Frosted bottom bar: adjustable blur and opacity with Less/Default/More presets

Settings > Appearance shows a preset control plus Blur and Opacity sliders
(new NooSlider) while frosted glass is on; values persist and feed
NooBottomBar.frostedBlur/frostedOpacity. Default matches the old fixed look.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

.claude/context/styling.md

@@ -86,7 +86,7 @@ Catalog:
 
 | Folder | Components |
 |---|---|
-| `core/` | `NooButton`, `NooFab`, `NooChip`, `NooSegmentedControl`, `NooToggle`, `NooSearchField`, `NooAvatar`, `NooBadge`, `NooProgressBar` |
+| `core/` | `NooButton`, `NooFab`, `NooChip`, `NooSegmentedControl`, `NooToggle`, `NooSlider`, `NooSearchField`, `NooAvatar`, `NooBadge`, `NooProgressBar` |
 | `lists/` | `NooGroupedList`, `NooSettingsRow`, `NooTabOrderRow`, `NooBanner`, `NooInfoNote` (tinted info callout; `SettingsSection(notice:)`), `NooSummaryCard`, `NooSelectionBar` |
 | `files/` | `NooFileKind` (spec §1.2 tiles; `NooFileKind.from(name:, mimeType:, isDirectory:)`), `NooFileTile`, `NooStatusIcon`/`NooSyncStatus`, `NooFileRow` (mobile 64px), `NooFileTableHeader`/`NooFileTableRow` (desktop), `NooSwipeAction` |
 | `media/` | `NooGridCard`, `NooPhotoTile` (video badge, selection), `NooPhotoGroupHeader`/`NooPhotoGrid` (sliver, or `.box`), `NooActivityItem`, `NooStatCard` |
@@ -255,9 +255,16 @@ blocks are noted where they matter:
   only the attached bar still has a distinct iOS row. A separate, orthogonal
   `SettingsController.bottomBarFrosted` toggle (Settings → Appearance →
   "Frosted glass bottom bar", off by default, both platforms and both bar
-  styles) swaps the bar's solid `surface` for a 0.72-alpha one over a
+  styles) swaps the bar's solid `surface` for a translucent one over a
-  20-sigma `BackdropFilter` (same sigma as `FrostedGlassContainer`) and drops
+  `BackdropFilter` blur and drops
-  `nooDialogShadow` (it would show through the glass). A frosted bar only
+  `nooDialogShadow` (it would show through the glass). Strength is user-set:
+  `FrostedGlassPreset` Less (blur 10 / opacity 0.88), Default (20 / 0.72, the
+  old fixed values) and More (32 / 0.55), plus Blur (0-40) and Opacity
+  (0.3-1.0) sliders (`NooSlider`, `core/`) in Settings -> Appearance, shown
+  only while frosted glass is on; both persist
+  (`ui_bottom_bar_frosted_blur`/`_opacity`) and reach the bar as
+  `NooBottomBar.frostedBlur`/`frostedOpacity`. No preset is highlighted once
+  the sliders are moved off all three. A frosted bar only
   reads as glass with content behind it, so the shell uses
   `NooBottomBar.drawsBehindBody(barStyle, frosted)` for `extendBody`, and
   `bottomBarClearance` (and Files' own trailing sliver) reserve the bar's

lib/main.dart

@@ -564,6 +564,8 @@ class _MainShellViewState extends State<MainShellView> {
           style: navStyle,
           barStyle: bottomBarStyle,
           frosted: settings.bottomBarFrosted,
+          frostedBlur: settings.bottomBarFrostedBlur,
+          frostedOpacity: settings.bottomBarFrostedOpacity,
           tabs: pinnedTabs,
           selectedIndex: pinnedIndex,
           onSearchTap: showBottomBarSearch ? () => openSearch(context) : null,

lib/providers/settings_controller.dart

@@ -21,6 +21,30 @@ enum FabStyle { auto, mini, expanded }
 /// animated wave with a tick-mark thumb ([squiggly]).
 enum MediaProgressBarStyle { classic, wavy, slim, squiggly }
 
+/// The frosted-glass bottom bar's blur sigma and surface opacity, in three
+/// ready-made strengths (Settings, Appearance). Moving either slider off all
+/// three leaves no preset selected (a custom mix).
+enum FrostedGlassPreset {
+  less(blur: 10, opacity: 0.88, label: 'Less'),
+  standard(blur: 20, opacity: 0.72, label: 'Default'),
+  more(blur: 32, opacity: 0.55, label: 'More');
+
+  final double blur;
+  final double opacity;
+  final String label;
+
+  const FrostedGlassPreset({
+    required this.blur,
+    required this.opacity,
+    required this.label,
+  });
+}
+
+const double minFrostedBlur = 0;
+const double maxFrostedBlur = 40;
+const double minFrostedOpacity = 0.3;
+const double maxFrostedOpacity = 1.0;
+
 /// Global (not per-account) UI settings: theme, bottom-nav appearance, tab
 /// configuration, swipe actions. Independent of login state - these mean
 /// the same thing whether any account is signed in or not, unlike
@@ -39,6 +63,8 @@ class SettingsController extends ChangeNotifier {
   static const _prefFabStyle = 'ui_fab_style';
   static const _prefBottomBarStyle = 'ui_bottom_bar_style';
   static const _prefBottomBarFrosted = 'ui_bottom_bar_frosted';
+  static const _prefFrostedBlur = 'ui_bottom_bar_frosted_blur';
+  static const _prefFrostedOpacity = 'ui_bottom_bar_frosted_opacity';
   static const _prefNavMenuStyle = 'ui_nav_menu_style';
   static const _prefSearchInBottomBar = 'ui_search_in_bottom_bar';
   static const _prefAmoledDark = 'ui_amoled_dark';
@@ -53,6 +79,8 @@ class SettingsController extends ChangeNotifier {
   NooBottomBarStyle _bottomBarStyle = NooBottomBarStyle.attached;
   NooNavMenuStyle _navMenuStyle = NooNavMenuStyle.drawer;
   bool _bottomBarFrosted = false;
+  double _frostedBlur = FrostedGlassPreset.standard.blur;
+  double _frostedOpacity = FrostedGlassPreset.standard.opacity;
   bool _searchInBottomBar = false;
   bool _useDynamicColor = true;
   bool _amoledDark = false;
@@ -98,6 +126,14 @@ class SettingsController extends ChangeNotifier {
   ThemeMode get themeMode => _themeMode;
   NooBottomBarStyle get bottomBarStyle => _bottomBarStyle;
   bool get bottomBarFrosted => _bottomBarFrosted;
+  double get bottomBarFrostedBlur => _frostedBlur;
+  double get bottomBarFrostedOpacity => _frostedOpacity;
+
+  /// The preset the current blur/opacity match exactly, or null when the
+  /// sliders have been moved to something custom.
+  FrostedGlassPreset? get frostedPreset => FrostedGlassPreset.values
+      .where((p) => p.blur == _frostedBlur && p.opacity == _frostedOpacity)
+      .firstOrNull;
   NooNavMenuStyle get navMenuStyle => _navMenuStyle;
   bool get searchInBottomBar => _searchInBottomBar;
   bool get useDynamicColor => _useDynamicColor;
@@ -160,6 +196,15 @@ class SettingsController extends ChangeNotifier {
       }
       _bottomBarFrosted =
           prefs.getBool(_prefBottomBarFrosted) ?? _bottomBarFrosted;
+      _frostedBlur = (prefs.getDouble(_prefFrostedBlur) ?? _frostedBlur).clamp(
+        minFrostedBlur,
+        maxFrostedBlur,
+      );
+      _frostedOpacity =
+          (prefs.getDouble(_prefFrostedOpacity) ?? _frostedOpacity).clamp(
+            minFrostedOpacity,
+            maxFrostedOpacity,
+          );
       _searchInBottomBar =
           prefs.getBool(_prefSearchInBottomBar) ?? _searchInBottomBar;
       _useDynamicColor =
@@ -318,6 +363,27 @@ class SettingsController extends ChangeNotifier {
     _prefsFuture.then((p) => p.setString(_prefBottomBarStyle, style.name));
   }
 
+  void setFrostedBlur(double value) {
+    final v = value.clamp(minFrostedBlur, maxFrostedBlur);
+    if (_frostedBlur == v) return;
+    _frostedBlur = v;
+    notifyListeners();
+    _prefsFuture.then((p) => p.setDouble(_prefFrostedBlur, v));
+  }
+
+  void setFrostedOpacity(double value) {
+    final v = value.clamp(minFrostedOpacity, maxFrostedOpacity);
+    if (_frostedOpacity == v) return;
+    _frostedOpacity = v;
+    notifyListeners();
+    _prefsFuture.then((p) => p.setDouble(_prefFrostedOpacity, v));
+  }
+
+  void setFrostedPreset(FrostedGlassPreset preset) {
+    setFrostedBlur(preset.blur);
+    setFrostedOpacity(preset.opacity);
+  }
+
   void setBottomBarFrosted(bool value) {
     if (_bottomBarFrosted == value) return;
     _bottomBarFrosted = value;

lib/widgets/bottom_nav_bar.dart

@@ -17,6 +17,8 @@ class BottomNavBar extends StatelessWidget {
   final NooNavStyle style;
   final NooBottomBarStyle barStyle;
   final bool frosted;
+  final double frostedBlur;
+  final double frostedOpacity;
   final List<AppTab> tabs;
   final int selectedIndex;
   final ValueChanged<int> onDestinationSelected;
@@ -27,6 +29,8 @@ class BottomNavBar extends StatelessWidget {
     required this.style,
     this.barStyle = NooBottomBarStyle.attached,
     this.frosted = false,
+    this.frostedBlur = NooBottomBar.defaultFrostedBlur,
+    this.frostedOpacity = NooBottomBar.defaultFrostedOpacity,
     required this.tabs,
     required this.selectedIndex,
     required this.onDestinationSelected,
@@ -39,6 +43,8 @@ class BottomNavBar extends StatelessWidget {
       style: style,
       barStyle: barStyle,
       frosted: frosted,
+      frostedBlur: frostedBlur,
+      frostedOpacity: frostedOpacity,
       destinations: [
         for (final tab in tabs)
           NooNavDestination(icon: tab.icon, label: tab.label),

lib/widgets/noo/core/noo_slider.dart

@@ -0,0 +1,51 @@
+import 'package:flutter/material.dart';
+import '../../../theme/design_tokens.dart';
+
+/// A continuous (or [divisions]-stepped) value slider in the design system's
+/// colors: accent fill on a `surface3` track, accent thumb. Data-agnostic -
+/// the caller owns [value] and formats any readout beside it.
+class NooSlider extends StatelessWidget {
+  final double value;
+  final double min;
+  final double max;
+  final int? divisions;
+  final ValueChanged<double>? onChanged;
+  final String? semanticLabel;
+
+  const NooSlider({
+    super.key,
+    required this.value,
+    required this.min,
+    required this.max,
+    this.divisions,
+    this.onChanged,
+    this.semanticLabel,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final colors = context.nooColors;
+    return SliderTheme(
+      data: SliderTheme.of(context).copyWith(
+        trackHeight: 4,
+        activeTrackColor: colors.accent,
+        inactiveTrackColor: colors.surface3,
+        thumbColor: colors.accent,
+        overlayColor: colors.accent.withValues(alpha: 0.12),
+        thumbShape: const RoundSliderThumbShape(enabledThumbRadius: 9),
+        trackShape: const RoundedRectSliderTrackShape(),
+        showValueIndicator: ShowValueIndicator.never,
+      ),
+      child: Slider(
+        value: value.clamp(min, max),
+        min: min,
+        max: max,
+        divisions: divisions,
+        semanticFormatterCallback: semanticLabel == null
+            ? null
+            : (v) => '$semanticLabel ${v.toStringAsFixed(2)}',
+        onChanged: onChanged,
+      ),
+    );
+  }
+}

lib/widgets/noo/nav/noo_bottom_bar.dart

@@ -14,11 +14,6 @@ const double _kFloatingPillTop = 8;
 const double _kAndroidPillWidth = 56;
 const double _kAndroidPillHeight = 32;
 
-/// Frosted glass: the surface fill's opacity and the backdrop blur sigma -
-/// the same sigma [FrostedGlassContainer] uses for the media viewer chrome.
-const double _kFrostedAlpha = 0.72;
-const double _kFrostedSigma = 20;
-
 /// The mobile bottom bar (DESIGN_SYSTEM.md 3, "Mobile"; `iNav`/`aNav` in
 /// `Mobile Screen.dc.html`). Shows the 5 pinned tabs - which ones, and in
 /// what order, is the caller's business; this only draws [destinations].
@@ -71,6 +66,12 @@ class NooBottomBar extends StatelessWidget {
   final NooNavStyle style;
   final NooBottomBarStyle barStyle;
   final bool frosted;
+
+  /// Backdrop blur sigma and surface-fill opacity while [frosted] (user-
+  /// adjustable in Settings; the defaults match [FrostedGlassContainer]'s
+  /// blur).
+  final double frostedBlur;
+  final double frostedOpacity;
   final List<NooNavDestination> destinations;
   final int selectedIndex;
   final ValueChanged<int> onSelected;
@@ -82,6 +83,8 @@ class NooBottomBar extends StatelessWidget {
     required this.style,
     this.barStyle = NooBottomBarStyle.attached,
     this.frosted = false,
+    this.frostedBlur = defaultFrostedBlur,
+    this.frostedOpacity = defaultFrostedOpacity,
     required this.destinations,
     required this.selectedIndex,
     required this.onSelected,
@@ -99,6 +102,9 @@ class NooBottomBar extends StatelessWidget {
     return barStyle == NooBottomBarStyle.floating ? 64 : 80;
   }
 
+  static const double defaultFrostedBlur = 20;
+  static const double defaultFrostedOpacity = 0.72;
+
   /// Whether the host `Scaffold` must draw its body behind the bar
   /// (`extendBody`) - true for floating (its transparent margin) and for any
   /// frosted bar (there's nothing to blur otherwise).
@@ -144,7 +150,9 @@ class NooBottomBar extends StatelessWidget {
         ),
         child: row,
       );
-      final pill = frosted ? _blurred(pillBox, pillRadius) : pillBox;
+      final pill = frosted
+          ? _blurred(pillBox, pillRadius, frostedBlur)
+          : pillBox;
       return SafeArea(
         top: false,
         child: Padding(
@@ -176,6 +184,8 @@ class NooBottomBar extends StatelessWidget {
                         onTap: onSearchTap!,
                         size: barHeight,
                         frosted: frosted,
+                        frostedBlur: frostedBlur,
+                        frostedOpacity: frostedOpacity,
                       ),
                     ],
                   ),
@@ -195,11 +205,11 @@ class NooBottomBar extends StatelessWidget {
         child: SizedBox(height: barHeight, child: row),
       ),
     );
-    return frosted ? _blurred(bar, BorderRadius.zero) : bar;
+    return frosted ? _blurred(bar, BorderRadius.zero, frostedBlur) : bar;
   }
 
   Color _fill(NooColors colors) => frosted
-      ? colors.surface.withValues(alpha: _kFrostedAlpha)
+      ? colors.surface.withValues(alpha: frostedOpacity)
       : colors.surface;
 
   Widget _buildIosRow({NooNavDestination? trailingSearch}) {
@@ -286,10 +296,10 @@ class NooBottomBar extends StatelessWidget {
 
 /// Clips [child] to [radius] and blurs whatever is drawn behind it - the
 /// frosted bar's backdrop. [child] supplies the translucent fill on top.
-Widget _blurred(Widget child, BorderRadius radius) => ClipRRect(
+Widget _blurred(Widget child, BorderRadius radius, double sigma) => ClipRRect(
   borderRadius: radius,
   child: BackdropFilter(
-    filter: ImageFilter.blur(sigmaX: _kFrostedSigma, sigmaY: _kFrostedSigma),
+    filter: ImageFilter.blur(sigmaX: sigma, sigmaY: sigma),
     child: child,
   ),
 );
@@ -302,12 +312,16 @@ class _SearchSatellite extends StatelessWidget {
   final VoidCallback onTap;
   final double size;
   final bool frosted;
+  final double frostedBlur;
+  final double frostedOpacity;
 
   const _SearchSatellite({
     required this.destination,
     required this.onTap,
     required this.size,
     required this.frosted,
+    required this.frostedBlur,
+    required this.frostedOpacity,
   });
 
   @override
@@ -331,7 +345,7 @@ class _SearchSatellite extends StatelessWidget {
       alignment: Alignment.center,
       decoration: BoxDecoration(
         color: frosted
-            ? colors.surface.withValues(alpha: _kFrostedAlpha)
+            ? colors.surface.withValues(alpha: frostedOpacity)
             : colors.surface,
         border: Border.all(color: colors.line),
         shape: BoxShape.circle,
@@ -339,7 +353,9 @@ class _SearchSatellite extends StatelessWidget {
       ),
       child: Icon(destination.icon, size: 24, color: colors.fg1),
     );
-    return frosted ? _blurred(disc, BorderRadius.circular(size / 2)) : disc;
+    return frosted
+        ? _blurred(disc, BorderRadius.circular(size / 2), frostedBlur)
+        : disc;
   }
 }
 

lib/widgets/settings/settings_appearance.dart

@@ -5,6 +5,7 @@ import '../../providers/settings_controller.dart';
 import '../../theme/app_theme.dart';
 import '../../theme/design_tokens.dart';
 import '../noo/core/noo_segmented_control.dart';
+import '../noo/core/noo_slider.dart';
 import '../noo/core/noo_toggle.dart';
 import '../noo/lists/noo_settings_row.dart';
 import '../noo/nav/noo_nav_style.dart';
@@ -64,6 +65,7 @@ class SettingsAppearanceSection extends StatelessWidget {
                 onChanged: settings.setBottomBarFrosted,
               ),
             ),
+            if (settings.bottomBarFrosted) _FrostedGlassRow(settings: settings),
             _NavMenuStyleRow(settings: settings),
             NooSettingsRow(
               icon: LucideIcons.search,
@@ -251,6 +253,117 @@ class _BottomBarStyleRow extends StatelessWidget {
   }
 }
 
+/// How strong the frosted-glass bottom bar looks: three presets for a quick
+/// pick, and the blur / opacity sliders they set, for anything in between.
+/// Only shown while frosted glass is on.
+class _FrostedGlassRow extends StatelessWidget {
+  final SettingsController settings;
+
+  const _FrostedGlassRow({required this.settings});
+
+  @override
+  Widget build(BuildContext context) {
+    final colors = context.nooColors;
+    return Material(
+      color: colors.surface,
+      child: Padding(
+        padding: const EdgeInsets.symmetric(
+          horizontal: NooSpace.md,
+          vertical: 12,
+        ),
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            Row(
+              children: [
+                Icon(LucideIcons.sparkles, size: 20, color: colors.fg2),
+                const SizedBox(width: 14),
+                Text(
+                  'Frost strength',
+                  style: NooText.bodyL.copyWith(color: colors.fg1),
+                ),
+              ],
+            ),
+            const SizedBox(height: 12),
+            NooSegmentedControl<FrostedGlassPreset?>(
+              fill: true,
+              // No segment selected once the sliders no longer match a preset.
+              value: settings.frostedPreset,
+              onChanged: (preset) {
+                if (preset != null) settings.setFrostedPreset(preset);
+              },
+              options: [
+                for (final preset in FrostedGlassPreset.values)
+                  NooSegmentOption<FrostedGlassPreset?>(
+                    value: preset,
+                    label: preset.label,
+                  ),
+              ],
+            ),
+            const SizedBox(height: 8),
+            _SliderLine(
+              label: 'Blur',
+              readout: settings.bottomBarFrostedBlur.round().toString(),
+              slider: NooSlider(
+                value: settings.bottomBarFrostedBlur,
+                min: minFrostedBlur,
+                max: maxFrostedBlur,
+                semanticLabel: 'Blur',
+                onChanged: settings.setFrostedBlur,
+              ),
+            ),
+            _SliderLine(
+              label: 'Opacity',
+              readout: '${(settings.bottomBarFrostedOpacity * 100).round()}%',
+              slider: NooSlider(
+                value: settings.bottomBarFrostedOpacity,
+                min: minFrostedOpacity,
+                max: maxFrostedOpacity,
+                semanticLabel: 'Opacity',
+                onChanged: settings.setFrostedOpacity,
+              ),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}
+
+class _SliderLine extends StatelessWidget {
+  final String label;
+  final String readout;
+  final Widget slider;
+
+  const _SliderLine({
+    required this.label,
+    required this.readout,
+    required this.slider,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final colors = context.nooColors;
+    return Row(
+      children: [
+        SizedBox(
+          width: 64,
+          child: Text(label, style: NooText.body.copyWith(color: colors.fg2)),
+        ),
+        Expanded(child: slider),
+        SizedBox(
+          width: 44,
+          child: Text(
+            readout,
+            textAlign: TextAlign.end,
+            style: NooText.body.copyWith(color: colors.fg3),
+          ),
+        ),
+      ],
+    );
+  }
+}
+
 /// "Navigation menu" (Settings → Appearance): which widget opens hidden
 /// tabs + Settings - the original `menu` icon that opens a left `Drawer`,
 /// or the avatar button instead (opens `showAvatarMenu`, a dropdown

test/providers/settings_frosted_test.dart

@@ -0,0 +1,85 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+import 'package:noo/providers/settings_controller.dart';
+
+/// The frosted-glass bottom bar's blur/opacity settings and their presets.
+void main() {
+  TestWidgetsFlutterBinding.ensureInitialized();
+
+  setUp(() => SharedPreferences.setMockInitialValues({}));
+
+  Future<SettingsController> build() async {
+    final settings = SettingsController();
+    // `_load` is async and not exposed; one event-loop turn lets it finish.
+    await Future<void>.delayed(Duration.zero);
+    return settings;
+  }
+
+  test('starts on the Default preset', () async {
+    final settings = await build();
+    expect(settings.frostedPreset, FrostedGlassPreset.standard);
+    expect(settings.bottomBarFrostedBlur, 20);
+    expect(settings.bottomBarFrostedOpacity, 0.72);
+  });
+
+  test('presets set both values and are recognised again', () async {
+    final settings = await build();
+    for (final preset in FrostedGlassPreset.values) {
+      settings.setFrostedPreset(preset);
+      expect(settings.bottomBarFrostedBlur, preset.blur);
+      expect(settings.bottomBarFrostedOpacity, preset.opacity);
+      expect(settings.frostedPreset, preset);
+    }
+  });
+
+  test('presets run from lighter to stronger frosting', () {
+    expect(
+      FrostedGlassPreset.less.blur,
+      lessThan(FrostedGlassPreset.standard.blur),
+    );
+    expect(
+      FrostedGlassPreset.standard.blur,
+      lessThan(FrostedGlassPreset.more.blur),
+    );
+    expect(
+      FrostedGlassPreset.less.opacity,
+      greaterThan(FrostedGlassPreset.standard.opacity),
+    );
+    expect(
+      FrostedGlassPreset.standard.opacity,
+      greaterThan(FrostedGlassPreset.more.opacity),
+    );
+  });
+
+  test('moving a slider off every preset leaves none selected', () async {
+    final settings = await build();
+    settings.setFrostedBlur(27);
+    expect(settings.frostedPreset, isNull);
+    settings.setFrostedBlur(FrostedGlassPreset.standard.blur);
+    expect(settings.frostedPreset, FrostedGlassPreset.standard);
+  });
+
+  test('values are clamped to their ranges', () async {
+    final settings = await build();
+    settings
+      ..setFrostedBlur(500)
+      ..setFrostedOpacity(0);
+    expect(settings.bottomBarFrostedBlur, maxFrostedBlur);
+    expect(settings.bottomBarFrostedOpacity, minFrostedOpacity);
+    settings
+      ..setFrostedBlur(-3)
+      ..setFrostedOpacity(9);
+    expect(settings.bottomBarFrostedBlur, minFrostedBlur);
+    expect(settings.bottomBarFrostedOpacity, maxFrostedOpacity);
+  });
+
+  test('saved values are restored (and clamped) on the next launch', () async {
+    SharedPreferences.setMockInitialValues({
+      'ui_bottom_bar_frosted_blur': 32.0,
+      'ui_bottom_bar_frosted_opacity': 7.0,
+    });
+    final settings = await build();
+    expect(settings.bottomBarFrostedBlur, 32);
+    expect(settings.bottomBarFrostedOpacity, maxFrostedOpacity);
+  });
+}

test/widgets/noo/core_test.dart

@@ -10,6 +10,7 @@ import 'package:noo/widgets/noo/core/noo_chip.dart';
 import 'package:noo/widgets/noo/core/noo_fab.dart';
 import 'package:noo/widgets/noo/core/noo_progress_bar.dart';
 import 'package:noo/widgets/noo/core/noo_search_field.dart';
+import 'package:noo/widgets/noo/core/noo_slider.dart';
 import 'package:noo/widgets/noo/core/noo_segmented_control.dart';
 import 'package:noo/widgets/noo/core/noo_toggle.dart';
 import 'package:noo/widgets/noo/nav/noo_nav_style.dart';
@@ -98,6 +99,35 @@ void main() {
     }
   });
 
+  group('NooSlider', () {
+    testNooWidgets('dragging reports a value within min..max', (
+      tester,
+      theme,
+      c,
+    ) async {
+      var value = 10.0;
+      await pumpNoo(
+        tester,
+        StatefulBuilder(
+          builder: (context, setState) => SizedBox(
+            width: 300,
+            child: NooSlider(
+              value: value,
+              min: 0,
+              max: 40,
+              onChanged: (v) => setState(() => value = v),
+            ),
+          ),
+        ),
+        theme: theme,
+      );
+      await tester.drag(find.byType(Slider), const Offset(150, 0));
+      await tester.pump();
+      expect(value, greaterThan(10));
+      expect(value, lessThanOrEqualTo(40));
+    });
+  });
+
   group('NooAvatar', () {
     testNooWidgets('current user uses accent-soft/accent-text', (
       tester,

test/widgets/noo/nav_test.dart

@@ -1,3 +1,4 @@
+import 'dart:ui' show ImageFilter;
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:lucide_icons_flutter/lucide_icons.dart';
@@ -62,6 +63,44 @@ void main() {
       }
     }
 
+    testNooWidgets('frosted bar uses the given blur sigma and fill opacity', (
+      tester,
+      theme,
+      c,
+    ) async {
+      await pumpNoo(
+        tester,
+        SizedBox(
+          width: 360,
+          height: 120,
+          child: NooBottomBar(
+            style: NooNavStyle.android,
+            frosted: true,
+            frostedBlur: 31,
+            frostedOpacity: 0.5,
+            destinations: _destinations,
+            selectedIndex: 0,
+            onSelected: (_) {},
+          ),
+        ),
+        theme: theme,
+      );
+      expect(
+        tester.widget<BackdropFilter>(find.byType(BackdropFilter)).filter,
+        ImageFilter.blur(sigmaX: 31, sigmaY: 31),
+      );
+      expect(
+        find.byWidgetPredicate(
+          (w) =>
+              w is Container &&
+              w.decoration is BoxDecoration &&
+              (w.decoration as BoxDecoration).color ==
+                  c.surface.withValues(alpha: 0.5),
+        ),
+        findsOneWidget,
+      );
+    });
+
     test('drawsBehindBody: floating or frosted', () {
       expect(
         NooBottomBar.drawsBehindBody(NooBottomBarStyle.attached, false),