This plugin is also available as a template in ApparenceKit.

🚀  Overview

Bart is very simple solution to implement tabulation system layout with Navigator into your application.

• 📱 Material & Cupertino themes available.
• 🤝 Automatic theme switching between material & cupertino.
• 🛣 Inner routing inside tab.
• 🥷 Parent routing (over tabbar content).
• 😌 Very easy to implement.
• 🪄 Show AppBar on demand (automatically animated).
• 🚀 Create your own bottom bar design if you need it.
• 👻 Hide/Show bottom bar when you need
• 🗃 Cache route page if you need to restore state.

🧐  Live example

📖  Installation

Install the package

flutter pub add bart

Import the package

import 'package:bart/bart.dart';

🚀  Get started

• Define in your page the routing tab

List<BartMenuRoute> subRoutes() {
  return [
    BartMenuRoute.bottomBar(
      label: "Home",
      icon: Icons.home,
      path: '/home',
      pageBuilder: (context) => PageFake(
        key: PageStorageKey<String>("home"), // this is required to enable state caching
        Colors.red,
      ),
    ),
    BartMenuRoute.bottomBar(
      label: "Library",
      icon: Icons.video_library_rounded,
      path: '/library',
      pageBuilder: (context) => PageFake(Colors.blueGrey),
    ),
    BartMenuRoute.bottomBar(
      label: "Profile",
      icon: Icons.person,
      path: '/profile',
      pageBuilder: (context) => PageFake(Colors.yellow),
    ),
    BartMenuRoute.innerRoute( // add an inner route, no item will be added in bottom bar
      path: '/subpage',
      pageBuilder: (context) =>
          PageFake(Colors.greenAccent, child: Text("Sub Route page")),
    ),
  ];
}

BartMenuRoute.bottomBar(...)

BartMenuRoute.innerRoute(...)

• Create your main page which include the Bart tabbar Scaffold

class MainPageMenu extends StatelessWidget {
  const MainPageMenu({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return BartScaffold(
      routesBuilder: subRoutes, // add a reference to the subRoutes list you created before
      bottomBar: BartBottomBar.adaptive(), // add the bottom bar (see below for other options)
    );
  }
}

🏞  Bottom bar themes

Bart include 4 ways to display a bottom bar:

BartBottomBar.cupertino() // iOS look.
BartBottomBar.material3() // Android look.
BartBottomBar.adaptive() // automatically select between cupertino & material depending on the device.
BartBottomBar.custom() // your own design

To custom the bottom bar, simply extends BartBottomBarCustom and create your own bottom bar like SimpleBottomBar(in example project).

🤖  Material 3 bottom bar

If you want to custom your material 3 bottom bar, you can use the BottomNavigationBarThemeData class in your theme.

ThemeData(
  navigationBarTheme: NavigationBarThemeData(
    backgroundColor: Colors.orange.shade100,
    indicatorColor: Colors.orange.shade700,
  ),
)

🗃  Bottom icon notfication badge

You can add a notification badge on your bottom bar icon.

To do that, you need to use the BartMenuRoute.bottomBarBuilder method instead of BartMenuRoute.bottomBar in your route definitions:

BartMenuRoute.bottomBarBuilder(
    label: "Library",
    builder: (context) => BottomBarIcon.builder(
        icon: const Icon(Icons.video_library_outlined),
        notificationBuilder: (context) => Container(
            decoration: const BoxDecoration(
                color: Colors.red,
                shape: BoxShape.circle,
            ),
            padding: const EdgeInsets.all(4),
                child: const Text(
                "1",
                style: TextStyle(color: Colors.white, fontSize: 10),
                ),
            ),
        ),
    path: '/library',
    pageBuilder: (parentContext, tabContext, settings) => const FakeListPage(
    key: PageStorageKey<String>("library"),
    ),
    transitionDuration: bottomBarTransitionDuration,
    transitionsBuilder: bottomBarTransition,
),

🌏  Web sidebar menu

You can choose to use the material sidebar NavigationRail

Like this

return BartScaffold(
    routesBuilder: subRoutes,
    showBottomBarOnStart: true,
    bottomBar: BartBottomBar.material3(),
    sideBarOptions: RailSideBarOptions(
        extended: true,
        gravity: Gravity.left,
    ),
)

(To change the theme you can do it like all regular material theme in the ThemeData).

Or you can make your own

return BartScaffold(
    routesBuilder: subRoutes,
    showBottomBarOnStart: true,
    bottomBar: BartBottomBar.material3(),
    sideBarOptions: CustomSideBarOptions(
        gravity: Gravity.left,
        sideBarBuilder: ((onTapItem, currentItem) => ...)
    ),
)

🗃  State caching

How it works 🤔 ?

Imagine you got a page with a counter. You increment this counter and change tab. You want this tab to come back with the incremented counter?.

Bart include a caching system to implement this feature.

By default state caching is enabled. But you can override it:

BartMenuRoute.bottomBar(cache: false)

How to use it 🤓 ?

Your tab pages you want to be cached must use a PageStorageKey property:

BartMenuRoute.bottomBar(
  label: "Library",
  icon: Icons.video_library_rounded,
  path: '/library',
  pageBuilder: (context, settings) => PageFake(
    key: PageStorageKey<String>("library"), // add this property
    child: Text('Cached page !'),
  ),

🗃  Show/Hide animated AppBar

You can show an animated AppBar or hide it whenever you want inside all your Bart sub pages.

AppBar will automatically shows or hide with a smooth animation

Simply add the AppBarNotifier mixin like this:

class MyPage extends StatelessWidget with AppBarNotifier {
  const MyPage({ Key? key }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    // use the update app bar method to dynamically change app bar
    updateAppBar(context, AppBar(title: Text("test")));
    // now call you can call show method that will start animation
    showAppBar(context);
    return Container();
  }
}

To hide app bar, just execute this code inside your widget with AppBarNotifier

hideAppBar(context);

You can also use Actions to performs AppBar related actions

Actions.invoke(context, AppBarBuildIntent(AppBar(title: Text("title text"))));
Actions.invoke(context,AppBarAnimationIntent.show());
Actions.invoke(context,AppBarAnimationIntent.hide());

🫥  Show/hide bottom bar

Sometimes you wants to hide the bottom menu bar. As this is possible for the appbar you can use a mixin for that. It just require to be called from a sub context of the BartScaffold.

Actions.invoke(context, BottomBarIntent.show());
Actions.invoke(context, BottomBarIntent.hide());

Or use the mixin

class MyPage extends StatelessWidget with BartNotifier {
  const MyPage({ Key? key }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    // directly show the bottom bar
    showBottomBar(context);
    // directly hide the bottom bar
    hideBottomBar(context);
    return Container();
  }
}

💫  Transitions between items

You can use the official animation plugin to create better transition or create your owns.

Example:

BartMenuRoute.bottomBar(
  label: "Library",
  icon: Icons.video_library_rounded,
  path: '/library',
  pageBuilder: (context, settings) => PageFake(Colors.blueGrey),
  transitionDuration: Duration(milliseconds: 500),
  transitionsBuilder: (context, anim1, anim2, widget) => FadeThroughTransition(
    animation: anim1,
    secondaryAnimation: anim2,
    child: widget,
  ),
),

📣  Sponsor

Initiated and sponsored by Apparence.io.

👥  Contribution

Contributions are welcome. Contribute by creating a PR or create an issue 🎉.