fix null safety

lib/pages/package/model/package_model.dart

@@ -16,9 +16,9 @@ import 'package:path/path.dart' as Path;
 class PackageModel extends BaseModel {
   final log = Logger('PackageModel');
 
-  late PaginatorListener<Package> packages;
-  late PaginatorListener<Package> customerPackages;
-  late PaginatorListener<Package> activePackages;
+  PaginatorListener<Package>? packages;
+  PaginatorListener<Package>? customerPackages;
+  PaginatorListener<Package>? activePackages;
 
   bool isLoading = false;
   int _menuSelectedIndex = 1;
@@ -63,9 +63,9 @@ class PackageModel extends BaseModel {
 
   @override
   logout() async {
-    if (customerPackages != null) customerPackages.close();
-    if (packages != null) packages.close();
-    if (activePackages != null) activePackages.close();
+    if (customerPackages != null) customerPackages!.close();
+    if (packages != null) packages!.close();
+    if (activePackages != null) activePackages!.close();
   }
 
   Future<void> _loadPackages(bool isDelivered) async {
@@ -84,7 +84,7 @@ class PackageModel extends BaseModel {
           .where("is_delivered", isEqualTo: isDelivered);
 
       pageQuery = pageQuery.orderBy("update_time", descending: true);
-      packages.refresh(listeningQuery: listenerQuery, pageQuery: pageQuery);
+      packages!.refresh(listeningQuery: listenerQuery, pageQuery: pageQuery);
     } catch (e) {
       log.warning("Error!! $e");
     }
@@ -105,8 +105,8 @@ class PackageModel extends BaseModel {
           .where("user_id", isEqualTo: user!.id)
           .orderBy("update_time", descending: true);
 
-      customerPackages.refresh(
-          listeningQuery: listenerQuery, pageQuery: pageQuery);
+      customerPackages!
+          .refresh(listeningQuery: listenerQuery, pageQuery: pageQuery);
     } catch (e) {
       log.warning("Error!! $e");
     }
@@ -128,8 +128,8 @@ class PackageModel extends BaseModel {
           .where("is_delivered", isEqualTo: false);
 
       pageQuery = pageQuery.orderBy("update_time", descending: true);
-      activePackages.refresh(
-          listeningQuery: listenerQuery, pageQuery: pageQuery);
+      activePackages!
+          .refresh(listeningQuery: listenerQuery, pageQuery: pageQuery);
     } catch (e) {
       log.warning("Error!! $e");
     }
@@ -163,8 +163,7 @@ class PackageModel extends BaseModel {
           .get(const GetOptions(source: Source.server));
       if (snaps.docs.length == 1) {
         var snap = snaps.docs[0];
-        var package =
-            Package.fromMap(snap.data as Map<String, dynamic>, snap.id);
+        var package = Package.fromMap(snap.data(), snap.id);
         return package;
       }
     } catch (e) {

lib/pages/package/package_info.dart

@@ -38,7 +38,7 @@ class PackageInfo extends StatefulWidget {
 
 class _PackageInfoState extends State<PackageInfo> {
   var dateFormatter = new DateFormat('dd MMM yyyy');
-  Package? _package;
+  Package? _package = Package();
   bool _isLoading = false;
   MultiImgController multiImgController = MultiImgController();
 
@@ -48,13 +48,19 @@ class _PackageInfoState extends State<PackageInfo> {
     initPackage(widget.package!);
   }
 
-  initPackage(Package pkg) async {
+  initPackage(Package? pkg) async {
+    setState(() {
+      _isLoading = true;
+    });
+    if (pkg == null) return;
     PackageModel packageModel =
         Provider.of<PackageModel>(context, listen: false);
-    Package? package = await packageModel.getPackageByTrackingID(pkg.trackingID!);
+    Package? package =
+        await packageModel.getPackageByTrackingID(pkg!.trackingID!);
     setState(() {
       _package = package;
       multiImgController.setImageUrls = package!.photoUrls;
+      _isLoading = false;
     });
   }
 

lib/pages/package/package_list.dart

@@ -84,7 +84,7 @@ class _PackageListState extends State<PackageList> {
             ],
           ),
           body: PaginatorListView<Package>(
-            paginatorListener: packages,
+            paginatorListener: packages!,
             rowBuilder: (p) => PackageListRow(
               key: ValueKey(p.id),
               package: p,