add invoice pdf

lib/pages/invoice/invoice_table.dart

@@ -63,14 +63,14 @@ class InvoiceTable extends StatelessWidget {
   List<InvoiceTableRow> getTableRows() {
     List<InvoiceTableRow> tableRows = [];
     // add cargo types
-    List<CargoType> _cargoTypes = invoice.getCargoTypes(rate);
+    List<CargoType> _cargoTypes = invoice.getCargoTypes(rate) ?? [];
     _cargoTypes.forEach((c) {
       tableRows.add(InvoiceTableRow(
           invoiceDataType: InvoiceDataType.CargoDataType,
           desc: c.name,
           rate:
               "${c.calWeight.toStringAsFixed(2)} x ${c.calRate.toStringAsFixed(2)}",
-          amount: "${c.amount.toStringAsFixed(2)}"));
+          amount: "${c.calAmount.toStringAsFixed(2)}"));
     });
     invoice.shipments.where((ss) => (ss.isSelected ?? false)).forEach((s) {
       tableRows.add(InvoiceTableRow(
@@ -80,7 +80,7 @@ class InvoiceTable extends StatelessWidget {
           rate: "",
           amount: "${s.handlingFee.toStringAsFixed(2)}"));
     });
-    // add custom fee
+    // // add custom fee
     invoice.customDuties.forEach((c) {
       tableRows.add(InvoiceTableRow(
           data: c,
@@ -89,7 +89,7 @@ class InvoiceTable extends StatelessWidget {
           rate: "",
           amount: "${c.fee.toStringAsFixed(2)}"));
     });
-    // add delivery fee
+    // // add delivery fee
     tableRows.add(InvoiceTableRow(
         data: invoice.deliveryFee == null || invoice.deliveryFee == 0
             ? null
@@ -99,7 +99,7 @@ class InvoiceTable extends StatelessWidget {
         rate: "",
         amount: "${invoice?.deliveryFee?.toStringAsFixed(2) ?? '0'}"));
 
-    // add discounts
+    // // add discounts
     if (invoice.discount != null) {
       tableRows.add(InvoiceTableRow(
           data: invoice.discount,