respect disableAnimations flag

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

@@ -76,8 +76,10 @@ class _AnimatedToolbar extends HookWidget {
 
   @override
   Widget build(BuildContext context) {
+    final disableAnimations = MediaQuery.disableAnimationsOf(context);
+
     final controller = useAnimationController(
-      duration: _kAnimationDuration,
+      duration: disableAnimations ? Duration.zero : _kAnimationDuration,
       initialValue: visible ? 1.0 : 0.0,
     );
 

app/lib/features/geckoview/features/browser/presentation/widgets/browser_menu_sheet.dart

@@ -618,10 +618,7 @@ class _PinTopSiteTile extends HookConsumerWidget {
           } else {
             await ref
                 .read(topSiteRepositoryProvider.notifier)
-                .addPinnedSite(
-                  title: tabState.titleOrAuthority,
-                  url: url,
-                );
+                .addPinnedSite(title: tabState.titleOrAuthority, url: url);
             if (context.mounted) {
               ui_helper.showInfoMessage(context, 'Pinned to Top Sites');
             }
@@ -1932,19 +1929,21 @@ class _SyncTile extends HookConsumerWidget {
     );
     final isSyncing = syncStarted || syncInfo?.syncing == true;
 
+    final disableAnimations = MediaQuery.disableAnimationsOf(context);
+
     final controller = useAnimationController(
-      duration: const Duration(seconds: 2),
+      duration: disableAnimations ? Duration.zero : const Duration(seconds: 2),
     );
 
     useEffect(() {
-      if (isSyncing) {
+      if (isSyncing && !disableAnimations) {
         unawaited(controller.repeat());
       } else {
         controller.stop();
         controller.reset();
       }
       return null;
-    }, [isSyncing]);
+    }, [isSyncing, disableAnimations]);
 
     return ListTile(
       leading: RotationTransition(

app/lib/features/geckoview/features/browser/presentation/widgets/draggable_scrollable_header.dart

@@ -74,6 +74,11 @@ class _DraggableScrollableHeaderState extends State<DraggableScrollableHeader>
     double targetSize, {
     Duration? customDuration,
   }) async {
+    if (MediaQuery.disableAnimationsOf(context)) {
+      widget.controller.jumpTo(targetSize);
+      return;
+    }
+
     if (customDuration != null) {
       _animationController.duration = customDuration;
     } else {

app/lib/features/sync/presentation/screens/sync_settings.dart

@@ -53,19 +53,21 @@ class SyncSettingsScreen extends HookConsumerWidget {
       return 'Last synced: $formattedDate';
     }, [syncInfo, isSyncing]);
 
+    final disableAnimations = MediaQuery.disableAnimationsOf(context);
+
     final syncController = useAnimationController(
-      duration: const Duration(seconds: 2),
+      duration: disableAnimations ? Duration.zero : const Duration(seconds: 2),
     );
 
     useEffect(() {
-      if (isSyncing) {
+      if (isSyncing && !disableAnimations) {
         unawaited(syncController.repeat());
       } else {
         syncController.stop();
         syncController.reset();
       }
       return null;
-    }, [isSyncing]);
+    }, [isSyncing, disableAnimations]);
 
     return Scaffold(
       appBar: AppBar(title: const Text('Firefox Sync')),

app/lib/main.dart

@@ -81,6 +81,31 @@ bool _hasBrokenSurfaceContainerColors(ColorScheme scheme) {
       scheme.surfaceContainerHighest == scheme.surface;
 }
 
+class _NoAnimationPageTransitionsBuilder extends PageTransitionsBuilder {
+  const _NoAnimationPageTransitionsBuilder();
+
+  @override
+  Widget buildTransitions<T>(
+    PageRoute<T> route,
+    BuildContext context,
+    Animation<double> animation,
+    Animation<double> secondaryAnimation,
+    Widget child,
+  ) {
+    return child;
+  }
+}
+
+const _noAnimationPageTransitionsTheme = PageTransitionsTheme(
+  builders: {
+    TargetPlatform.android: _NoAnimationPageTransitionsBuilder(),
+    TargetPlatform.iOS: _NoAnimationPageTransitionsBuilder(),
+    TargetPlatform.linux: _NoAnimationPageTransitionsBuilder(),
+    TargetPlatform.macOS: _NoAnimationPageTransitionsBuilder(),
+    TargetPlatform.windows: _NoAnimationPageTransitionsBuilder(),
+  },
+);
+
 class _MainWidget extends HookConsumerWidget {
   const _MainWidget();
 
@@ -257,11 +282,17 @@ class _MainWidget extends HookConsumerWidget {
           theme: ThemeData(
             useMaterial3: true,
             colorScheme: lightColorScheme,
+            pageTransitionsTheme: disableAnimations
+                ? _noAnimationPageTransitionsTheme
+                : null,
             extensions: const <ThemeExtension<dynamic>>[AppColors.light],
           ),
           darkTheme: ThemeData(
             useMaterial3: true,
             colorScheme: darkColorScheme,
+            pageTransitionsTheme: disableAnimations
+                ? _noAnimationPageTransitionsTheme
+                : null,
             extensions: const <ThemeExtension<dynamic>>[AppColors.dark],
           ),
           themeMode: themeMode,

app/lib/presentation/main_app.dart

@@ -55,6 +55,9 @@ class MainApp extends HookConsumerWidget {
             theme: theme,
             darkTheme: darkTheme,
             themeMode: themeMode,
+            themeAnimationStyle: disableAnimations
+                ? AnimationStyle.noAnimation
+                : null,
             builder: (context, child) {
               return _AppMediaQueryOverrides(
                 uiScaleFactor: uiScaleFactor,
@@ -85,6 +88,9 @@ class MainApp extends HookConsumerWidget {
           theme: theme,
           darkTheme: darkTheme,
           themeMode: themeMode,
+          themeAnimationStyle: disableAnimations
+              ? AnimationStyle.noAnimation
+              : null,
           routerConfig: router.value,
           builder: (context, child) {
             return _AppMediaQueryOverrides(
@@ -103,6 +109,9 @@ class MainApp extends HookConsumerWidget {
           theme: theme,
           darkTheme: darkTheme,
           themeMode: themeMode,
+          themeAnimationStyle: disableAnimations
+              ? AnimationStyle.noAnimation
+              : null,
           builder: (context, child) {
             return _AppMediaQueryOverrides(
               uiScaleFactor: uiScaleFactor,

app/lib/presentation/widgets/animate_gradient_shader.dart

@@ -120,12 +120,24 @@ class _AnimateGradientShaderState extends State<AnimateGradientShader>
   List<Color> primaryColors = [];
   List<Color> secondaryColors = [];
 
+  bool _disableAnimations = false;
+
   @override
   void initState() {
     _initialize();
     super.initState();
   }
 
+  @override
+  void didChangeDependencies() {
+    super.didChangeDependencies();
+    final disableAnimations = MediaQuery.disableAnimationsOf(context);
+    if (disableAnimations != _disableAnimations) {
+      _disableAnimations = disableAnimations;
+      _setAnimations();
+    }
+  }
+
   @override
   void didUpdateWidget(AnimateGradientShader oldWidget) {
     _initialize();
@@ -222,10 +234,15 @@ class _AnimateGradientShaderState extends State<AnimateGradientShader>
   void _setAnimations() {
     _controller?.dispose();
     _controller =
-        (widget.controller ??
-              AnimationController(vsync: this, duration: widget.duration))
-          // ignore: discarded_futures
-          ..repeat(reverse: widget.reverse);
+        widget.controller ??
+        AnimationController(vsync: this, duration: widget.duration);
+
+    if (_disableAnimations) {
+      _controller!.value = 0;
+    } else {
+      // ignore: discarded_futures
+      _controller!.repeat(reverse: widget.reverse);
+    }
 
     _animation = CurvedAnimation(parent: _controller!, curve: Curves.easeInOut);
   }

app/lib/presentation/widgets/animated_indexed_stack.dart

@@ -129,12 +129,30 @@ class _AnimatedIndexedStackState extends State<AnimatedIndexedStack>
   /// The entry which is currently at the top of the stack.
   _ChildEntry? _currentEntry;
 
+  bool _disableAnimations = false;
+
+  Duration get _effectiveDuration =>
+      _disableAnimations ? Duration.zero : widget.duration;
+
   @override
   void initState() {
     super.initState();
     _updateEntriesList();
   }
 
+  @override
+  void didChangeDependencies() {
+    super.didChangeDependencies();
+    final disableAnimations = MediaQuery.disableAnimationsOf(context);
+    if (disableAnimations != _disableAnimations) {
+      _disableAnimations = disableAnimations;
+      for (final entry in _entries) {
+        entry.primaryController.duration = _effectiveDuration;
+        entry.secondaryController.duration = _effectiveDuration;
+      }
+    }
+  }
+
   @override
   void didUpdateWidget(AnimatedIndexedStack oldWidget) {
     super.didUpdateWidget(oldWidget);
@@ -207,8 +225,8 @@ class _AnimatedIndexedStackState extends State<AnimatedIndexedStack>
         // If we find an existing entry, we update its child widget and reuse it.
         // This ensures it continues to use the same global key and animation controllers.
         existingEntry.child = child;
-        existingEntry.primaryController.duration = widget.duration;
-        existingEntry.secondaryController.duration = widget.duration;
+        existingEntry.primaryController.duration = _effectiveDuration;
+        existingEntry.secondaryController.duration = _effectiveDuration;
         entry = existingEntry;
       } else {
         entry = _newEntry(child);
@@ -299,11 +317,11 @@ class _AnimatedIndexedStackState extends State<AnimatedIndexedStack>
     key: GlobalKey(),
     child: child,
     primaryController: AnimationController(
-      duration: widget.duration,
+      duration: _effectiveDuration,
       vsync: this,
     ),
     secondaryController: AnimationController(
-      duration: widget.duration,
+      duration: _effectiveDuration,
       vsync: this,
     ),
   );