Can you explain the concept and main features of Navigator 2.0?

Navigator 2.0 in Flutter is a new navigation system that provides more control over routing and navigation state compared to the traditional Navigator 1.0.

Main features of Navigator 2.0:

• Declarative approach: instead of calling push/pop methods, you describe the current navigation state through a list of pages.
• Support for URL and deep linking: allows synchronization of navigation state with the URL, which is important for web applications.
• Flexibility: enables implementation of complex navigation scenarios, such as nested navigation stacks.
• RouterDelegate and RouteInformationParser: key classes for managing navigation and parsing URLs.

Example of simplified usage of Navigator 2.0:

class MyRouterDelegate extends RouterDelegate<MyRoutePath> with ChangeNotifier, PopNavigatorRouterDelegateMixin<MyRoutePath> {
  final GlobalKey<NavigatorState> navigatorKey;

  MyRouterDelegate() : navigatorKey = GlobalKey<NavigatorState>();

  MyRoutePath _currentPath;

  @override
  Widget build(BuildContext context) {
    return Navigator(
      key: navigatorKey,
      pages: [
        MaterialPage(child: HomeScreen()),
        if (_currentPath.isDetailsPage) MaterialPage(child: DetailsScreen()),
      ],
      onPopPage: (route, result) {
        if (!route.didPop(result)) return false;
        _currentPath = MyRoutePath.home();
        notifyListeners();
        return true;
      },
    );
  }

  @override
  Future<void> setNewRoutePath(MyRoutePath path) async {
    _currentPath = path;
  }
}

Thus, Navigator 2.0 allows for better control of navigation and integration with external sources, such as the browser URL.