nav2_router_delegate_02

router_delegate_02.dart

class MyAppRouterDelegate extends RouterDelegate with ChangeNotifier, PopNavigatorRouterDelegateMixin {

  final GlobalKey<NavigatorState> _navigatorKey;

  bool _loggedIn;
  bool get loggedIn => _loggedIn;
  set loggedIn(value) {
    _loggedIn = value;
    notifyListeners();
  }

  String _selectedColorCode;
  String get selectedColorCode => _selectedColorCode;
  set selectedColorCode(String value) {
    _selectedColorCode = value;
    notifyListeners();
  }

  ShapeBorderType _selectedShapeBorderType;
  ShapeBorderType get selectedShapeBorderType => _selectedShapeBorderType;
  set selectedShapeBorderType(ShapeBorderType value) {
    _selectedShapeBorderType = value;
    notifyListeners();
  }

  final AuthRepository authRepository;

  @override
  GlobalKey<NavigatorState> get navigatorKey => _navigatorKey;

  MyAppRouterDelegate(this.authRepository) : _navigatorKey = GlobalKey<NavigatorState>() {
    _init();
  }

  _init() async {
    loggedIn = await authRepository.isUserLoggedIn();
  }

  @override
  Widget build(BuildContext context) {
    List<Page> stack;
    if (loggedIn == null) {
      stack = _splashStack;
    } else if (loggedIn) {
      stack = _loggedInStack;
    } else {
      stack = _loggedOutStack;
    }
    return Navigator(
      key: navigatorKey,
      pages: stack,
      onPopPage: (route, result) {
        if (!route.didPop(result)) return false;
        if (selectedShapeBorderType == null) selectedColorCode = null;
        selectedShapeBorderType = null;
        return true;
      },
    );
  }

  List<Page> get _splashStack => [SplashPage(process: 'Splash Screen:\n\nChecking auth state')];

  List<Page> get _loggedOutStack => [
        LoginPage(onLogin: () {
          loggedIn = true;
        })
      ];

  List<Page> get _loggedInStack {
    final onLogout = () {
      loggedIn = false;
      _clear();
    };
    return [
      HomePage(
        onColorTap: (String colorCode) {
          selectedColorCode = colorCode;
        },
        onLogout: onLogout,
      ),
      if (selectedColorCode != null)
        ColorPage(
          selectedColorCode: selectedColorCode,
          onShapeTap: (ShapeBorderType shapeBorderType) {
            this.selectedShapeBorderType = shapeBorderType;
          },
          onLogout: onLogout,
        ),
      if (selectedShapeBorderType != null)
        ShapePage(
          colorCode: selectedColorCode,
          shapeBorderType: selectedShapeBorderType,
          onLogout: onLogout,
        )
    ];
  }

  _clear() {
    selectedColorCode = null;
    selectedShapeBorderType = null;
  }

  @override
  Future<void> setNewRoutePath(configuration) async { /* Do Nothing */ }
}

If you are using Provider, why do you have:

  bool _loggedIn;
  bool get loggedIn => _loggedIn;
  set loggedIn(value) {
    _loggedIn = value;
    notifyListeners();
  }

  String _selectedColorCode;
  String get selectedColorCode => _selectedColorCode;
  set selectedColorCode(String value) {
    _selectedColorCode = value;
    notifyListeners();
  }

  ShapeBorderType _selectedShapeBorderType;
  ShapeBorderType get selectedShapeBorderType => _selectedShapeBorderType;
  set selectedShapeBorderType(ShapeBorderType value) {
    _selectedShapeBorderType = value;
    notifyListeners();
  }

inside MyAppRouterDelegate instead of using Provider for creating separate AppState

class AppState extends ChangeNotifier {
  bool _loggedIn;
  bool get loggedIn => _loggedIn;
  set loggedIn(value) {
    _loggedIn = value;
    notifyListeners();
  }

  String _selectedColorCode;
  String get selectedColorCode => _selectedColorCode;
  set selectedColorCode(String value) {
    _selectedColorCode = value;
    notifyListeners();
  }

  ShapeBorderType _selectedShapeBorderType;
  ShapeBorderType get selectedShapeBorderType => _selectedShapeBorderType;
  set selectedShapeBorderType(ShapeBorderType value) {
    _selectedShapeBorderType = value;
    notifyListeners();
  }
}

and injecting this AppState using:

MultiProvider(
      providers: [
        ChangeNotifierProvider<AuthViewModel>(create: (_) => AuthViewModel(authRepository)),
        ChangeNotifierProvider<AppState>(create: (_) => AppState()),
      ],
      child: Builder(
        builder: (context) => MaterialApp(home: Router(routerDelegate: delegate)),)
      ),
    )

so in MyAppRouterDelegate you could simply do:

  @override
  Widget build(final BuildContext context) {
    final AppState appState = context.watch<AppState>();
    List<Page> stack;
    if (appState.loggedIn == null) {
      stack = _splashStack;
    } else if (appState.loggedIn) {
      stack = _loggedInStack;
    } else {
      stack = _loggedOutStack;
    }
    return Navigator(
      key: navigatorKey,
      pages: stack,
      onPopPage: (route, result) {
        if (!route.didPop(result)) return false;
        if (selectedShapeBorderType == null) selectedColorCode = null;
        selectedShapeBorderType = null;
        return true;
      },
    );
  }

?
(of course this requires you to pass AppState to the HomePage, ColorPage, and ShapePage accordingly)