// Update the scan window to the given [window] rectangle.
+  ///
+  /// Any barcodes that do not intersect with the given [window] will be ignored.
+  ///
+  /// If [window] is `null`, the scan window will be reset to the full screen.
+  Future<void> updateScanWindow(Rect? window) {
+    throw UnimplementedError('updateScanWindow() has not been implemented.');
+  }
 }