change to resolve reviews ;)

lib/src/navbar_decoration.dart

@@ -3,7 +3,10 @@ import 'package:navbar_router/navbar_router.dart';
 
 class NavbarItem {
   const NavbarItem(this.iconData, this.text,
-      {this.backgroundColor, this.child, this.selectedIcon, this.badge});
+      {this.backgroundColor,
+      this.child,
+      this.selectedIcon,
+      this.badge = const NavbarBadge()});
 
   /// IconData for the navbar item
   final IconData iconData;
@@ -23,7 +26,7 @@ class NavbarItem {
   final Widget? selectedIcon;
 
   /// Your initial badge configuration for this item, this is totally optional
-  final NavbarBadge? badge;
+  final NavbarBadge badge;
 
   @override
   bool operator ==(Object other) =>

lib/src/navbar_notifier.dart

@@ -44,25 +44,27 @@ class NavbarNotifier extends ChangeNotifier {
   static void updateBadge(int index, NavbarBadge badge) {
     if (index < 0 || index >= length) return;
     _badges[index] = badge;
-    // TODO: wonder if this will cause performance issue
-    NavbarNotifier.index = index;
+
+    // We don't navigate to that item when we update its badge. So cannot use this.
+    // NavbarNotifier.index = index;
+
     _singleton.notify();
   }
 
   /// Use to set the visibility of a badge using its [index].
   static void makeBadgeVisible(int index, bool visible) {
     if (index < 0 || index >= length) return;
     _badges[index] = _badges[index].copyWith(showBadge: visible);
-    _notifyIndexChangeListeners(index);
+
     _singleton.notify();
   }
 
-  /// Conveniently setup the badges if user choose to show them. Also the only place that init the badges.
-  ///
-  /// Will throw AssertionError if length of keys and given badgeList are not the same
-  static void setKeys(List<GlobalKey<NavigatorState>> value,
-      {List<NavbarBadge>? badgeList}) {
+  static void setKeys(List<GlobalKey<NavigatorState>> value) {
     _keys = value;
+  }
+
+  /// The only place that init the badges.
+  static void setBadges(List<NavbarBadge>? badgeList) {
     if (badgeList != null) {
       _badges = badgeList;
     }

lib/src/navbar_router.dart

@@ -204,11 +204,14 @@ class _NavbarRouterState extends State<NavbarRouter>
       final navbaritem = widget.destinations[i].navbarItem;
       keys.add(GlobalKey<NavigatorState>());
       items.add(navbaritem);
-      badges.add(navbaritem.badge ?? const NavbarBadge());
+      badges.add(navbaritem.badge);
     }
+    NavbarNotifier.setKeys(keys);
+
     // set badge list here
-    NavbarNotifier.setKeys(keys, badgeList: badges);
+    NavbarNotifier.setBadges(badges);
     NavbarNotifier.hideBadgeOnPageChanged = widget.hideBadgeOnPageChanged;
+
     if (!isUpdate) {
       initAnimation();
       NavbarNotifier.index = widget.initialIndex;