Update NavigationRailM3E implementation; update FAB and navigation sections to adapt to changes.

packages/navigation_rail_m3e/README.md

@@ -1,84 +1,51 @@
 # navigation_rail_m3e
 
-Material 3 **Expressive** Navigation Rail for Flutter with badges, pill/stripe indicators, and token-driven styling.
+Material 3 **Expressive** Navigation Rail for Flutter — featuring **collapsed** & **expanded** variants,
+**modal** and **standard** presentation, **sections**, **badges**, **menu** and **FAB** slots, and smooth
+**expand/collapse transitions**. Built to match the M3 Expressive spec and integrate with the `m3e_design`
+token package.
 
-- `NavigationRailM3E` — wrapper around Flutter's `NavigationRail` with M3E tokens
-- `RailDestinationM3E` — destination data (icon, selectedIcon, label, badge)
-- `RailBadgeM3E` — small badge/dot utility for icons
+<img src="https://raw.githubusercontent.com/EmilyMonestone/material_3_expressive/main/.github/images/nav_rail_m3e_cover.png" width="980"/>
 
-All styling is driven by the `m3e_design` ThemeExtension (**M3ETheme**).
+## Highlights
 
-## Monorepo Layout
+- Collapsed (96 dp) and Expanded (220–360 dp) rails with animated transition
+- Expanded **modal** presentation with scrim
+- Optional menu and FAB/Extended FAB slots
+- Item badges (large numeric & small dot)
+- Sections with headers; full-width hit targets
+- Token-driven colors, typography & shapes via `m3e_design` (with safe fallbacks)
 
-```
-packages/
-  m3e_design/
-  navigation_rail_m3e/
-```
-
-`pubspec.yaml` references `../m3e_design`.
-
-## Usage
+## Quick start
 
 ```dart
-import 'package:navigation_rail_m3e/navigation_rail_m3e.dart';
-
-final items = [
-  const RailDestinationM3E(
-    icon: Icon(Icons.inbox_outlined),
-    selectedIcon: Icon(Icons.inbox),
-    label: 'Inbox',
-  ),
-  const RailDestinationM3E(
-    icon: Icon(Icons.chat_bubble_outline),
-    label: 'Chat',
-    badgeCount: 5,
-  ),
-  const RailDestinationM3E(
-    icon: Icon(Icons.settings_outlined),
-    label: 'Settings',
-    badgeDot: true,
-  ),
-];
-
 NavigationRailM3E(
-  destinations: items,
+  type: NavigationRailM3EType.expanded,
+  modality: NavigationRailM3EModality.standard,
   selectedIndex: 0,
-  onDestinationSelected: (i) {},
-  labelBehavior: RailLabelBehavior.onlySelected, // none | onlySelected | alwaysShow
-  indicatorStyle: RailIndicatorStyle.pill,       // pill | stripe | none
-  size: RailSize.regular,                        // compact | regular
-  density: RailDensity.regular,                  // regular | compact
-  shapeFamily: RailShapeFamily.round,            // round | square
-  extended: false,                               // true to show labels permanently (wide rail)
-  groupAlignment: -1.0,                          // -1 top .. 1 bottom
-  leading: const Padding(
-    padding: EdgeInsets.all(8.0),
-    child: FlutterLogo(size: 24),
-  ),
+  onDestinationSelected: (i) => setState(() => _index = i),
+  onTypeChanged: (t) => setState(() => type = t),
+  fab: NavigationRailM3EFabSlot(icon: const Icon(Icons.add), label: 'New', onPressed: () {}),
+  sections: [
+    NavigationRailM3ESection(
+      header: const Text('Main'),
+      destinations: [
+        NavigationRailM3EDestination(
+          icon: const Icon(Icons.edit_outlined),
+          selectedIcon: const Icon(Icons.edit),
+          label: 'Edit',
+          largeBadgeCount: 0,
+        ),
+        NavigationRailM3EDestination(
+          icon: const Icon(Icons.star_outline),
+          selectedIcon: const Icon(Icons.star),
+          label: 'Starred',
+          smallBadge: true,
+        ),
+      ],
+    ),
+  ],
 );
 ```
 
-## Tokens mapping
-
-- **Container**: `surfaceContainerHigh`
-- **Indicator**: `secondaryContainer` (color). `pill` uses NavigationRail's indicator; `stripe` draws a left border on the selected icon.
-- **Selected**: `onSecondaryContainer` (icon/label)
-- **Unselected**: `onSurfaceVariant`
-- **Label style**: `labelMedium`
-- **Widths**: compact **≈64dp**, regular **≈80dp**, extended min **≈256dp**
-- **Icon size**: **24dp**
-- **Item padding**: from `spacing.sm/md`
-
-## Badges
-
-Use `badgeCount` for numeric badges or `badgeDot: true` for a small dot. Colors default to `errorContainer / onErrorContainer` and can be overridden via `RailBadgeM3E`.
-
-## Accessibility
-
-- Provide `semanticLabel` per destination (used as tooltip) or on the rail (`semanticLabel` on the widget).
-- Choose the label behavior to balance density with readability.
-
-## License
-
-MIT
+See the `/example` app for a runnable demo.