packages/go_router_builder/example/lib/shell_route_with_observers_example.dart

// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// ignore_for_file: public_member_api_docs, unreachable_from_main

import 'package:flutter/material.dart';
import 'package:go_router/go_router.dart';

part 'shell_route_with_observers_example.g.dart';

void main() => runApp(App());

class App extends StatelessWidget {
  App({super.key});

  @override
  Widget build(BuildContext context) => MaterialApp.router(
        routerConfig: _router,
      );

  final GoRouter _router = GoRouter(
    routes: $appRoutes,
    initialLocation: '/home',
  );
}

@TypedShellRoute<MyShellRouteData>(
  routes: <TypedRoute<RouteData>>[
    TypedGoRoute<HomeRouteData>(path: '/home'),
    TypedGoRoute<UsersRouteData>(
      path: '/users',
      routes: <TypedGoRoute<UserRouteData>>[
        TypedGoRoute<UserRouteData>(path: ':id'),
      ],
    ),
  ],
)
class MyShellRouteData extends ShellRouteData {
  const MyShellRouteData();

  static final List<NavigatorObserver> $observers = <NavigatorObserver>[
    MyNavigatorObserver()
  ];

  @override
  Widget builder(BuildContext context, GoRouterState state, Widget navigator) {
    return MyShellRouteScreen(child: navigator);
  }
}

class MyNavigatorObserver extends NavigatorObserver {
  @override
  void didPush(Route<dynamic> route, Route<dynamic>? previousRoute) {}
}

class MyShellRouteScreen extends StatelessWidget {
  const MyShellRouteScreen({required this.child, super.key});

  final Widget child;

  int getCurrentIndex(BuildContext context) {
    final String location = GoRouterState.of(context).uri.toString();
    if (location.startsWith('/users')) {
      return 1;
    }
    return 0;
  }

  @override
  Widget build(BuildContext context) {
    final int selectedIndex = getCurrentIndex(context);

    return Scaffold(
      body: Row(
        children: <Widget>[
          NavigationRail(
            destinations: const <NavigationRailDestination>[
              NavigationRailDestination(
                icon: Icon(Icons.home),
                label: Text('Home'),
              ),
              NavigationRailDestination(
                icon: Icon(Icons.group),
                label: Text('Users'),
              ),
            ],
            selectedIndex: selectedIndex,
            onDestinationSelected: (int index) {
              switch (index) {
                case 0:
                  const HomeRouteData().go(context);
                case 1:
                  const UsersRouteData().go(context);
              }
            },
          ),
          const VerticalDivider(thickness: 1, width: 1),
          Expanded(child: child),
        ],
      ),
    );
  }
}

class HomeRouteData extends GoRouteData {
  const HomeRouteData();

  @override
  Widget build(BuildContext context, GoRouterState state) {
    return const Center(child: Text('The home page'));
  }
}

class UsersRouteData extends GoRouteData {
  const UsersRouteData();

  @override
  Widget build(BuildContext context, GoRouterState state) {
    return ListView(
      children: <Widget>[
        for (int userID = 1; userID <= 3; userID++)
          ListTile(
            title: Text('User $userID'),
            onTap: () => UserRouteData(id: userID).go(context),
          ),
      ],
    );
  }
}

class DialogPage extends Page<void> {
  /// A page to display a dialog.
  const DialogPage({required this.child, super.key});

  /// The widget to be displayed which is usually a [Dialog] widget.
  final Widget child;

  @override
  Route<void> createRoute(BuildContext context) {
    return DialogRoute<void>(
      context: context,
      settings: this,
      builder: (BuildContext context) => child,
    );
  }
}

class UserRouteData extends GoRouteData {
  const UserRouteData({required this.id});

  // Without this static key, the dialog will not cover the navigation rail.
  final int id;

  @override
  Page<void> buildPage(BuildContext context, GoRouterState state) {
    return DialogPage(
      key: state.pageKey,
      child: Center(
        child: SizedBox(
          width: 300,
          height: 300,
          child: Card(child: Center(child: Text('User $id'))),
        ),
      ),
    );
  }
}