A frosted-glass bottom navigation bar, with an animated selection indicator, per-item active colours and two layouts.

GlassyNavbarType.centered a floating pill	GlassyNavbarType.bottom docked to the edge	with a centerDocked action button

Features

• Frosted glass — blurs whatever scrolls behind it, with a configurable sigma
• Animated background indicator that slides to the selected item
• Animated marker above the selected icon
• Per-item active colour, tinting both the indicator and the marker
• Separate icon for the selected state
• Two layouts: docked to the bottom edge, or a floating pill
• Labels on the selected item, the unselected items, both or neither
• Styleable labels, with a separate style for the selected one
• Self-tracking or fully controlled by the parent, for a PageController or a router
• Configurable blur, tint, border, corner radius, margin, padding, marker size and animation duration

Usage

The bar blurs what is painted behind it, so put it in a Scaffold with extendBody: true:

Scaffold(
  extendBody: true,
  body: const MyPage(),
  bottomNavigationBar: GlassyBottomNav(
    onChange: (index) => setState(() => _index = index),
    items: [
      GlassyBottomNavItem(
        icon: const Icon(Icons.home_outlined),
        activeIcon: const Icon(Icons.home),
        label: 'Home',
        activeColor: Colors.green,
      ),
      GlassyBottomNavItem(
        icon: const Icon(Icons.favorite_border),
        activeIcon: const Icon(Icons.favorite),
        label: 'Favorite',
        activeColor: Colors.red,
      ),
    ],
  ),
)

Without activeColor an item falls back to the theme's colorScheme.secondary.

Layouts

navbarType picks the shape. GlassyNavbarType.centered (the default) floats the bar as a pill, inset from the bottom and the sides:

GlassyBottomNav(
  navbarType: GlassyNavbarType.centered,
  items: items,
)

GlassyNavbarType.bottom docks it to the bottom edge, spanning the full width with only the top corners rounded:

GlassyBottomNav(
  navbarType: GlassyNavbarType.bottom,
  items: items,
)

Either can be overridden with margin and borderRadius.

Controlled selection

By default the bar tracks the selection itself, starting at initialIndex. Pass currentIndex when something else owns the current page — a PageController, a router, or your own state. Taps then only report through onChange, and the bar moves when you pass a new currentIndex:

GlassyBottomNav(
  currentIndex: _index,
  onChange: (index) {
    setState(() => _index = index);
    _pageController.animateToPage(
      index,
      duration: const Duration(milliseconds: 300),
      curve: Curves.easeOut,
    );
  },
  items: items,
)

Styling the glass

GlassyBottomNav(
  backgroundBlur: 20,
  backgroundColor: Colors.black,
  borderThickness: 0.5,
  borderColor: Colors.white.withValues(alpha: 0.15),
  showUnselectedLabel: false,
  labelStyle: const TextStyle(fontSize: 11),
  selectedLabelStyle: const TextStyle(fontWeight: FontWeight.bold),
  markerSize: const Size(24, 3),
  duration: const Duration(milliseconds: 250),
  items: items,
)

GlassyBottomNav

Parameter	Default	Description
items	required	The destinations, laid out with equal widths
initialIndex	0	The index selected on first build
currentIndex	null	Set it to drive the selection from outside
onChange	null	Called with the new index when a different item is tapped
navbarType	centered	Floating pill, or docked to the bottom edge
showBackgroundIndicator	true	Tinted panel behind the selected item
backgroundBlur	10	Blur sigma applied to the backdrop
backgroundColor	null	Tints the glass, at 10% opacity
borderRadius	type default	25 for bottom, 50 for centered
borderThickness	null	No border is drawn when null
borderColor	translucent white	Ignored unless borderThickness is set
margin	type default	Space around the bar
padding	EdgeInsets.zero	Space between the bar's edges and its items
showSelectedLabel	true	Label under the selected icon
showUnselectedLabel	true	Labels under the other icons
labelStyle	white 12px	Merged over the default label style
selectedLabelStyle	null	Merged over labelStyle when selected
markerSize	Size(20, 3)	Marker above the selected icon
duration	150ms	Indicator and marker animation

GlassyBottomNavItem

Parameter	Default	Description
icon	required	Shown while the item is not selected
activeIcon	icon	Shown while the item is selected
label	required	Text under the icon, and the item's tooltip
activeColor	colorScheme.secondary	Tints the marker and the indicator

Example

See example/ for a four-destination app that drives the bar from a PageController. Its header has two switches: one flips between the layouts, the other docks a FloatingActionButtonLocation.centerDocked button over the bar, which works with either layout.