material_navigation 0.0.1

Material 3 Expressive navigation.

material_navigation

Material 3 Expressive navigation for Flutter — the flexible navigation bar, the collapsing/expanding navigation rail.

Getting started

flutter pub add material_navigation

These widgets share names with Flutter's Material library, so hide the SDK's versions at the import:

import 'package:flutter/material.dart' hide NavigationBar, NavigationRail, NavigationDestination;
import 'package:material_navigation/material_navigation.dart';

Everything is exported from that single barrel.

Examples

A navigation rail

The rail owns its expand state; a menu button in the leading slot toggles it through NavigationRail.of(context). Use a Builder so the button's context sits below the rail.

NavigationRail(
  selectedIndex: _index,
  onDestinationSelected: (i) => setState(() => _index = i),
  leading: Builder(
    builder: (context) => IconButton(
      icon: const Icon(Icons.menu),
      onPressed: NavigationRail.of(context).toggle, // .toggleModal() for an overlay
    ),
  ),
  destinations: const [
    NavigationDestination(icon: Icon(Icons.inbox_outlined), selectedIcon: Icon(Icons.inbox), label: 'Inbox'),
    NavigationDestination(icon: Icon(Icons.send_outlined), selectedIcon: Icon(Icons.send), label: 'Sent'),
    NavigationDestination(icon: Icon(Icons.archive_outlined), selectedIcon: Icon(Icons.archive), label: 'Archive'),
  ],
)

A rail with secondary destinations

expandedBody is revealed only while the rail is expanded — per Material 3, the place for the secondary destinations a collapsed rail can't show.

NavigationRail(
  selectedIndex: _index,
  onDestinationSelected: (i) => setState(() => _index = i),
  leading: Builder(
    builder: (context) => IconButton(
      icon: const Icon(Icons.menu),
      onPressed: NavigationRail.of(context).toggle,
    ),
  ),
  destinations: const [
    NavigationDestination(icon: Icon(Icons.inbox_outlined), selectedIcon: Icon(Icons.inbox), label: 'Inbox'),
    NavigationDestination(icon: Icon(Icons.send_outlined), selectedIcon: Icon(Icons.send), label: 'Sent'),
  ],
  expandedBody: Column(
    children: const [
      ListTile(leading: Icon(Icons.label_outline), title: Text('Promotions')),
      ListTile(leading: Icon(Icons.label_outline), title: Text('Social')),
      ListTile(leading: Icon(Icons.label_outline), title: Text('Updates')),
    ],
  ),
)

A flexible navigation bar

Same shape as Flutter's own NavigationBar — the familiar selectedIndex / onDestinationSelected / destinations triad and NavigationDestination(icon:, selectedIcon:, label:).

Set layoutDirection: Axis.horizontal and the items lay their icon beside the label and center as a group with outer margins. Toggling layoutDirection animates the morph under motion.

NavigationBar(
  layoutDirection: Axis.horizontal, // or Axis.vertical 
  selectedIndex: _index,
  onDestinationSelected: (i) => setState(() => _index = i),
  destinations: const [
    NavigationDestination(icon: Icon(Icons.home_outlined), selectedIcon: Icon(Icons.home), label: 'Home'),
    NavigationDestination(icon: Icon(Icons.search), label: 'Search'),
    NavigationDestination(icon: Icon(Icons.person_outline), selectedIcon: Icon(Icons.person), label: 'Profile'),
  ],
)

Motion

Both the bar and the rail take a motion. Material 3 Expressive spring physics drive the transition unless you pass NavigationMotion.standard() for a fixed duration and curve.

NavigationRail( // spring (Expressive)
  motion: const NavigationMotion.expressive(),
  // ...
);

NavigationRail( // a softer, custom spring
  motion: const NavigationMotion.expressive(
    spring: SpringDescription(mass: 1, stiffness: 300, damping: 30),
  ),
  // ...
);

NavigationBar( // a fixed duration eased by a curve
  motion: const NavigationMotion.standard(
    duration: Duration(milliseconds: 300),
    curve: Curves.easeInOutCubicEmphasized,
  ),
  // ...
);

Styling

Each component resolves a token bundle from the ambient Theme. Build one explicitly from a ColorScheme and TextTheme, then adjust individual tokens with copyWith. NavigationBarStyle.baseline(...) and NavigationRailStyle.baseline(...) build the pre-Expressive Material 3 variants.

final theme = Theme.of(context);

NavigationRail( // the expressive rail, widened to 320dp
  style: NavigationRailStyle.expressive(theme.colorScheme, theme.textTheme)
      .copyWith(expandedWidth: 320),
  // ...
);

NavigationBar( // the flexible (64dp) bar with a custom indicator color
  style: NavigationBarStyle.flexible(theme.colorScheme, theme.textTheme)
      .copyWith(indicatorColor: Colors.amber),
  // ...
);

Components

Type	What it is
NavigationBar	A bottom navigation bar of three to five destinations; Material 3 Expressive flexible 64dp or baseline 80dp.
NavigationBarStyle	The token bundle driving a bar; .flexible (Expressive) / .baseline factories plus copyWith.
NavigationRail	A rail that collapses and expands, in place or as a modal overlay, with leading, floatingActionButton, trailing, and expandedBody slots.
NavigationRailHandle	The handle from NavigationRail.of(context): open, openModal, close, toggle, toggleModal, isOpen, isModal, expandAnimation.
NavigationRailStyle	The token bundle driving a rail; .expressive / .baseline factories plus copyWith.
NavigationDestination	A destination shared by the bar and the rail that morphs between the vertical and horizontal layouts.
NavigationDestinationStyle	The resolved per-item styling — colors, label styles, and state layer.
NavigationLabelBehavior	When the below-label is shown: all, selected, or none.
NavigationIndicatorSize	How the expanded active indicator is sized: fill (full width) or label (hugs content).
NavigationMotion	The shared motion: .expressive() (spring physics) or .standard() (duration + curve).