move CalendarEvent to its own file

@@ -14,6 +14,7 @@ export 'src/mobile_scanner_controller.dart';
 export 'src/mobile_scanner_exception.dart';
 export 'src/objects/barcode.dart';
 export 'src/objects/barcode_capture.dart';
+export 'src/objects/calendar_event.dart';
 export 'src/objects/driver_license.dart';
 export 'src/objects/email.dart';
 export 'src/objects/mobile_scanner_arguments.dart';

@@ -7,6 +7,7 @@ import 'package:mobile_scanner/src/enums/barcode_format.dart';
 import 'package:mobile_scanner/src/enums/barcode_type.dart';
 import 'package:mobile_scanner/src/enums/encryption_type.dart';
 import 'package:mobile_scanner/src/enums/phone_type.dart';
+import 'package:mobile_scanner/src/objects/calendar_event.dart';
 import 'package:mobile_scanner/src/objects/driver_license.dart';
 import 'package:mobile_scanner/src/objects/email.dart';
 
@@ -118,58 +119,6 @@ class Barcode {
         wifi = toWiFi(data['wifi'] as Map?);
 }
 
-/// A calendar event extracted from QRCode.
-class CalendarEvent {
-  /// Gets the description of the calendar event.
-  ///
-  /// Returns null if not available.
-  final String? description;
-
-  /// Gets the start date time of the calendar event.
-  ///
-  /// Returns null if not available.
-  final DateTime? start;
-
-  /// Gets the end date time of the calendar event.
-  ///
-  /// Returns null if not available.
-  final DateTime? end;
-
-  /// Gets the location of the calendar event.
-  ///
-  /// Returns null if not available.
-  final String? location;
-
-  /// Gets the organizer of the calendar event.
-  ///
-  /// Returns null if not available.
-  final String? organizer;
-
-  /// Gets the status of the calendar event.
-  ///
-  /// Returns null if not available.
-  final String? status;
-
-  /// Gets the summary of the calendar event.
-  ///
-  /// Returns null if not available.
-  final String? summary;
-
-  /// Create a [CalendarEvent] from native data.
-  CalendarEvent.fromNative(Map data)
-      : description = data['description'] as String?,
-        start = data['start'] != null
-            ? DateTime.tryParse(data['start'] as String)
-            : null,
-        end = data['end'] != null
-            ? DateTime.tryParse(data['end'] as String)
-            : null,
-        location = data['location'] as String?,
-        organizer = data['organizer'] as String?,
-        status = data['status'] as String?,
-        summary = data['summary'] as String?;
-}
-
 /// A person's or organization's business card. For example a VCARD.
 class ContactInfo {
   /// Gets contact person's addresses.

+/// A calendar event extracted from a QRCode.
+class CalendarEvent {
+  /// Create a new [CalendarEvent] instance.
+  const CalendarEvent({
+    this.description,
+    this.start,
+    this.end,
+    this.location,
+    this.organizer,
+    this.status,
+    this.summary,
+  });
+
+  /// Create a new [CalendarEvent] instance from a map.
+  factory CalendarEvent.fromNative(Map<Object?, Object?> data) {
+    return CalendarEvent(
+      description: data['description'] as String?,
+      start: DateTime.tryParse(data['start'] as String? ?? ''),
+      end: DateTime.tryParse(data['end'] as String? ?? ''),
+      location: data['location'] as String?,
+      organizer: data['organizer'] as String?,
+      status: data['status'] as String?,
+      summary: data['summary'] as String?,
+    );
+  }
+
+  /// The description of the calendar event.
+  final String? description;
+
+  /// The start time of the calendar event.
+  final DateTime? start;
+
+  /// The end time of the calendar event.
+  final DateTime? end;
+
+  /// The location of the calendar event.
+  final String? location;
+
+  /// The organizer of the calendar event.
+  final String? organizer;
+
+  /// The status of the calendar event.
+  final String? status;
+
+  /// The summary of the calendar event.
+  final String? summary;
+}