null safety

lib/pages/carton/carton_row.dart

@@ -2,15 +2,15 @@ import 'package:fcs/domain/entities/carton.dart';
 import 'package:fcs/helpers/theme.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:intl/intl.dart';
 
 typedef OnRemove(Carton carton);
 
 class CartonRow extends StatelessWidget {
-  final Carton box;
-  final OnRemove onRemove;
-  CartonRow({Key key, this.box, this.onRemove}) : super(key: key);
+  final Carton? box;
+  final OnRemove? onRemove;
+  CartonRow({Key? key, this.box, this.onRemove}) : super(key: key);
 
   final double dotSize = 15.0;
   final DateFormat dateFormat = new DateFormat("dd MMM yyyy");
@@ -20,7 +20,7 @@ class CartonRow extends StatelessWidget {
     return Container(
       decoration: BoxDecoration(
         border: Border(
-          bottom: BorderSide(color: Colors.grey[300]),
+          bottom: BorderSide(color: Colors.grey.shade300),
         ),
       ),
       child: Row(
@@ -45,7 +45,7 @@ class CartonRow extends StatelessWidget {
                         Padding(
                           padding: const EdgeInsets.only(left: 8.0),
                           child: new Text(
-                            box.cartonNumber ?? "",
+                            box!.cartonNumber,
                             style: new TextStyle(
                                 fontSize: 15.0, color: Colors.black),
                           ),
@@ -53,7 +53,7 @@ class CartonRow extends StatelessWidget {
                         Padding(
                           padding: const EdgeInsets.only(left: 10.0, top: 10),
                           child: new Text(
-                            box.userName ?? "",
+                            box!.userName,
                             style: new TextStyle(
                                 fontSize: 15.0, color: Colors.grey),
                           ),
@@ -75,16 +75,16 @@ class CartonRow extends StatelessWidget {
                         color: primaryColor,
                       ),
                       onPressed: () {
-                        if (onRemove != null) onRemove(box);
+                        if (onRemove != null) onRemove!(box!);
                       }),
-              box.actualWeight == 0
+              box!.actualWeight == 0
                   ? Container()
                   : Padding(
                       padding: const EdgeInsets.only(left: 8.0, bottom: 5),
                       child: Row(
                         children: <Widget>[
                           new Text(
-                            "${box.actualWeight?.toStringAsFixed(2) ?? ''} lb",
+                            "${box!.actualWeight.toStringAsFixed(2)} lb",
                             style: new TextStyle(
                                 fontSize: 15.0, color: Colors.grey),
                           ),