null safety

lib/pages/invoice/payment/payment_page.dart

@@ -20,8 +20,8 @@ import 'package:intl/intl.dart';
 import 'package:provider/provider.dart';
 
 class PaymentPage extends StatefulWidget {
-  final Invoice invoice;
-  final bool forCustomer;
+  final Invoice? invoice;
+  final bool? forCustomer;
   PaymentPage({this.invoice, this.forCustomer});
 
   @override
@@ -35,15 +35,15 @@ class _PaymentPageState extends State<PaymentPage> {
   Invoice _invoice = new Invoice();
   bool _isLoading = false;
 
-  bool isNew;
-  File _file;
-  bool _hasBalance;
+  bool isNew = false;
+  File? _file;
+  bool _hasBalance = false;
 
   @override
   void initState() {
     super.initState();
-    _invoice = widget.invoice;
-    _hasBalance = widget.invoice.balance > 0;
+    _invoice = widget.invoice!;
+    _hasBalance = widget.invoice!.balance > 0;
     _loadInvoice();
   }
 
@@ -129,7 +129,7 @@ class _PaymentPageState extends State<PaymentPage> {
   getCustomFeeRows(BuildContext context) {
     List<Widget> dataRow = [];
 
-    dataRow = _invoice?.payments?.map((p) {
+    dataRow = _invoice.payments.map((p) {
           return Container(
             decoration: BoxDecoration(
                 border: Border(bottom: BorderSide(color: Colors.grey))),
@@ -165,7 +165,7 @@ class _PaymentPageState extends State<PaymentPage> {
                         child: Column(
                       children: [Text('\$ ${p.amount}'), Text('${p.status}')],
                     ))),
-                widget.forCustomer
+                widget.forCustomer!
                     ? Container()
                     : Expanded(
                         flex: 1,
@@ -197,8 +197,7 @@ class _PaymentPageState extends State<PaymentPage> {
               ],
             ),
           );
-        })?.toList() ??
-        [];
+        }).toList() ;
 
     dataRow.insert(
         0,
@@ -217,7 +216,7 @@ class _PaymentPageState extends State<PaymentPage> {
                   child: Text('Amount',
                       textAlign: TextAlign.center,
                       style: TextStyle(color: Colors.grey))),
-              widget.forCustomer
+              widget.forCustomer!
                   ? Container()
                   : Expanded(
                       flex: 1,
@@ -250,11 +249,11 @@ class _PaymentPageState extends State<PaymentPage> {
                   flex: 1,
                   child: Center(
                       child: Text(
-                          '\$ ${widget.invoice.balance.toStringAsFixed(2)}',
+                          '\$ ${widget.invoice!.balance.toStringAsFixed(2)}',
                           textAlign: TextAlign.center,
                           style: TextStyle(
                               fontWeight: FontWeight.bold, fontSize: 16.0)))),
-              widget.forCustomer
+              widget.forCustomer!
                   ? Container()
                   : Expanded(
                       flex: 1,
@@ -279,7 +278,7 @@ class _PaymentPageState extends State<PaymentPage> {
   }
 
   _updatePayment(Payment payment) async {
-    payment.invoiceID = widget.invoice.id;
+    payment.invoiceID = widget.invoice!.id;
     setState(() {
       _isLoading = true;
     });
@@ -314,7 +313,7 @@ class _PaymentPageState extends State<PaymentPage> {
     try {
       InvoiceModel invoiceModel =
           Provider.of<InvoiceModel>(context, listen: false);
-      await invoiceModel.pay(payment, _file);
+      await invoiceModel.pay(payment, _file!);
       Navigator.pop(context, true);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());

lib/pages/invoice/payment/payment_page_edit.dart

@@ -20,7 +20,7 @@ import 'package:intl/intl.dart';
 import 'package:provider/provider.dart';
 
 class PaymentPageEdit extends StatefulWidget {
-  final Receipt receipt;
+  final Receipt? receipt;
   PaymentPageEdit({this.receipt});
 
   @override
@@ -33,14 +33,14 @@ class _PaymentPageEditState extends State<PaymentPageEdit> {
 
   Receipt _receipt = new Receipt();
   bool _isLoading = false;
-  File _file;
+  File? _file;
 
-  bool isNew;
+  bool isNew = false;
 
   @override
   void initState() {
     if (widget.receipt != null) {
-      _receipt = widget.receipt;
+      _receipt = widget.receipt!;
     }
     super.initState();
   }
@@ -185,11 +185,11 @@ class _PaymentPageEditState extends State<PaymentPageEdit> {
       return initialImage();
     } else {
       Widget _widget;
-      if (widget.receipt.fileUrl == null) {
+      if (widget.receipt!.fileUrl == null) {
         _widget = initialImage();
       } else {
         _widget = InkWell(
-          child: Image.asset(widget.receipt.fileUrl, fit: BoxFit.cover),
+          child: Image.asset(widget.receipt!.fileUrl, fit: BoxFit.cover),
           onTap: () {},
         );
       }
@@ -209,13 +209,13 @@ class _PaymentPageEditState extends State<PaymentPageEdit> {
 
   Widget enableUpload(BuildContext context) {
     return InkWell(
-      child: Image.file(_file, fit: BoxFit.cover),
+      child: Image.file(_file!, fit: BoxFit.cover),
       onTap: () {
         Navigator.push(
             context,
             MaterialPageRoute(
                 builder: (context) =>
-                    ShowImage(imageFile: _file, url: null, fileName: 'image')));
+                    ShowImage(imageFile: _file!, url: '', fileName: 'image')));
       },
     );
   }