Flutter navigationBar with Riverpod

Question

I try to manage my states but I can't really do it. I would like to learn how to create a navigation bar at the bottom of the manage page with the riverpod package.

I manage to manage the page on which we click but I do not see how to then return the correct pager according to the selected button

Main.dart :

import 'package:flutter/material.dart';
import 'package:hooks_riverpod/hooks_riverpod.dart';
import 'package:app/ui/screens/my_app/my_app_screen.dart';

void main() {
  runApp(
    const ProviderScope(child: MyApp()),
  );
}

NavigationBarScreen.dart:

import 'package:flutter/material.dart';
import 'package:flutter_hooks/flutter_hooks.dart';
import 'package:hooks_riverpod/hooks_riverpod.dart';

final provider = StateNotifierProvider((ref) => NavigationNotifier());

class NavigationBarScreen extends HookWidget
{
  @override
  Widget build(BuildContext context) {

    return SafeArea(
      child: Scaffold(
        body : Container(
              margin: EdgeInsets.only(left : 8, right : 8, bottom: 8),
              decoration: BoxDecoration(
                borderRadius: BorderRadius.only(
                    topRight: Radius.circular(20), topLeft: Radius.circular(20)),
                boxShadow: [
                  BoxShadow(color: AppColors.colorShadowLight, spreadRadius: 0, blurRadius: 10),
                ],
              ),
              child: ClipRRect(
                borderRadius: BorderRadius.circular(50.0),
                child: BottomNavigationBar(
                  type: BottomNavigationBarType.fixed,
                  backgroundColor: AppColors.colorBgDark,
                  fixedColor: AppColors.colorContrastOrange,
                  unselectedItemColor: AppColors.colorFontLight2,
                  currentIndex: 0,
                  showSelectedLabels: false,
                  showUnselectedLabels: false,
                  onTap: context.read(provider).selectPage,
                  items: [
                    BottomNavigationBarItem(
                      icon: Icon(Icons.home),
                      title: Text('Home'),
                    ),
                    BottomNavigationBarItem(
                      icon: Icon(Icons.settings),
                      title: Text('Settings'),
                    ),
                  ],
                ),
              ),
            ),
      ),
    );
  }
}

NavigationNotifier.dart:

import 'package:hooks_riverpod/hooks_riverpod.dart';

enum NavigationBarEvent { HOME, PROFIL}

class NavigationNotifier extends StateNotifier<PageModel> {
  NavigationNotifier() : super(defaultPage);

  static const defaultPage = PageModel(NavigationBarEvent.HOME);

  void selectPage(int i){
    switch (i) {
      case 0:
        state = PageModel(NavigationBarEvent.HOME);
        break;
      case 1:
        state = PageModel(NavigationBarEvent.PROFIL);
        break;
    }
  }
}

class PageModel {
  const PageModel(this.page);
  final NavigationBarEvent page;
}

Answer 1

Updated Jan 27, 2022. https://pub.dev/packages/flutter_riverpod/versions/1.0.3

This is another approach that worked for me, if you are looking to control "pageview + bottom navigation bar" on drag as well:

class Index extends StateNotifier<int> {
  Index() : super(0);
  set value(int index) => state = index;
}

final indexProvider = StateNotifierProvider((ref) => Index());

class Home extends ConsumerWidget {
  static const route = '/home';
  const Home({Key? key}) : super(key: key);

  final List<Widget> fragments = const [
    Text('Page 1'),
    Text('Page 2'),
    Text('Page 3')
  ];

  final List<BottomNavigationBarItem> navItems = const [
    BottomNavigationBarItem(icon: Icon(Icons.home), label: 'Home'),
    BottomNavigationBarItem(icon: Icon(Icons.camera), label: 'Camera'),
    BottomNavigationBarItem(icon: Icon(Icons.edit), label: 'Edit'),
  ];

  final Text title = const Text('My App');

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final PageController controller = PageController();
    final int menuIndex = ref.watch(indexProvider) as int;
    return Scaffold(
      appBar: AppBar(title: title, actions: [
        IconButton(onPressed: () {}, icon: const Icon(Icons.list))
      ]),
      body: PageView(
          controller: controller,
          children: fragments,
          onPageChanged: (i) => ref.read(indexProvider.notifier).value = i),
      bottomNavigationBar: BottomNavigationBar(
          items: navItems,
          currentIndex: menuIndex,
          onTap: (i) {
            ref.read(indexProvider.notifier).value = i;
            controller.animateToPage(i,
                duration: const Duration(seconds: 1), curve: Curves.easeInOut);
          }),
    );
  }
}