add size attribute to BarcodeCapture; make width/height of barcode capture non-null

@@ -7,6 +7,8 @@ Improvements:
 * The `phones` and `urls` of `ContactInfo` are now non-null.
 * The `url` of a `UrlBookmark` is now non-null.
 * The `type` of `Phone` is now non-null.
+* The `width` and `height` of `BarcodeCapture` are now non-null.
+* The `BarcodeCapture` class now exposes a `size`.
 
 ## 3.5.0
 New Features:

 import 'dart:typed_data';
+import 'dart:ui';
 
 import 'package:mobile_scanner/src/objects/barcode.dart';
 
-/// The return object after a frame is scanned.
-///
-/// [barcodes] A list with barcodes. A scanned frame can contain multiple
-/// barcodes.
-/// [image] If enabled, an image of the scanned frame.
+/// This class represents a scanned barcode.
 class BarcodeCapture {
+  /// Create a new [BarcodeCapture] instance.
+  BarcodeCapture({
+    this.barcodes = const <Barcode>[],
+    double? height,
+    this.image,
+    this.raw,
+    double? width,
+  }) : size =
+            width == null && height == null ? Size.zero : Size(width!, height!);
+
+  /// The list of scanned barcodes.
   final List<Barcode> barcodes;
-  final dynamic raw;
 
+  /// The bytes of the image that is embedded in the barcode.
+  ///
+  /// This null if [MobileScannerController.returnImage] is false.
   final Uint8List? image;
 
-  final double? width;
+  /// The raw data of the scanned barcode.
+  final dynamic raw; // TODO: this should be `Object?` instead of dynamic
 
-  final double? height;
+  /// The size of the scanned barcode.
+  final Size size;
 
-  BarcodeCapture({
-    required this.barcodes,
-    required this.raw,
-    this.image,
-    this.width,
-    this.height,
-  });
+  /// The width of the scanned barcode.
+  ///
+  /// Prefer using `size.width` instead,
+  /// as this getter will be removed in the future.
+  double get width => size.width;
+
+  /// The height of the scanned barcode.
+  ///
+  /// Prefer using `size.height` instead,
+  /// as this getter will be removed in the future.
+  double get height => size.height;
 }