null safety

lib/pages/shipment/shipment_confirm.dart

@@ -8,14 +8,15 @@ import 'package:fcs/pages/widgets/local_text.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_icons_null_safety/flutter_icons_null_safety.dart';
+import 'package:font_awesome_flutter/font_awesome_flutter.dart';
 import 'package:intl/intl.dart';
 import 'package:provider/provider.dart';
 
 import 'widgets.dart';
 
 class ShipmentConfirm extends StatefulWidget {
-  final Shipment shipment;
+  final Shipment? shipment;
   ShipmentConfirm({this.shipment});
 
   @override
@@ -27,7 +28,7 @@ class _ShipmentConfirmState extends State<ShipmentConfirm> {
   var timeFormatter = new DateFormat('jm');
   TextEditingController _handlingFee = new TextEditingController();
 
-  Shipment _shipment;
+  Shipment? _shipment;
   bool _isLoading = false;
   var now = new DateTime.now();
 
@@ -36,17 +37,17 @@ class _ShipmentConfirmState extends State<ShipmentConfirm> {
     super.initState();
 
     _shipment = widget.shipment;
-    _handlingFee.text = _shipment.handlingFee?.toString() ?? "0";
+    _handlingFee.text = _shipment!.handlingFee?.toString() ?? "0";
   }
 
   @override
   Widget build(BuildContext context) {
-    final shipmentNumberBox = getShipmentNumberStatus(context, _shipment);
+    final shipmentNumberBox = getShipmentNumberStatus(context, _shipment!);
 
     final handlingFeeBox = InputText(
       labelTextKey: "shipment.handling.fee",
       controller: _handlingFee,
-      iconData: FontAwesome.truck,
+      iconData: FontAwesomeIcons.truck,
     );
     final confirmbtn = LocalButton(
       textKey: "shipment.confirm.btn",
@@ -94,14 +95,14 @@ class _ShipmentConfirmState extends State<ShipmentConfirm> {
   }
 
   _save() async {
-    _shipment.handlingFee = double.tryParse(_handlingFee.text) ?? 0;
+    _shipment!.handlingFee = double.tryParse(_handlingFee.text) ?? 0;
     setState(() {
       _isLoading = true;
     });
     try {
       ShipmentModel shipmentModel =
           Provider.of<ShipmentModel>(context, listen: false);
-      await shipmentModel.confirmShipment(_shipment);
+      await shipmentModel.confirmShipment(_shipment!);
       Navigator.pop(context, true);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());