added id to task

lib/model/latlng.dart

@@ -0,0 +1,7 @@
+class LatLng {
+  final double lat;
+  final double lng;
+
+  LatLng(this.lat, this.lng);
+  LatLng.empty() : lat = 0, lng = 0;
+}

lib/model/location.dart

@@ -0,0 +1,14 @@
+import 'latlng.dart';
+
+class Location {
+  final String? _address;
+  final LatLng? _coordinates;
+
+  Location({this._address, this._coordinates});
+
+  Location.fromAddress({required this._address}) : _coordinates = null;
+  Location.fromCoordinates({required this._coordinates}) : _address = null;
+
+  String get address => _address ?? '';
+  LatLng get coordinates => _coordinates ?? LatLng.empty();
+}

lib/model/task.dart

@@ -0,0 +1,29 @@
+import 'location.dart';
+
+class Task {
+  final String id;
+  final String title;
+  final String description;
+  final DateTime? start;
+  final DateTime? due;
+  final bool isCompleted;
+  final String category;
+  final List<Task> subtasks;
+  final List<DateTime> alarms;
+  final Location? location;
+  final String url;
+
+  Task({
+    required this.id,
+    required this.title,
+    this.description = '',
+    this.start,
+    this.due,
+    this.isCompleted = false,
+    this.category = '',
+    this.subtasks = const [],
+    this.alarms = const [],
+    this.location,
+    this.url = '',
+  });
+}