refactor tab bar behaviour; respect scroll preferences of websites;

app/lib/features/geckoview/domain/entities/states/tab.dart

@@ -64,6 +64,7 @@ class TabState extends WebPageInfo {
   final bool isPrivate;
   final bool isFullScreen;
   final bool isLoading;
+  final bool showToolbarAsExpanded;
 
   bool get isFinishedLoading => !isLoading && progress == 100;
 
@@ -84,6 +85,7 @@ class TabState extends WebPageInfo {
     required this.isPrivate,
     required this.isFullScreen,
     required this.isLoading,
+    required this.showToolbarAsExpanded,
     required this.securityInfoState,
     required this.historyState,
     required this.readerableState,
@@ -102,6 +104,7 @@ class TabState extends WebPageInfo {
     isPrivate: false,
     isFullScreen: false,
     isLoading: false,
+    showToolbarAsExpanded: false,
     securityInfoState: SecurityState.$default(),
     historyState: HistoryState.$default(),
     readerableState: ReaderableState.$default(),
@@ -120,6 +123,7 @@ class TabState extends WebPageInfo {
     isPrivate,
     isFullScreen,
     isLoading,
+    showToolbarAsExpanded,
     securityInfoState,
     historyState,
     readerableState,

app/lib/features/geckoview/domain/entities/states/tab.g.dart

@@ -27,6 +27,8 @@ abstract class _$TabStateCWProxy {
 
   TabState isLoading(bool isLoading);
 
+  TabState showToolbarAsExpanded(bool showToolbarAsExpanded);
+
   TabState securityInfoState(SecurityState securityInfoState);
 
   TabState historyState(HistoryState historyState);
@@ -53,6 +55,7 @@ abstract class _$TabStateCWProxy {
     bool isPrivate,
     bool isFullScreen,
     bool isLoading,
+    bool showToolbarAsExpanded,
     SecurityState securityInfoState,
     HistoryState historyState,
     ReaderableState readerableState,
@@ -97,6 +100,10 @@ class _$TabStateCWProxyImpl implements _$TabStateCWProxy {
   @override
   TabState isLoading(bool isLoading) => call(isLoading: isLoading);
 
+  @override
+  TabState showToolbarAsExpanded(bool showToolbarAsExpanded) =>
+      call(showToolbarAsExpanded: showToolbarAsExpanded);
+
   @override
   TabState securityInfoState(SecurityState securityInfoState) =>
       call(securityInfoState: securityInfoState);
@@ -132,6 +139,7 @@ class _$TabStateCWProxyImpl implements _$TabStateCWProxy {
     Object? isPrivate = const $CopyWithPlaceholder(),
     Object? isFullScreen = const $CopyWithPlaceholder(),
     Object? isLoading = const $CopyWithPlaceholder(),
+    Object? showToolbarAsExpanded = const $CopyWithPlaceholder(),
     Object? securityInfoState = const $CopyWithPlaceholder(),
     Object? historyState = const $CopyWithPlaceholder(),
     Object? readerableState = const $CopyWithPlaceholder(),
@@ -180,6 +188,12 @@ class _$TabStateCWProxyImpl implements _$TabStateCWProxy {
           ? _value.isLoading
           // ignore: cast_nullable_to_non_nullable
           : isLoading as bool,
+      showToolbarAsExpanded:
+          showToolbarAsExpanded == const $CopyWithPlaceholder() ||
+              showToolbarAsExpanded == null
+          ? _value.showToolbarAsExpanded
+          // ignore: cast_nullable_to_non_nullable
+          : showToolbarAsExpanded as bool,
       securityInfoState:
           securityInfoState == const $CopyWithPlaceholder() ||
               securityInfoState == null

app/lib/features/geckoview/domain/providers/tab_state.dart

@@ -87,6 +87,7 @@ class TabStates extends _$TabStates {
       isPrivate: contentState.isPrivate,
       isFullScreen: contentState.isFullScreen,
       isLoading: contentState.isLoading,
+      showToolbarAsExpanded: contentState.showToolbarAsExpanded,
     );
 
     _updateState({...state}..[contentState.id] = newState);

app/lib/features/geckoview/domain/providers/tab_state.g.dart

@@ -41,7 +41,7 @@ final class TabStatesProvider
   }
 }
 
-String _$tabStatesHash() => r'985d2eb87c59c3a113b8bbcf9d96267c42a2f543';
+String _$tabStatesHash() => r'975de1242f42e2017754dc560125788b83ad8b72';
 
 abstract class _$TabStates extends $Notifier<Map<String, TabState>> {
   Map<String, TabState> build();

app/lib/features/geckoview/features/browser/presentation/controllers/tab_bar_dismissable.dart

@@ -1,40 +0,0 @@
-/*
- * Copyright (c) 2024-2026 Fabian Freund.
- *
- * This file is part of WebLibre
- * (see https://weblibre.eu).
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Affero General Public License as
- * published by the Free Software Foundation, either version 3 of the
- * License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU Affero General Public License for more details.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-import 'package:riverpod_annotation/riverpod_annotation.dart';
-
-part 'tab_bar_dismissable.g.dart';
-
-@Riverpod(keepAlive: true)
-class TabBarDismissableController extends _$TabBarDismissableController {
-  void show() {
-    state = false;
-  }
-
-  void dismiss() {
-    if (!state) {
-      state = true;
-    }
-  }
-
-  @override
-  bool build() {
-    return false;
-  }
-}

app/lib/features/geckoview/features/browser/presentation/controllers/tab_bar_dismissable.g.dart

@@ -1,64 +0,0 @@
-// GENERATED CODE - DO NOT MODIFY BY HAND
-
-part of 'tab_bar_dismissable.dart';
-
-// **************************************************************************
-// RiverpodGenerator
-// **************************************************************************
-
-// GENERATED CODE - DO NOT MODIFY BY HAND
-// ignore_for_file: type=lint, type=warning
-
-@ProviderFor(TabBarDismissableController)
-final tabBarDismissableControllerProvider =
-    TabBarDismissableControllerProvider._();
-
-final class TabBarDismissableControllerProvider
-    extends $NotifierProvider<TabBarDismissableController, bool> {
-  TabBarDismissableControllerProvider._()
-    : super(
-        from: null,
-        argument: null,
-        retry: null,
-        name: r'tabBarDismissableControllerProvider',
-        isAutoDispose: false,
-        dependencies: null,
-        $allTransitiveDependencies: null,
-      );
-
-  @override
-  String debugGetCreateSourceHash() => _$tabBarDismissableControllerHash();
-
-  @$internal
-  @override
-  TabBarDismissableController create() => TabBarDismissableController();
-
-  /// {@macro riverpod.override_with_value}
-  Override overrideWithValue(bool value) {
-    return $ProviderOverride(
-      origin: this,
-      providerOverride: $SyncValueProvider<bool>(value),
-    );
-  }
-}
-
-String _$tabBarDismissableControllerHash() =>
-    r'e0c2f700ccebc35bc8029370cdebd63e98bf95e1';
-
-abstract class _$TabBarDismissableController extends $Notifier<bool> {
-  bool build();
-  @$mustCallSuper
-  @override
-  void runBuild() {
-    final ref = this.ref as $Ref<bool, bool>;
-    final element =
-        ref.element
-            as $ClassProviderElement<
-              AnyNotifier<bool, bool>,
-              bool,
-              Object?,
-              Object?
-            >;
-    element.handleCreate(ref, build);
-  }
-}

app/lib/features/geckoview/features/browser/presentation/controllers/toolbar_visibility.dart

@@ -0,0 +1,108 @@
+/*
+ * Copyright (c) 2024-2026 Fabian Freund.
+ *
+ * This file is part of WebLibre
+ * (see https://weblibre.eu).
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+import 'package:riverpod/riverpod.dart';
+import 'package:riverpod_annotation/riverpod_annotation.dart';
+import 'package:weblibre/features/geckoview/domain/providers.dart';
+import 'package:weblibre/features/geckoview/domain/providers/tab_state.dart';
+import 'package:weblibre/features/user/domain/repositories/general_settings.dart';
+
+part 'toolbar_visibility.g.dart';
+
+enum ToolbarVisibility { visible, hidden, dismissed }
+
+@Riverpod(keepAlive: true)
+class ToolbarVisibilityController extends _$ToolbarVisibilityController {
+  @override
+  ToolbarVisibility build(String? tabId) {
+    // Show toolbar when loading starts
+    ref.listen(tabStatesProvider.select((tabs) => tabs[tabId]?.isLoading), (
+      previous,
+      next,
+    ) {
+      if (!ref.read(generalSettingsWithDefaultsProvider).autoHideTabBar) {
+        return;
+      }
+      if (next == true) {
+        show();
+      }
+    });
+
+    // Show toolbar on navigation (history state change)
+    ref.listen(tabStatesProvider.select((tabs) => tabs[tabId]?.historyState), (
+      previous,
+      next,
+    ) {
+      if (!ref.read(generalSettingsWithDefaultsProvider).autoHideTabBar) {
+        return;
+      }
+      if (next != null && previous != null && previous != next) {
+        show();
+      }
+    });
+
+    // Force-show when GeckoView requests toolbar expansion
+    // (e.g. touch on form input)
+    ref.listen<bool>(
+      tabStatesProvider.select(
+        (tabs) => tabs[tabId]?.showToolbarAsExpanded ?? false,
+      ),
+      (previous, next) {
+        if (next && previous != next) {
+          forceShow();
+        }
+      },
+    );
+
+    return ToolbarVisibility.visible;
+  }
+
+  /// Hide toolbar via scroll. All guards checked internally.
+  void requestHide() {
+    final settings = ref.read(generalSettingsWithDefaultsProvider);
+    if (!settings.autoHideTabBar) return;
+
+    final isLoading = ref.read(tabStatesProvider)[tabId]?.isLoading ?? false;
+    if (isLoading) return;
+
+    final viewportService = ref.read(viewportServiceProvider);
+    if (!viewportService.isBrowserHandlingScrollEnabled) return;
+
+    if (state == ToolbarVisibility.dismissed) return;
+
+    state = ToolbarVisibility.hidden;
+  }
+
+  /// Show toolbar (scroll-up, tab change, loading start, etc).
+  /// Won't show if manually dismissed — use forceShow() for that.
+  void show() {
+    if (state == ToolbarVisibility.dismissed) return;
+    state = ToolbarVisibility.visible;
+  }
+
+  /// Force-show unconditionally + un-dismiss.
+  void forceShow() {
+    state = ToolbarVisibility.visible;
+  }
+
+  /// Dismiss toolbar (user swipe). Only affects this tab.
+  void dismiss() {
+    state = ToolbarVisibility.dismissed;
+  }
+}

app/lib/features/geckoview/features/browser/presentation/controllers/toolbar_visibility.g.dart

@@ -0,0 +1,111 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'toolbar_visibility.dart';
+
+// **************************************************************************
+// RiverpodGenerator
+// **************************************************************************
+
+// GENERATED CODE - DO NOT MODIFY BY HAND
+// ignore_for_file: type=lint, type=warning
+
+@ProviderFor(ToolbarVisibilityController)
+final toolbarVisibilityControllerProvider =
+    ToolbarVisibilityControllerFamily._();
+
+final class ToolbarVisibilityControllerProvider
+    extends $NotifierProvider<ToolbarVisibilityController, ToolbarVisibility> {
+  ToolbarVisibilityControllerProvider._({
+    required ToolbarVisibilityControllerFamily super.from,
+    required String? super.argument,
+  }) : super(
+         retry: null,
+         name: r'toolbarVisibilityControllerProvider',
+         isAutoDispose: false,
+         dependencies: null,
+         $allTransitiveDependencies: null,
+       );
+
+  @override
+  String debugGetCreateSourceHash() => _$toolbarVisibilityControllerHash();
+
+  @override
+  String toString() {
+    return r'toolbarVisibilityControllerProvider'
+        ''
+        '($argument)';
+  }
+
+  @$internal
+  @override
+  ToolbarVisibilityController create() => ToolbarVisibilityController();
+
+  /// {@macro riverpod.override_with_value}
+  Override overrideWithValue(ToolbarVisibility value) {
+    return $ProviderOverride(
+      origin: this,
+      providerOverride: $SyncValueProvider<ToolbarVisibility>(value),
+    );
+  }
+
+  @override
+  bool operator ==(Object other) {
+    return other is ToolbarVisibilityControllerProvider &&
+        other.argument == argument;
+  }
+
+  @override
+  int get hashCode {
+    return argument.hashCode;
+  }
+}
+
+String _$toolbarVisibilityControllerHash() =>
+    r'242449893afd6780d977544659e83d4641c8a0ad';
+
+final class ToolbarVisibilityControllerFamily extends $Family
+    with
+        $ClassFamilyOverride<
+          ToolbarVisibilityController,
+          ToolbarVisibility,
+          ToolbarVisibility,
+          ToolbarVisibility,
+          String?
+        > {
+  ToolbarVisibilityControllerFamily._()
+    : super(
+        retry: null,
+        name: r'toolbarVisibilityControllerProvider',
+        dependencies: null,
+        $allTransitiveDependencies: null,
+        isAutoDispose: false,
+      );
+
+  ToolbarVisibilityControllerProvider call(String? tabId) =>
+      ToolbarVisibilityControllerProvider._(argument: tabId, from: this);
+
+  @override
+  String toString() => r'toolbarVisibilityControllerProvider';
+}
+
+abstract class _$ToolbarVisibilityController
+    extends $Notifier<ToolbarVisibility> {
+  late final _$args = ref.$arg as String?;
+  String? get tabId => _$args;
+
+  ToolbarVisibility build(String? tabId);
+  @$mustCallSuper
+  @override
+  void runBuild() {
+    final ref = this.ref as $Ref<ToolbarVisibility, ToolbarVisibility>;
+    final element =
+        ref.element
+            as $ClassProviderElement<
+              AnyNotifier<ToolbarVisibility, ToolbarVisibility>,
+              ToolbarVisibility,
+              Object?,
+              Object?
+            >;
+    element.handleCreate(ref, () => build(_$args));
+  }
+}

app/lib/features/geckoview/features/browser/presentation/screens/browser.dart

@@ -39,7 +39,7 @@ import 'package:weblibre/features/geckoview/domain/providers/tab_session.dart';
 import 'package:weblibre/features/geckoview/domain/providers/tab_state.dart';
 import 'package:weblibre/features/geckoview/domain/repositories/tab.dart';
 import 'package:weblibre/features/geckoview/features/browser/domain/entities/sheet.dart';
-import 'package:weblibre/features/geckoview/features/browser/presentation/controllers/tab_bar_dismissable.dart';
+import 'package:weblibre/features/geckoview/features/browser/presentation/controllers/toolbar_visibility.dart';
 import 'package:weblibre/features/geckoview/features/browser/presentation/controllers/tab_view_controllers.dart';
 import 'package:weblibre/features/geckoview/features/browser/presentation/dialogs/keep_tab_dialog.dart';
 import 'package:weblibre/features/geckoview/features/browser/presentation/widgets/browser_modules/bottom_app_bar.dart';
@@ -136,7 +136,6 @@ class _TabBar extends HookConsumerWidget {
   final bool showMainToolbar;
   final bool showContextualToolbar;
   final bool showQuickTabSwitcherBar;
-  final ValueNotifier<bool> displayAppBar;
   final Stream<Offset>? pointerMoveEvents;
   final TabBarPosition tabBarPosition;
 
@@ -144,7 +143,6 @@ class _TabBar extends HookConsumerWidget {
     required this.showMainToolbar,
     required this.showContextualToolbar,
     required this.showQuickTabSwitcherBar,
-    required this.displayAppBar,
     required this.tabBarPosition,
     required this.pointerMoveEvents,
   });
@@ -154,30 +152,34 @@ class _TabBar extends HookConsumerWidget {
     final tabId = ref.watch(selectedTabProvider);
     final displayedSheet = ref.watch(bottomSheetControllerProvider);
 
-    final autoHideTabBar = ref.watch(
-      generalSettingsWithDefaultsProvider.select(
-        (value) => value.autoHideTabBar,
-      ),
-    );
-
     // Auto-hide scroll detection hooks (run unconditionally per hook rules)
     final diffAcc = useRef(0.0);
 
-    void resetHiddenState() {
+    // Reset scroll accumulator on tab switch
-      if (!ref.read(tabBarDismissableControllerProvider)) {
+    useEffect(() {
-        displayAppBar.value = true;
+      diffAcc.value = 0.0;
+      return null;
+    }, [tabId]);
+
+    // Reset scroll accumulator when controller shows toolbar
+    // (covers: loading start, navigation, showToolbarAsExpanded, forceShow)
+    ref.listen(toolbarVisibilityControllerProvider(tabId), (previous, next) {
+      if (next == ToolbarVisibility.visible && previous != next) {
+        diffAcc.value = 0.0;
       }
+    });
+
+    void resetHiddenState() {
+      ref
+          .read(
+            toolbarVisibilityControllerProvider(
+              ref.read(selectedTabProvider),
+            ).notifier,
+          )
+          .show();
       diffAcc.value = 0.0;
     }
 
-    useEffect(() {
-      if (!autoHideTabBar) return null;
-      WidgetsBinding.instance.addPostFrameCallback((_) {
-        resetHiddenState();
-      });
-      return null;
-    }, [tabId, autoHideTabBar]);
-
     useOnAppLifecycleStateChange((previous, current) {
       if (!ref.read(generalSettingsWithDefaultsProvider).autoHideTabBar) return;
       if (current == AppLifecycleState.resumed) {
@@ -185,38 +187,13 @@ class _TabBar extends HookConsumerWidget {
       }
     });
 
-    ref.listen(tabStateProvider(tabId).select((value) => value?.isLoading), (
-      previous,
-      next,
-    ) {
-      if (!ref.read(generalSettingsWithDefaultsProvider).autoHideTabBar) return;
-      if (next == true) {
-        resetHiddenState();
-      }
-    });
-
-    ref.listen(tabStateProvider(tabId).select((value) => value?.historyState), (
-      previous,
-      next,
-    ) {
-      if (!ref.read(generalSettingsWithDefaultsProvider).autoHideTabBar) return;
-      if (next != null && previous != null) {
-        if (previous != next) {
-          resetHiddenState();
-        }
-      }
-    });
-
     useOnStreamChange(
       pointerMoveEvents,
       onData: (event) {
-        if (!ref.read(generalSettingsWithDefaultsProvider).autoHideTabBar) {
+        final autoHide = ref
-          return;
+            .read(generalSettingsWithDefaultsProvider)
-        }
+            .autoHideTabBar;
-        // Don't apply auto-hide when toolbar is manually dismissed
+        if (!autoHide) return;
-        if (ref.read(tabBarDismissableControllerProvider)) {
-          return;
-        }
 
         final diff = event.dy;
         if (diff < 0) {
@@ -225,7 +202,13 @@ class _TabBar extends HookConsumerWidget {
           }
           diffAcc.value += diff;
           if (diffAcc.value.abs() > kToolbarHeight * 1.5) {
-            displayAppBar.value = false;
+            ref
+                .read(
+                  toolbarVisibilityControllerProvider(
+                    ref.read(selectedTabProvider),
+                  ).notifier,
+                )
+                .requestHide();
           }
         } else if (diff > 0) {
           if (diffAcc.value < 0) {
@@ -267,6 +250,9 @@ class BrowserScreen extends HookConsumerWidget {
     final tabInFullScreen = ref.watch(
       selectedTabStateProvider.select((value) => value?.isFullScreen ?? false),
     );
+    final tabIsLoading = ref.watch(
+      selectedTabStateProvider.select((value) => value?.isLoading ?? false),
+    );
 
     final overlayController = useOverlayPortalController();
 
@@ -300,12 +286,6 @@ class BrowserScreen extends HookConsumerWidget {
       ),
     );
 
-    final displayAppBar = useValueNotifier(true);
-
-    ref.listen(tabBarDismissableControllerProvider, (previous, next) {
-      displayAppBar.value = !next;
-    });
-
     ref.listen(overlayControllerProvider, (previous, next) {
       if (next != null) {
         overlayController.show();
@@ -330,14 +310,19 @@ class BrowserScreen extends HookConsumerWidget {
     final sheetDisplayed = displayedSheet != null;
 
     // Compute visibility states for toolbars
-    final appBarVisible = useValueListenable(displayAppBar);
+    final selectedTabId = ref.watch(selectedTabProvider);
+    final toolbarState = ref.watch(
+      toolbarVisibilityControllerProvider(selectedTabId),
+    );
 
-    // Toolbar is visible when: sheet is shown OR (not fullscreen AND app bar visible)
+    // Toolbar is visible when: sheet is shown OR (not fullscreen AND controller says visible)
-    // appBarVisible reflects both scroll-based auto-hide and swipe dismiss state
+    // The controller handles loading-start show internally via ref.listen on isLoading
+    final effectiveAppBarVisible =
+        toolbarState == ToolbarVisibility.visible;
     final topToolbarVisible =
-        sheetDisplayed || (!tabInFullScreen && appBarVisible);
+        sheetDisplayed || (!tabInFullScreen && effectiveAppBarVisible);
     final bottomToolbarVisible =
-        sheetDisplayed || (!tabInFullScreen && appBarVisible);
+        sheetDisplayed || (!tabInFullScreen && effectiveAppBarVisible);
 
     // Calculate relative safe area for sheet max size
     final relativeSafeArea = MediaQuery.of(context).relativeSafeArea();
@@ -382,7 +367,6 @@ class BrowserScreen extends HookConsumerWidget {
     final pixelRatio = MediaQuery.of(context).devicePixelRatio;
 
     // Watch find-in-page visibility for the selected tab
-    final selectedTabId = ref.watch(selectedTabProvider);
     final findInPageVisible =
         selectedTabId != null &&
         ref.watch(
@@ -446,7 +430,8 @@ class BrowserScreen extends HookConsumerWidget {
     // Keep clipping state in sync with keyboard and auto-hide states.
     // While keyboard is visible, do not apply toolbar clipping.
     useEffect(() {
-      final targetClippingPx = autoHideTabBar && !keyboardVisible
+      final targetClippingPx =
+          autoHideTabBar && !keyboardVisible && !tabIsLoading
           ? desiredToolbarClippingPx.value
           : 0;
 
@@ -456,7 +441,7 @@ class BrowserScreen extends HookConsumerWidget {
       }
 
       return null;
-    }, [autoHideTabBar, keyboardVisible]);
+    }, [autoHideTabBar, keyboardVisible, tabIsLoading]);
 
     final animationProgressCallback = useCallback((
       double progress,
@@ -467,13 +452,15 @@ class BrowserScreen extends HookConsumerWidget {
       final clippingPx = -((1.0 - progress) * heightPx * pixelRatio).round();
       desiredToolbarClippingPx.value = clippingPx;
 
-      final targetClippingPx = keyboardVisible ? 0 : clippingPx;
+      final targetClippingPx = (keyboardVisible || tabIsLoading)
+          ? 0
+          : clippingPx;
 
       if (targetClippingPx != lastClippingPx.value) {
         lastClippingPx.value = targetClippingPx;
         unawaited(viewportService.setVerticalClipping(targetClippingPx));
       }
-    }, [keyboardVisible, pixelRatio]);
+    }, [keyboardVisible, pixelRatio, tabIsLoading]);
 
     // Theme with dynamic snackbar margin to position above bottom toolbar
     final themeData = Theme.of(context).copyWith(
@@ -522,7 +509,6 @@ class BrowserScreen extends HookConsumerWidget {
                 bottom: browserBottomOffset,
                 child: _Browser(
                   overlayController: overlayController,
-                  displayAppBar: displayAppBar,
                   tabInFullScreen: tabInFullScreen,
                   pointerMoveEventSink: pointerMoveEventsController.sink,
                   sheetDisplayed: sheetDisplayed,
@@ -558,7 +544,6 @@ class BrowserScreen extends HookConsumerWidget {
                       : null,
                   child: _TabBar(
                     tabBarPosition: TabBarPosition.bottom,
-                    displayAppBar: displayAppBar,
                     showMainToolbar: tabBarPosition == TabBarPosition.bottom,
                     showContextualToolbar: showContextualToolbar,
                     showQuickTabSwitcherBar: showQuickTabSwitcherBar,
@@ -583,7 +568,6 @@ class BrowserScreen extends HookConsumerWidget {
                     child: _TabBar(
                       tabBarPosition: TabBarPosition.top,
                       showMainToolbar: true,
-                      displayAppBar: displayAppBar,
                       showContextualToolbar: showContextualToolbar,
                       showQuickTabSwitcherBar: showQuickTabSwitcherBar,
                       pointerMoveEvents: pointerMoveEventsController.stream,
@@ -729,7 +713,6 @@ class _Browser extends HookConsumerWidget {
   Duration get _backButtonPressTimeout => const Duration(seconds: 2);
 
   final OverlayPortalController overlayController;
-  final ValueNotifier<bool> displayAppBar;
   final StreamSink<Offset> pointerMoveEventSink;
   final bool tabInFullScreen;
   final bool sheetDisplayed;
@@ -737,7 +720,6 @@ class _Browser extends HookConsumerWidget {
 
   const _Browser({
     required this.overlayController,
-    required this.displayAppBar,
     required this.tabInFullScreen,
     required this.pointerMoveEventSink,
     required this.sheetDisplayed,
@@ -822,9 +804,10 @@ class _Browser extends HookConsumerWidget {
                 }
 
                 //Make sure app bar is visible
-                if (!ref.read(tabBarDismissableControllerProvider)) {
+                final tabId = ref.read(selectedTabProvider);
-                  displayAppBar.value = true;
+                ref
-                }
+                    .read(toolbarVisibilityControllerProvider(tabId).notifier)
+                    .show();
 
                 if (tabState?.isLoading == true) {
                   lastBackButtonPress.value = null;

app/lib/features/geckoview/features/browser/presentation/widgets/browser_modules/bottom_app_bar.dart

@@ -32,12 +32,13 @@ import 'package:weblibre/core/routing/routes.dart';
 import 'package:weblibre/features/geckoview/domain/controllers/bottom_sheet.dart';
 import 'package:weblibre/features/geckoview/domain/entities/states/readerable.dart';
 import 'package:weblibre/features/geckoview/domain/entities/states/tab.dart';
+import 'package:weblibre/features/geckoview/domain/providers.dart';
 import 'package:weblibre/features/geckoview/domain/providers/selected_tab.dart';
 import 'package:weblibre/features/geckoview/domain/providers/tab_state.dart';
 import 'package:weblibre/features/geckoview/domain/repositories/tab.dart';
 import 'package:weblibre/features/geckoview/features/browser/domain/entities/sheet.dart';
 import 'package:weblibre/features/geckoview/features/browser/domain/providers.dart';
-import 'package:weblibre/features/geckoview/features/browser/presentation/controllers/tab_bar_dismissable.dart';
+import 'package:weblibre/features/geckoview/features/browser/presentation/controllers/toolbar_visibility.dart';
 import 'package:weblibre/features/geckoview/features/browser/presentation/widgets/browser_modules/app_bar_title.dart';
 import 'package:weblibre/features/geckoview/features/browser/presentation/widgets/extension_shortcut_menu.dart';
 import 'package:weblibre/features/geckoview/features/browser/presentation/widgets/menu_item_buttons.dart';
@@ -59,6 +60,7 @@ import 'package:weblibre/presentation/icons/weblibre_icons.dart';
 import 'package:weblibre/presentation/widgets/safe_raw_image.dart';
 import 'package:weblibre/presentation/widgets/selectable_chips.dart';
 import 'package:weblibre/presentation/widgets/url_icon.dart';
+import 'package:weblibre/utils/ui_helper.dart';
 
 class BrowserTopAppBar extends HookConsumerWidget {
   final bool showMainToolbar;
@@ -68,7 +70,8 @@ class BrowserTopAppBar extends HookConsumerWidget {
   late final BrowserTabBar _tabBar;
   late final _size = Size.fromHeight(_tabBar.getToolbarHeight());
 
-  BrowserTopAppBar({super.key, 
+  BrowserTopAppBar({
+    super.key,
     required this.showMainToolbar,
     required this.showContextualToolbar,
     required this.showQuickTabSwitcherBar,
@@ -103,7 +106,8 @@ class BrowserBottomAppBar extends HookConsumerWidget {
   late final BrowserTabBar _tabBar;
   late final _size = Size.fromHeight(_tabBar.getToolbarHeight());
 
-  BrowserBottomAppBar({super.key, 
+  BrowserBottomAppBar({
+    super.key,
     required this.showMainToolbar,
     required this.displayedSheet,
     required this.showContextualToolbar,
@@ -148,7 +152,8 @@ class BrowserTabBar extends HookConsumerWidget {
   final bool showMainToolbarNavigationButton;
   final bool showMainToolbarTabActionButton;
 
-  const BrowserTabBar({super.key, 
+  const BrowserTabBar({
+    super.key,
     required this.showMainToolbar,
     required this.displayedSheet,
     required this.showContextualToolbar,
@@ -270,8 +275,23 @@ class BrowserTabBar extends HookConsumerWidget {
             !distance.dy.isNegative && distance.dy.abs() > dismissThreshold,
         };
         if (shouldDismiss && ref.read(bottomSheetControllerProvider) == null) {
-          unawaited(HapticFeedback.lightImpact());
+          final viewportService = ref.read(viewportServiceProvider);
-          ref.read(tabBarDismissableControllerProvider.notifier).dismiss();
+          if (viewportService.isBrowserHandlingScrollEnabled) {
+            unawaited(HapticFeedback.lightImpact());
+            ref
+                .read(
+                  toolbarVisibilityControllerProvider(selectedTabId).notifier,
+                )
+                .dismiss();
+          } else if (context.mounted) {
+            showDismissOverrideMessage(context, () {
+              ref
+                  .read(
+                    toolbarVisibilityControllerProvider(selectedTabId).notifier,
+                  )
+                  .dismiss();
+            });
+          }
         }
       },
       child: Column(

app/lib/features/geckoview/features/browser/presentation/widgets/browser_modules/browser_fab.dart

@@ -21,8 +21,9 @@ import 'package:flutter/material.dart';
 import 'package:flutter_material_design_icons/flutter_material_design_icons.dart';
 import 'package:hooks_riverpod/hooks_riverpod.dart';
 import 'package:weblibre/features/geckoview/domain/entities/states/readerable.dart';
+import 'package:weblibre/features/geckoview/domain/providers/selected_tab.dart';
 import 'package:weblibre/features/geckoview/domain/providers/tab_state.dart';
-import 'package:weblibre/features/geckoview/features/browser/presentation/controllers/tab_bar_dismissable.dart';
+import 'package:weblibre/features/geckoview/features/browser/presentation/controllers/toolbar_visibility.dart';
 import 'package:weblibre/features/geckoview/features/readerview/domain/providers/readerable.dart';
 
 class BrowserFab extends HookConsumerWidget {
@@ -30,7 +31,10 @@ class BrowserFab extends HookConsumerWidget {
 
   @override
   Widget build(BuildContext context, WidgetRef ref) {
-    final tabBarDismissed = ref.watch(tabBarDismissableControllerProvider);
+    final selectedTabId = ref.watch(selectedTabProvider);
+    final toolbarState = ref.watch(
+      toolbarVisibilityControllerProvider(selectedTabId),
+    );
 
     final appearanceButtonVisible = ref.watch(
       appearanceButtonVisibilityProvider.select(
@@ -54,12 +58,16 @@ class BrowserFab extends HookConsumerWidget {
         },
         child: const Icon(MdiIcons.formatFont),
       );
-    } else if (tabBarDismissed) {
+    } else if (toolbarState == ToolbarVisibility.dismissed) {
       child = FloatingActionButton(
         key: const ValueKey('dock_fab'),
         heroTag: 'dock_fab',
         onPressed: () {
-          ref.read(tabBarDismissableControllerProvider.notifier).show();
+          ref
+              .read(
+                toolbarVisibilityControllerProvider(selectedTabId).notifier,
+              )
+              .forceShow();
         },
         child: const Icon(MdiIcons.dockBottom),
       );

app/lib/features/user/domain/repositories/profile.g.dart

@@ -33,7 +33,7 @@ final class ProfileRepositoryProvider
   ProfileRepository create() => ProfileRepository();
 }
 
-String _$profileRepositoryHash() => r'c17702af1e59727ab3fec26e9ca659048e92c8bb';
+String _$profileRepositoryHash() => r'b770e7406e1602f808cc8076c1eda67b4fce6b2d';
 
 abstract class _$ProfileRepository extends $AsyncNotifier<List<Profile>> {
   FutureOr<List<Profile>> build();

app/lib/utils/ui_helper.dart

@@ -192,3 +192,19 @@ void showTabUndoClose(
 
   ScaffoldMessenger.of(context).showSnackBar(snackBar);
 }
+
+void showDismissOverrideMessage(
+  BuildContext context,
+  VoidCallback onDismiss, {
+  Duration duration = const Duration(seconds: 4),
+}) {
+  ScaffoldMessenger.of(context).clearSnackBars();
+
+  final snackBar = _createFloatingSnackBar(
+    content: const Text('Hiding disabled by site'),
+    action: SnackBarAction(label: 'Dismiss', onPressed: onDismiss),
+    duration: duration,
+  );
+
+  ScaffoldMessenger.of(context).showSnackBar(snackBar);
+}

packages/flutter_mozilla_components/android/src/main/kotlin/eu/weblibre/flutter_mozilla_components/BaseBrowserFragment.kt

@@ -26,6 +26,7 @@ import eu.weblibre.flutter_mozilla_components.addons.WebExtensionActionPopupActi
 import eu.weblibre.flutter_mozilla_components.addons.WebExtensionPromptFeature
 import eu.weblibre.flutter_mozilla_components.databinding.FragmentBrowserBinding
 import eu.weblibre.flutter_mozilla_components.ext.getPreferenceKey
+import eu.weblibre.flutter_mozilla_components.feature.BrowserHandlingScrollFeature
 import eu.weblibre.flutter_mozilla_components.feature.KeyboardVisibilityFeature
 import eu.weblibre.flutter_mozilla_components.feature.ReadabilityExtractFeature
 import eu.weblibre.flutter_mozilla_components.feature.WebExtensionToolbarFeature
@@ -97,6 +98,9 @@ abstract class BaseBrowserFragment : Fragment(), UserInteractionHandler, Activit
     // Keyboard visibility detection feature
     private var keyboardVisibilityFeature: KeyboardVisibilityFeature? = null
 
+    // Browser scroll-handling detection feature
+    private var browserHandlingScrollFeature: BrowserHandlingScrollFeature? = null
+
     // Registers a photo picker activity launcher in single-select mode.
     private val singleMediaPicker =
         AndroidPhotoPicker.singleMediaPicker(
@@ -500,6 +504,10 @@ abstract class BaseBrowserFragment : Fragment(), UserInteractionHandler, Activit
                 keyboardVisibilityFeature = KeyboardVisibilityFeature(viewportEvents).also {
                     it.start(binding.root)
                 }
+
+                browserHandlingScrollFeature = BrowserHandlingScrollFeature(viewportEvents).also {
+                    it.start()
+                }
             }
 
             onEngineSetupComplete()
@@ -614,6 +622,10 @@ abstract class BaseBrowserFragment : Fragment(), UserInteractionHandler, Activit
         keyboardVisibilityFeature?.stop()
         keyboardVisibilityFeature = null
 
+        // Stop browser scroll-handling detection
+        browserHandlingScrollFeature?.stop()
+        browserHandlingScrollFeature = null
+
         GlobalComponents.onPullToRefreshEnabledChanged = null
         val engineView = fragmentEngineView
         engineView?.setActivityContext(null)

packages/flutter_mozilla_components/android/src/main/kotlin/eu/weblibre/flutter_mozilla_components/api/GeckoTabsApiImpl.kt

@@ -216,7 +216,8 @@ class GeckoTabsApiImpl : GeckoTabsApi {
                             progress = tab.content.progress.toLong(),
                             isPrivate = tab.content.private,
                             isFullScreen = tab.content.fullScreen,
-                            isLoading = tab.content.loading
+                            isLoading = tab.content.loading,
+                            showToolbarAsExpanded = tab.content.showToolbarAsExpanded,
                         )
                     ) { }
                 }

packages/flutter_mozilla_components/android/src/main/kotlin/eu/weblibre/flutter_mozilla_components/components/Events.kt

@@ -30,6 +30,7 @@ import kotlinx.coroutines.flow.distinctUntilChanged
 import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.mapNotNull
 import mozilla.components.browser.state.action.BrowserAction
+import mozilla.components.browser.state.action.ContentAction
 import mozilla.components.browser.state.selector.selectedTab
 import mozilla.components.browser.state.state.BrowserState
 import mozilla.components.feature.addons.logger
@@ -188,7 +189,8 @@ class Events(
                         it.content.private,
                         it.content.fullScreen,
                         it.content.progress,
-                        it.content.loading
+                        it.content.loading,
+                        it.content.showToolbarAsExpanded,
                     )
                 }
                 .debounce(15)
@@ -204,9 +206,19 @@ class Events(
                             progress = tab.content.progress.toLong(),
                             isPrivate = tab.content.private,
                             isFullScreen = tab.content.fullScreen,
-                            isLoading = tab.content.loading
+                            isLoading = tab.content.loading,
+                            showToolbarAsExpanded = tab.content.showToolbarAsExpanded,
                         )
                     ) { _ -> }
+
+                    // Reset showToolbarAsExpanded after forwarding to Flutter,
+                    // mirroring Fenix ToolbarBehaviorController behavior.
+                    // This ensures subsequent expand events trigger a new state change.
+                    if (tab.content.showToolbarAsExpanded) {
+                        stateFlow.dispatch(
+                            ContentAction.UpdateExpandedToolbarStateAction(tab.id, false)
+                        )
+                    }
                 }
         }
 

packages/flutter_mozilla_components/android/src/main/kotlin/eu/weblibre/flutter_mozilla_components/feature/BrowserHandlingScrollFeature.kt

@@ -0,0 +1,124 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+package eu.weblibre.flutter_mozilla_components.feature
+
+import android.view.MotionEvent
+import android.view.View
+import android.view.ViewGroup
+import eu.weblibre.flutter_mozilla_components.GlobalComponents
+import eu.weblibre.flutter_mozilla_components.ext.EventSequence
+import eu.weblibre.flutter_mozilla_components.pigeons.GeckoViewportEvents
+import org.mozilla.gecko.util.ThreadUtils.runOnUiThread
+
+/**
+ * Feature that reports whether GeckoView is currently handling scroll input.
+ *
+ * Checks InputResultDetail while active and only emits on state changes.
+ */
+class BrowserHandlingScrollFeature(
+    private val flutterEvents: GeckoViewportEvents,
+) {
+    private var running = false
+    private var touchSessionActive = false
+    private var lastValue: Boolean? = null
+    private var touchListener: View.OnTouchListener? = null
+    private var touchTargetView: View? = null
+
+    fun start() {
+        if (running) return
+        running = true
+        touchSessionActive = false
+        lastValue = null
+        attachTouchListenerIfPossible()
+    }
+
+    fun stop() {
+        if (!running) return
+        running = false
+        touchSessionActive = false
+        detachTouchListenerIfPossible()
+        lastValue = null
+    }
+
+    private fun attachTouchListenerIfPossible() {
+        val engineViewRoot = GlobalComponents.components?.mainBrowserEngineView?.asView()
+        if (engineViewRoot == null) return
+
+        if (touchListener != null) return
+
+        val targetView = resolveTouchTargetView(engineViewRoot)
+
+        touchListener = View.OnTouchListener { _, event ->
+            if (!running) return@OnTouchListener false
+
+            when (event.actionMasked) {
+                MotionEvent.ACTION_DOWN -> {
+                    touchSessionActive = true
+                    emitIfChanged()
+                }
+
+                MotionEvent.ACTION_MOVE -> {
+                    if (touchSessionActive) {
+                        emitIfChanged()
+                    }
+                }
+
+                MotionEvent.ACTION_UP,
+                MotionEvent.ACTION_CANCEL -> {
+                    touchSessionActive = false
+                }
+            }
+
+            // Never consume touch; GeckoView must keep handling it.
+            false
+        }
+
+        targetView.setOnTouchListener(touchListener)
+        touchTargetView = targetView
+    }
+
+    private fun detachTouchListenerIfPossible() {
+        if (touchTargetView != null && touchListener != null) {
+            touchTargetView?.setOnTouchListener(null)
+        }
+        touchListener = null
+        touchTargetView = null
+    }
+
+    private fun resolveTouchTargetView(root: View): View {
+        if (root !is ViewGroup) return root
+
+        // GeckoEngineView wraps the actual NestedGeckoView as its first child.
+        if (root.childCount > 0) {
+            return root.getChildAt(0)
+        }
+
+        return root
+    }
+
+    private fun emitIfChanged() {
+        val isHandling = try {
+            val engineView = GlobalComponents.components?.mainBrowserEngineView
+            if (engineView == null) {
+                false
+            } else {
+                val detail = engineView.getInputResultDetail()
+                detail.canScrollToTop() || detail.canScrollToBottom()
+            }
+        } catch (_: Throwable) {
+            false
+        }
+
+        if (lastValue == isHandling) return
+        lastValue = isHandling
+
+        val sequence = EventSequence.next()
+        runOnUiThread {
+            flutterEvents.onBrowserHandlingScrollChanged(sequence, isHandling) { }
+        }
+    }
+}

packages/flutter_mozilla_components/android/src/main/kotlin/eu/weblibre/flutter_mozilla_components/pigeons/Gecko.g.kt

@@ -1597,7 +1597,8 @@ data class TabContentState (
   val progress: Long,
   val isPrivate: Boolean,
   val isFullScreen: Boolean,
-  val isLoading: Boolean
+  val isLoading: Boolean,
+  val showToolbarAsExpanded: Boolean
 )
  {
   companion object {
@@ -1611,7 +1612,8 @@ data class TabContentState (
       val isPrivate = pigeonVar_list[6] as Boolean
       val isFullScreen = pigeonVar_list[7] as Boolean
       val isLoading = pigeonVar_list[8] as Boolean
-      return TabContentState(id, parentId, contextId, url, title, progress, isPrivate, isFullScreen, isLoading)
+      val showToolbarAsExpanded = pigeonVar_list[9] as Boolean
+      return TabContentState(id, parentId, contextId, url, title, progress, isPrivate, isFullScreen, isLoading, showToolbarAsExpanded)
     }
   }
   fun toList(): List<Any?> {
@@ -1625,6 +1627,7 @@ data class TabContentState (
       isPrivate,
       isFullScreen,
       isLoading,
+      showToolbarAsExpanded,
     )
   }
   override fun equals(other: Any?): Boolean {
@@ -6919,6 +6922,31 @@ class GeckoViewportEvents(private val binaryMessenger: BinaryMessenger, private
       } 
     }
   }
+  /**
+   * Called when GeckoView scroll-handling eligibility changes.
+   *
+   * [sequence] Event sequence number for ordering.
+   * [isHandling] True when browser content can consume scrolling for
+   * dynamic toolbar behavior. False when content is not scrollable or
+   * the page consumed touch input.
+   */
+  fun onBrowserHandlingScrollChanged(sequenceArg: Long, isHandlingArg: Boolean, callback: (Result<Unit>) -> Unit)
+{
+    val separatedMessageChannelSuffix = if (messageChannelSuffix.isNotEmpty()) ".$messageChannelSuffix" else ""
+    val channelName = "dev.flutter.pigeon.flutter_mozilla_components.GeckoViewportEvents.onBrowserHandlingScrollChanged$separatedMessageChannelSuffix"
+    val channel = BasicMessageChannel<Any?>(binaryMessenger, channelName, codec)
+    channel.send(listOf(sequenceArg, isHandlingArg)) {
+      if (it is List<*>) {
+        if (it.size > 1) {
+          callback(Result.failure(FlutterError(it[0] as String, it[1] as String, it[2] as String?)))
+        } else {
+          callback(Result.success(Unit))
+        }
+      } else {
+        callback(Result.failure(GeckoPigeonUtils.createConnectionError(channelName)))
+      } 
+    }
+  }
 }
 /** Generated interface from Pigeon that represents a handler of messages from Flutter. */
 interface GeckoBookmarksApi {

packages/flutter_mozilla_components/lib/src/domain/services/gecko_viewport.dart

@@ -30,6 +30,7 @@ class GeckoViewportService extends GeckoViewportEvents {
     isVisible: false,
     isAnimating: false,
   ));
+  final _browserHandlingScrollSubject = BehaviorSubject<bool>.seeded(false);
 
   /// Stream of keyboard visibility changes.
   ///
@@ -46,6 +47,17 @@ class GeckoViewportService extends GeckoViewportEvents {
   /// Whether the keyboard is currently visible.
   bool get isKeyboardVisible => _keyboardSubject.value.isVisible;
 
+  /// Stream of browser scroll-handling eligibility.
+  ///
+  /// Emits true when GeckoView reports that browser content can handle
+  /// scrolling for dynamic toolbar behavior.
+  ValueStream<bool> get browserHandlingScrollEvents =>
+      _browserHandlingScrollSubject.stream;
+
+  /// Current browser scroll-handling eligibility.
+  bool get isBrowserHandlingScrollEnabled =>
+      _browserHandlingScrollSubject.value;
+
   /// Creates a new viewport service.
   ///
   /// Call [setUp] to register the event handlers after construction.
@@ -113,8 +125,14 @@ class GeckoViewportService extends GeckoViewportEvents {
     ));
   }
 
+  @override
+  void onBrowserHandlingScrollChanged(int sequence, bool isHandling) {
+    _browserHandlingScrollSubject.addWhenMoreRecent(sequence, null, isHandling);
+  }
+
   /// Disposes the service and closes all streams.
   Future<void> dispose() async {
     await _keyboardSubject.close();
+    await _browserHandlingScrollSubject.close();
   }
 }

packages/flutter_mozilla_components/lib/src/pigeons/gecko.g.dart

@@ -1735,6 +1735,7 @@ class TabContentState {
     required this.isPrivate,
     required this.isFullScreen,
     required this.isLoading,
+    required this.showToolbarAsExpanded,
   });
 
   String id;
@@ -1755,6 +1756,8 @@ class TabContentState {
 
   bool isLoading;
 
+  bool showToolbarAsExpanded;
+
   List<Object?> _toList() {
     return <Object?>[
       id,
@@ -1766,6 +1769,7 @@ class TabContentState {
       isPrivate,
       isFullScreen,
       isLoading,
+      showToolbarAsExpanded,
     ];
   }
 
@@ -1784,6 +1788,7 @@ class TabContentState {
       isPrivate: result[6]! as bool,
       isFullScreen: result[7]! as bool,
       isLoading: result[8]! as bool,
+      showToolbarAsExpanded: result[9]! as bool,
     );
   }
 
@@ -8133,6 +8138,14 @@ abstract class GeckoViewportEvents {
   /// [isAnimating] Whether the keyboard is currently animating.
   void onKeyboardVisibilityChanged(int sequence, int heightPx, bool isVisible, bool isAnimating);
 
+  /// Called when GeckoView scroll-handling eligibility changes.
+  ///
+  /// [sequence] Event sequence number for ordering.
+  /// [isHandling] True when browser content can consume scrolling for
+  /// dynamic toolbar behavior. False when content is not scrollable or
+  /// the page consumed touch input.
+  void onBrowserHandlingScrollChanged(int sequence, bool isHandling);
+
   static void setUp(GeckoViewportEvents? api, {BinaryMessenger? binaryMessenger, String messageChannelSuffix = '',}) {
     messageChannelSuffix = messageChannelSuffix.isNotEmpty ? '.$messageChannelSuffix' : '';
     {
@@ -8169,6 +8182,34 @@ abstract class GeckoViewportEvents {
         });
       }
     }
+    {
+      final pigeonVar_channel = BasicMessageChannel<Object?>(
+          'dev.flutter.pigeon.flutter_mozilla_components.GeckoViewportEvents.onBrowserHandlingScrollChanged$messageChannelSuffix', pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (api == null) {
+        pigeonVar_channel.setMessageHandler(null);
+      } else {
+        pigeonVar_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+          'Argument for dev.flutter.pigeon.flutter_mozilla_components.GeckoViewportEvents.onBrowserHandlingScrollChanged was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final int? arg_sequence = (args[0] as int?);
+          assert(arg_sequence != null,
+              'Argument for dev.flutter.pigeon.flutter_mozilla_components.GeckoViewportEvents.onBrowserHandlingScrollChanged was null, expected non-null int.');
+          final bool? arg_isHandling = (args[1] as bool?);
+          assert(arg_isHandling != null,
+              'Argument for dev.flutter.pigeon.flutter_mozilla_components.GeckoViewportEvents.onBrowserHandlingScrollChanged was null, expected non-null bool.');
+          try {
+            api.onBrowserHandlingScrollChanged(arg_sequence!, arg_isHandling!);
+            return wrapResponse(empty: true);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          }          catch (e) {
+            return wrapResponse(error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
   }
 }
 

packages/flutter_mozilla_components/pigeons/gecko.dart

@@ -517,6 +517,7 @@ class TabContentState {
   final bool isPrivate;
   final bool isFullScreen;
   final bool isLoading;
+  final bool showToolbarAsExpanded;
 
   TabContentState(
     this.id,
@@ -528,6 +529,7 @@ class TabContentState {
     this.isPrivate,
     this.isFullScreen,
     this.isLoading,
+    this.showToolbarAsExpanded,
   );
 }
 
@@ -1746,6 +1748,14 @@ abstract class GeckoViewportEvents {
     bool isVisible,
     bool isAnimating,
   );
+
+  /// Called when GeckoView scroll-handling eligibility changes.
+  ///
+  /// [sequence] Event sequence number for ordering.
+  /// [isHandling] True when browser content can consume scrolling for
+  /// dynamic toolbar behavior. False when content is not scrollable or
+  /// the page consumed touch input.
+  void onBrowserHandlingScrollChanged(int sequence, bool isHandling);
 }
 
 // =============================================================================