Remove deprecated Scaffold SnackBar API (#98549)

packages/flutter/lib/src/material/scaffold.dart

@@ -2017,195 +2017,8 @@ class ScaffoldState extends State<Scaffold> with TickerProviderStateMixin, Resto
 
   // Used for both the snackbar and material banner APIs
   ScaffoldMessengerState? _scaffoldMessenger;
-  bool? _accessibleNavigation;
 
   // SNACKBAR API
-  final Queue<ScaffoldFeatureController<SnackBar, SnackBarClosedReason>> _snackBars = Queue<ScaffoldFeatureController<SnackBar, SnackBarClosedReason>>();
-  AnimationController? _snackBarController;
-  Timer? _snackBarTimer;
-
-  /// [ScaffoldMessengerState.showSnackBar] shows a [SnackBar] at the bottom of
-  /// the scaffold. This method should not be used, and will be deprecated in
-  /// the near future..
-  ///
-  /// A scaffold can show at most one snack bar at a time. If this function is
-  /// called while another snack bar is already visible, the given snack bar
-  /// will be added to a queue and displayed after the earlier snack bars have
-  /// closed.
-  ///
-  /// To control how long a [SnackBar] remains visible, use [SnackBar.duration].
-  ///
-  /// To remove the [SnackBar] with an exit animation, use
-  /// [ScaffoldMessengerState.hideCurrentSnackBar] or call
-  /// [ScaffoldFeatureController.close] on the returned [ScaffoldFeatureController].
-  /// To remove a [SnackBar] suddenly (without an animation), use
-  /// [ScaffoldMessengerState.removeCurrentSnackBar].
-  ///
-  /// See [ScaffoldMessenger.of] for information about how to obtain the
-  /// [ScaffoldMessengerState].
-  ///
-  /// {@tool dartpad}
-  /// Here is an example of showing a [SnackBar] when the user presses a button.
-  ///
-  /// ** See code in examples/api/lib/material/scaffold/scaffold_state.show_snack_bar.0.dart **
-  /// {@end-tool}
-  ///
-  /// See also:
-  ///
-  ///   * [ScaffoldMessenger], this should be used instead to manage [SnackBar]s.
-  @Deprecated(
-    'Use ScaffoldMessenger.showSnackBar. '
-    'This feature was deprecated after v1.23.0-14.0.pre.',
-  )
-  ScaffoldFeatureController<SnackBar, SnackBarClosedReason> showSnackBar(SnackBar snackbar) {
-    _snackBarController ??= SnackBar.createAnimationController(vsync: this)
-      ..addStatusListener(_handleSnackBarStatusChange);
-    if (_snackBars.isEmpty) {
-      assert(_snackBarController!.isDismissed);
-      _snackBarController!.forward();
-    }
-    late ScaffoldFeatureController<SnackBar, SnackBarClosedReason> controller;
-    controller = ScaffoldFeatureController<SnackBar, SnackBarClosedReason>._(
-      // We provide a fallback key so that if back-to-back snackbars happen to
-      // match in structure, material ink splashes and highlights don't survive
-      // from one to the next.
-      snackbar.withAnimation(_snackBarController!, fallbackKey: UniqueKey()),
-      Completer<SnackBarClosedReason>(),
-      () {
-        assert(_snackBars.first == controller);
-        hideCurrentSnackBar();
-      },
-      null, // SnackBar doesn't use a builder function so setState() wouldn't rebuild it
-    );
-    setState(() {
-      _snackBars.addLast(controller);
-    });
-    return controller;
-  }
-
-  void _handleSnackBarStatusChange(AnimationStatus status) {
-    switch (status) {
-      case AnimationStatus.dismissed:
-        assert(_snackBars.isNotEmpty);
-        setState(() {
-          _snackBars.removeFirst();
-        });
-        if (_snackBars.isNotEmpty)
-          _snackBarController!.forward();
-        break;
-      case AnimationStatus.completed:
-        setState(() {
-          assert(_snackBarTimer == null);
-          // build will create a new timer if necessary to dismiss the snack bar
-        });
-        break;
-      case AnimationStatus.forward:
-      case AnimationStatus.reverse:
-        break;
-    }
-  }
-
-  /// [ScaffoldMessengerState.removeCurrentSnackBar] removes the current
-  /// [SnackBar] (if any) immediately. This method should not be used, and will
-  /// be deprecated in the near future.
-  ///
-  /// The removed snack bar does not run its normal exit animation. If there are
-  /// any queued snack bars, they begin their entrance animation immediately.
-  ///
-  /// See also:
-  ///
-  ///   * [ScaffoldMessenger], this should be used instead to manage [SnackBar]s.
-  @Deprecated(
-    'Use ScaffoldMessenger.removeCurrentSnackBar. '
-    'This feature was deprecated after v1.23.0-14.0.pre.',
-  )
-  void removeCurrentSnackBar({ SnackBarClosedReason reason = SnackBarClosedReason.remove }) {
-    assert(reason != null);
-
-    // SnackBars and SnackBarActions can call to hide and remove themselves, but
-    // they are not aware of who presented them, the Scaffold or the
-    // ScaffoldMessenger. As such, when the SnackBar classes call upon Scaffold
-    // to remove (the current default), we should re-direct to the
-    // ScaffoldMessenger here if that is where the SnackBar originated from.
-    if (_messengerSnackBar != null) {
-      // ScaffoldMessenger is presenting SnackBars.
-      assert(debugCheckHasScaffoldMessenger(context));
-      assert(
-        _scaffoldMessenger != null,
-        'A SnackBar was shown by the ScaffoldMessenger, but has been called upon '
-        'to be removed from a Scaffold that is not registered with a '
-        'ScaffoldMessenger, this can happen if a Scaffold has been rebuilt '
-        'without an ancestor ScaffoldMessenger.',
-      );
-      _scaffoldMessenger!.removeCurrentSnackBar(reason: reason);
-      return;
-    }
-
-    if (_snackBars.isEmpty)
-      return;
-    final Completer<SnackBarClosedReason> completer = _snackBars.first._completer;
-    if (!completer.isCompleted)
-      completer.complete(reason);
-    _snackBarTimer?.cancel();
-    _snackBarTimer = null;
-    _snackBarController!.value = 0.0;
-  }
-
-  /// [ScaffoldMessengerState.hideCurrentSnackBar] removes the current
-  /// [SnackBar] by running its normal exit animation. This method should not be
-  /// used, and will be deprecated in the near future.
-  ///
-  /// The closed completer is called after the animation is complete.
-  ///
-  /// See also:
-  ///
-  ///   * [ScaffoldMessenger], this should be used instead to manage [SnackBar]s.
-  @Deprecated(
-    'Use ScaffoldMessenger.hideCurrentSnackBar. '
-    'This feature was deprecated after v1.23.0-14.0.pre.',
-  )
-  void hideCurrentSnackBar({ SnackBarClosedReason reason = SnackBarClosedReason.hide }) {
-    assert(reason != null);
-
-    // SnackBars and SnackBarActions can call to hide and remove themselves, but
-    // they are not aware of who presented them, the Scaffold or the
-    // ScaffoldMessenger. As such, when the SnackBar classes call upon Scaffold
-    // to remove (the current default), we should re-direct to the
-    // ScaffoldMessenger here if that is where the SnackBar originated from.
-    if (_messengerSnackBar != null) {
-      // ScaffoldMessenger is presenting SnackBars.
-      assert(debugCheckHasScaffoldMessenger(context));
-      assert(
-        _scaffoldMessenger != null,
-        'A SnackBar was shown by the ScaffoldMessenger, but has been called upon '
-        'to be removed from a Scaffold that is not registered with a '
-        'ScaffoldMessenger, this can happen if a Scaffold has been rebuilt '
-        'without an ancestor ScaffoldMessenger.',
-      );
-      _scaffoldMessenger!.hideCurrentSnackBar(reason: reason);
-      return;
-    }
-
-    if (_snackBars.isEmpty || _snackBarController!.status == AnimationStatus.dismissed)
-      return;
-    final MediaQueryData mediaQuery = MediaQuery.of(context);
-    final Completer<SnackBarClosedReason> completer = _snackBars.first._completer;
-    if (mediaQuery.accessibleNavigation) {
-      _snackBarController!.value = 0.0;
-      completer.complete(reason);
-    } else {
-      _snackBarController!.reverse().then<void>((void value) {
-        assert(mounted);
-        if (!completer.isCompleted)
-          completer.complete(reason);
-      });
-    }
-    _snackBarTimer?.cancel();
-    _snackBarTimer = null;
-  }
-
-  // The _messengerSnackBar represents the current SnackBar being managed by
-  // the ScaffoldMessenger, instead of the Scaffold.
   ScaffoldFeatureController<SnackBar, SnackBarClosedReason>? _messengerSnackBar;
 
   // This is used to update the _messengerSnackBar by the ScaffoldMessenger.
@@ -2672,31 +2485,12 @@ class ScaffoldState extends State<Scaffold> with TickerProviderStateMixin, Resto
     _scaffoldMessenger = currentScaffoldMessenger;
     _scaffoldMessenger?._register(this);
 
-    // TODO(Piinks): Remove old SnackBar API after migrating ScaffoldMessenger
-    final MediaQueryData mediaQuery = MediaQuery.of(context);
-    // If we transition from accessible navigation to non-accessible navigation
-    // and there is a SnackBar that would have timed out that has already
-    // completed its timer, dismiss that SnackBar. If the timer hasn't finished
-    // yet, let it timeout as normal.
-    if ((_accessibleNavigation ?? false)
-      && !mediaQuery.accessibleNavigation
-      && _snackBarTimer != null
-      && !_snackBarTimer!.isActive) {
-      hideCurrentSnackBar(reason: SnackBarClosedReason.timeout);
-    }
-    _accessibleNavigation = mediaQuery.accessibleNavigation;
-
     _maybeBuildPersistentBottomSheet();
     super.didChangeDependencies();
   }
 
   @override
   void dispose() {
-    // TODO(Piinks): Remove old SnackBar API after migrating ScaffoldMessenger
-    _snackBarController?.dispose();
-    _snackBarTimer?.cancel();
-    _snackBarTimer = null;
-
     _geometryNotifier.dispose();
     _floatingActionButtonMoveController.dispose();
     _floatingActionButtonVisibilityController.dispose();
@@ -2817,31 +2611,6 @@ class ScaffoldState extends State<Scaffold> with TickerProviderStateMixin, Resto
     final ThemeData themeData = Theme.of(context);
     final TextDirection textDirection = Directionality.of(context);
 
-    // TODO(Piinks): Remove old SnackBar API after migrating ScaffoldMessenger
-    _accessibleNavigation = mediaQuery.accessibleNavigation;
-    if (_snackBars.isNotEmpty) {
-      final ModalRoute<dynamic>? route = ModalRoute.of(context);
-      if (route == null || route.isCurrent) {
-        if (_snackBarController!.isCompleted && _snackBarTimer == null) {
-          final SnackBar snackBar = _snackBars.first._widget;
-          _snackBarTimer = Timer(snackBar.duration, () {
-            assert(
-              _snackBarController!.status == AnimationStatus.forward ||
-                _snackBarController!.status == AnimationStatus.completed,
-            );
-            // Look up MediaQuery again in case the setting changed.
-            final MediaQueryData mediaQuery = MediaQuery.of(context);
-            if (mediaQuery.accessibleNavigation && snackBar.action != null)
-              return;
-            hideCurrentSnackBar(reason: SnackBarClosedReason.timeout);
-          });
-        }
-      } else {
-        _snackBarTimer?.cancel();
-        _snackBarTimer = null;
-      }
-    }
-
     final List<LayoutId> children = <LayoutId>[];
     _addIfNonNull(
       children,
@@ -2895,15 +2664,6 @@ class ScaffoldState extends State<Scaffold> with TickerProviderStateMixin, Resto
 
     bool isSnackBarFloating = false;
     double? snackBarWidth;
-    // We should only be using one API for SnackBars. Currently, we can use the
-    // Scaffold, which creates a SnackBar queue (_snackBars), or the
-    // ScaffoldMessenger, which sends a SnackBar to descendant Scaffolds.
-    // (_messengerSnackBar).
-    assert(
-      _snackBars.isEmpty || _messengerSnackBar == null,
-      'Only one API should be used to manage SnackBars. The ScaffoldMessenger is '
-      'the preferred API instead of the Scaffold methods.',
-    );
 
     if (_currentBottomSheet != null || _dismissedBottomSheets.isNotEmpty) {
       final Widget stack = Stack(
@@ -2944,27 +2704,6 @@ class ScaffoldState extends State<Scaffold> with TickerProviderStateMixin, Resto
       );
     }
 
-    // SnackBar set by Scaffold
-    // TODO(Piinks): Remove old SnackBar API after migrating ScaffoldMessenger
-    if (_snackBars.isNotEmpty) {
-      final SnackBarBehavior snackBarBehavior = _snackBars.first._widget.behavior
-        ?? themeData.snackBarTheme.behavior
-        ?? SnackBarBehavior.fixed;
-      isSnackBarFloating = snackBarBehavior == SnackBarBehavior.floating;
-      snackBarWidth = _snackBars.first._widget.width;
-
-      _addIfNonNull(
-        children,
-        _snackBars.first._widget,
-        _ScaffoldSlot.snackBar,
-        removeLeftPadding: false,
-        removeTopPadding: true,
-        removeRightPadding: false,
-        removeBottomPadding: widget.bottomNavigationBar != null || widget.persistentFooterButtons != null,
-        maintainBottomViewPadding: !_resizeToAvoidBottomInset,
-      );
-    }
-
     bool extendBodyBehindMaterialBanner = false;
     // MaterialBanner set by ScaffoldMessenger
     if (_messengerMaterialBanner != null) {

packages/flutter/lib/src/material/snack_bar.dart

@@ -122,7 +122,7 @@ class _SnackBarActionState extends State<SnackBarAction> {
       _haveTriggeredAction = true;
     });
     widget.onPressed();
-    Scaffold.of(context).hideCurrentSnackBar(reason: SnackBarClosedReason.action);
+    ScaffoldMessenger.of(context).hideCurrentSnackBar(reason: SnackBarClosedReason.action);
   }
 
   @override
@@ -583,14 +583,14 @@ class _SnackBarState extends State<SnackBar> {
       container: true,
       liveRegion: true,
       onDismiss: () {
-        Scaffold.of(context).removeCurrentSnackBar(reason: SnackBarClosedReason.dismiss);
+        ScaffoldMessenger.of(context).removeCurrentSnackBar(reason: SnackBarClosedReason.dismiss);
       },
       child: Dismissible(
         key: const Key('dismissible'),
         direction: widget.dismissDirection,
         resizeDuration: null,
         onDismissed: (DismissDirection direction) {
-          Scaffold.of(context).removeCurrentSnackBar(reason: SnackBarClosedReason.swipe);
+          ScaffoldMessenger.of(context).removeCurrentSnackBar(reason: SnackBarClosedReason.swipe);
         },
         child: snackBar,
       ),

packages/flutter/test/material/debug_test.dart

@@ -263,8 +263,10 @@ void main() {
         ),
       ),
     ));
-    // The Scaffold should assert we still have an ancestor ScaffoldMessenger in
+    // Tap SnackBarAction to dismiss.
-    // order to dismiss the SnackBar from the ScaffoldMessenger.
+    // The SnackBarAction should assert we still have an ancestor
+    // ScaffoldMessenger in order to dismiss the SnackBar from the
+    // Scaffold.
     await tester.tap(find.text('Test'));
     FlutterError.onError = oldHandler;
 
@@ -286,11 +288,67 @@ void main() {
     expect(error.toStringDeep(), equalsIgnoringHashCodes(
       'FlutterError\n'
       '   No ScaffoldMessenger widget found.\n'
-      '   Scaffold widgets require a ScaffoldMessenger widget ancestor.\n'
+      '   SnackBarAction widgets require a ScaffoldMessenger widget\n'
+      '   ancestor.\n'
       '   The specific widget that could not find a ScaffoldMessenger\n'
       '   ancestor was:\n'
-      '     Scaffold-[LabeledGlobalKey<ScaffoldState>#00829]\n'
+      '     SnackBarAction\n'
       '   The ancestors of this widget were:\n'
+      '     TextButtonTheme\n'
+      '     Padding\n'
+      '     Row\n'
+      '     Padding\n'
+      '     MediaQuery\n'
+      '     Padding\n'
+      '     SafeArea\n'
+      '     FadeTransition\n'
+      '     IconTheme\n'
+      '     IconTheme\n'
+      '     _InheritedCupertinoTheme\n'
+      '     CupertinoTheme\n'
+      '     _InheritedTheme\n'
+      '     Theme\n'
+      '     DefaultTextStyle\n'
+      '     AnimatedDefaultTextStyle\n'
+      '     _InkFeatures-[GlobalKey#00000 ink renderer]\n'
+      '     NotificationListener<LayoutChangedNotification>\n'
+      '     PhysicalModel\n'
+      '     AnimatedPhysicalModel\n'
+      '     Material\n'
+      '     FractionalTranslation\n'
+      '     SlideTransition\n'
+      '     Listener\n'
+      '     _GestureSemantics\n'
+      '     RawGestureDetector\n'
+      '     GestureDetector\n'
+      "     Dismissible-[<'dismissible'>]\n"
+      '     Semantics\n'
+      '     Align\n'
+      '     AnimatedBuilder\n'
+      '     ClipRect\n'
+      '     KeyedSubtree-[GlobalKey#00000]\n'
+      '     _EffectiveTickerMode\n'
+      '     TickerMode\n'
+      '     Offstage\n'
+      '     SizedBox\n'
+      '     Hero\n'
+      '     SnackBar-[#00000]\n'
+      '     MediaQuery\n'
+      '     LayoutId-[<_ScaffoldSlot.snackBar>]\n'
+      '     CustomMultiChildLayout\n'
+      '     AnimatedBuilder\n'
+      '     DefaultTextStyle\n'
+      '     AnimatedDefaultTextStyle\n'
+      '     _InkFeatures-[GlobalKey#00000 ink renderer]\n'
+      '     NotificationListener<LayoutChangedNotification>\n'
+      '     PhysicalModel\n'
+      '     AnimatedPhysicalModel\n'
+      '     Material\n'
+      '     _ScrollMetricsNotificationObserverScope\n'
+      '     NotificationListener<ScrollMetricsNotification>\n'
+      '     ScrollMetricsNotificationObserver\n'
+      '     _ScaffoldScope\n'
+      '     Scaffold-[LabeledGlobalKey<ScaffoldState>#00000]\n'
       '     MediaQuery\n'
       '     Directionality\n'
       '     [root]\n'

packages/flutter/test/material/snack_bar_test.dart

@@ -8,58 +8,12 @@
 
 import 'dart:ui';
 
-import 'package:flutter/foundation.dart' show FlutterExceptionHandler;
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 void main() {
   testWidgets('SnackBar control test', (WidgetTester tester) async {
-    const String helloSnackBar = 'Hello SnackBar';
-    const Key tapTarget = Key('tap-target');
-    await tester.pumpWidget(MaterialApp(
-      home: Scaffold(
-        body: Builder(
-          builder: (BuildContext context) {
-            return GestureDetector(
-              key: tapTarget,
-              onTap: () {
-                Scaffold.of(context).showSnackBar(const SnackBar(
-                  content: Text(helloSnackBar),
-                  duration: Duration(seconds: 2),
-                ));
-              },
-              behavior: HitTestBehavior.opaque,
-              child: const SizedBox(
-                height: 100.0,
-                width: 100.0,
-              ),
-            );
-          },
-        ),
-      ),
-    ));
-    expect(find.text(helloSnackBar), findsNothing);
-    await tester.tap(find.byKey(tapTarget));
-    expect(find.text(helloSnackBar), findsNothing);
-    await tester.pump(); // schedule animation
-    expect(find.text(helloSnackBar), findsOneWidget);
-    await tester.pump(); // begin animation
-    expect(find.text(helloSnackBar), findsOneWidget);
-    await tester.pump(const Duration(milliseconds: 750)); // 0.75s // animation last frame; two second timer starts here
-    expect(find.text(helloSnackBar), findsOneWidget);
-    await tester.pump(const Duration(milliseconds: 750)); // 1.50s
-    expect(find.text(helloSnackBar), findsOneWidget);
-    await tester.pump(const Duration(milliseconds: 750)); // 2.25s
-    expect(find.text(helloSnackBar), findsOneWidget);
-    await tester.pump(const Duration(milliseconds: 750)); // 3.00s // timer triggers to dismiss snackbar, reverse animation is scheduled
-    await tester.pump(); // begin animation
-    expect(find.text(helloSnackBar), findsOneWidget); // frame 0 of dismiss animation
-    await tester.pump(const Duration(milliseconds: 750)); // 3.75s // last frame of animation, snackbar removed from build
-    expect(find.text(helloSnackBar), findsNothing);
-  });
-
-  testWidgets('SnackBar control test - ScaffoldMessenger', (WidgetTester tester) async {
     const String helloSnackBar = 'Hello SnackBar';
     const Key tapTarget = Key('tap-target');
     await tester.pumpWidget(MaterialApp(
@@ -105,81 +59,6 @@ void main() {
   });
 
   testWidgets('SnackBar twice test', (WidgetTester tester) async {
-    int snackBarCount = 0;
-    const Key tapTarget = Key('tap-target');
-    await tester.pumpWidget(MaterialApp(
-      home: Scaffold(
-        body: Builder(
-          builder: (BuildContext context) {
-            return GestureDetector(
-              key: tapTarget,
-              onTap: () {
-                snackBarCount += 1;
-                Scaffold.of(context).showSnackBar(SnackBar(
-                  content: Text('bar$snackBarCount'),
-                  duration: const Duration(seconds: 2),
-                ));
-              },
-              behavior: HitTestBehavior.opaque,
-              child: const SizedBox(
-                height: 100.0,
-                width: 100.0,
-              ),
-            );
-          },
-        ),
-      ),
-    ));
-    expect(find.text('bar1'), findsNothing);
-    expect(find.text('bar2'), findsNothing);
-    await tester.tap(find.byKey(tapTarget)); // queue bar1
-    await tester.tap(find.byKey(tapTarget)); // queue bar2
-    expect(find.text('bar1'), findsNothing);
-    expect(find.text('bar2'), findsNothing);
-    await tester.pump(); // schedule animation for bar1
-    expect(find.text('bar1'), findsOneWidget);
-    expect(find.text('bar2'), findsNothing);
-    await tester.pump(); // begin animation
-    expect(find.text('bar1'), findsOneWidget);
-    expect(find.text('bar2'), findsNothing);
-    await tester.pump(const Duration(milliseconds: 750)); // 0.75s // animation last frame; two second timer starts here
-    expect(find.text('bar1'), findsOneWidget);
-    expect(find.text('bar2'), findsNothing);
-    await tester.pump(const Duration(milliseconds: 750)); // 1.50s
-    expect(find.text('bar1'), findsOneWidget);
-    expect(find.text('bar2'), findsNothing);
-    await tester.pump(const Duration(milliseconds: 750)); // 2.25s
-    expect(find.text('bar1'), findsOneWidget);
-    expect(find.text('bar2'), findsNothing);
-    await tester.pump(const Duration(milliseconds: 750)); // 3.00s // timer triggers to dismiss snackbar, reverse animation is scheduled
-    await tester.pump(); // begin animation
-    expect(find.text('bar1'), findsOneWidget);
-    expect(find.text('bar2'), findsNothing);
-    await tester.pump(const Duration(milliseconds: 750)); // 3.75s // last frame of animation, snackbar removed from build, new snack bar put in its place
-    expect(find.text('bar1'), findsNothing);
-    expect(find.text('bar2'), findsOneWidget);
-    await tester.pump(); // begin animation
-    expect(find.text('bar1'), findsNothing);
-    expect(find.text('bar2'), findsOneWidget);
-    await tester.pump(const Duration(milliseconds: 750)); // 4.50s // animation last frame; two second timer starts here
-    expect(find.text('bar1'), findsNothing);
-    expect(find.text('bar2'), findsOneWidget);
-    await tester.pump(const Duration(milliseconds: 750)); // 5.25s
-    expect(find.text('bar1'), findsNothing);
-    expect(find.text('bar2'), findsOneWidget);
-    await tester.pump(const Duration(milliseconds: 750)); // 6.00s
-    expect(find.text('bar1'), findsNothing);
-    expect(find.text('bar2'), findsOneWidget);
-    await tester.pump(const Duration(milliseconds: 750)); // 6.75s // timer triggers to dismiss snackbar, reverse animation is scheduled
-    await tester.pump(); // begin animation
-    expect(find.text('bar1'), findsNothing);
-    expect(find.text('bar2'), findsOneWidget);
-    await tester.pump(const Duration(milliseconds: 750)); // 7.50s // last frame of animation, snackbar removed from build, new snack bar put in its place
-    expect(find.text('bar1'), findsNothing);
-    expect(find.text('bar2'), findsNothing);
-  });
-
-  testWidgets('SnackBar twice test - ScaffoldMessenger', (WidgetTester tester) async {
     int snackBarCount = 0;
     const Key tapTarget = Key('tap-target');
     await tester.pumpWidget(MaterialApp(
@@ -255,92 +134,6 @@ void main() {
   });
 
   testWidgets('SnackBar cancel test', (WidgetTester tester) async {
-    int snackBarCount = 0;
-    const Key tapTarget = Key('tap-target');
-    late int time;
-    late ScaffoldFeatureController<SnackBar, SnackBarClosedReason> lastController;
-    await tester.pumpWidget(MaterialApp(
-      home: Scaffold(
-        body: Builder(
-          builder: (BuildContext context) {
-            return GestureDetector(
-              key: tapTarget,
-              onTap: () {
-                snackBarCount += 1;
-                lastController = Scaffold.of(context).showSnackBar(SnackBar(
-                  content: Text('bar$snackBarCount'),
-                  duration: Duration(seconds: time),
-                ));
-              },
-              behavior: HitTestBehavior.opaque,
-              child: const SizedBox(
-                height: 100.0,
-                width: 100.0,
-              ),
-            );
-          },
-        ),
-      ),
-    ));
-    expect(find.text('bar1'), findsNothing);
-    expect(find.text('bar2'), findsNothing);
-    time = 1000;
-    await tester.tap(find.byKey(tapTarget)); // queue bar1
-    final ScaffoldFeatureController<SnackBar, SnackBarClosedReason> firstController = lastController;
-    time = 2;
-    await tester.tap(find.byKey(tapTarget)); // queue bar2
-    expect(find.text('bar1'), findsNothing);
-    expect(find.text('bar2'), findsNothing);
-    await tester.pump(); // schedule animation for bar1
-    expect(find.text('bar1'), findsOneWidget);
-    expect(find.text('bar2'), findsNothing);
-    await tester.pump(); // begin animation
-    expect(find.text('bar1'), findsOneWidget);
-    expect(find.text('bar2'), findsNothing);
-    await tester.pump(const Duration(milliseconds: 750)); // 0.75s // animation last frame; two second timer starts here
-    expect(find.text('bar1'), findsOneWidget);
-    expect(find.text('bar2'), findsNothing);
-    await tester.pump(const Duration(milliseconds: 750)); // 1.50s
-    expect(find.text('bar1'), findsOneWidget);
-    expect(find.text('bar2'), findsNothing);
-    await tester.pump(const Duration(milliseconds: 750)); // 2.25s
-    expect(find.text('bar1'), findsOneWidget);
-    expect(find.text('bar2'), findsNothing);
-    await tester.pump(const Duration(milliseconds: 10000)); // 12.25s
-    expect(find.text('bar1'), findsOneWidget);
-    expect(find.text('bar2'), findsNothing);
-
-    firstController.close(); // snackbar is manually dismissed
-
-    await tester.pump(const Duration(milliseconds: 750)); // 13.00s // reverse animation is scheduled
-    await tester.pump(); // begin animation
-    expect(find.text('bar1'), findsOneWidget);
-    expect(find.text('bar2'), findsNothing);
-    await tester.pump(const Duration(milliseconds: 750)); // 13.75s // last frame of animation, snackbar removed from build, new snack bar put in its place
-    expect(find.text('bar1'), findsNothing);
-    expect(find.text('bar2'), findsOneWidget);
-    await tester.pump(); // begin animation
-    expect(find.text('bar1'), findsNothing);
-    expect(find.text('bar2'), findsOneWidget);
-    await tester.pump(const Duration(milliseconds: 750)); // 14.50s // animation last frame; two second timer starts here
-    expect(find.text('bar1'), findsNothing);
-    expect(find.text('bar2'), findsOneWidget);
-    await tester.pump(const Duration(milliseconds: 750)); // 15.25s
-    expect(find.text('bar1'), findsNothing);
-    expect(find.text('bar2'), findsOneWidget);
-    await tester.pump(const Duration(milliseconds: 750)); // 16.00s
-    expect(find.text('bar1'), findsNothing);
-    expect(find.text('bar2'), findsOneWidget);
-    await tester.pump(const Duration(milliseconds: 750)); // 16.75s // timer triggers to dismiss snackbar, reverse animation is scheduled
-    await tester.pump(); // begin animation
-    expect(find.text('bar1'), findsNothing);
-    expect(find.text('bar2'), findsOneWidget);
-    await tester.pump(const Duration(milliseconds: 750)); // 17.50s // last frame of animation, snackbar removed from build, new snack bar put in its place
-    expect(find.text('bar1'), findsNothing);
-    expect(find.text('bar2'), findsNothing);
-  });
-
-  testWidgets('SnackBar cancel test - ScaffoldMessenger', (WidgetTester tester) async {
     int snackBarCount = 0;
     const Key tapTarget = Key('tap-target');
     late int time;
@@ -432,48 +225,6 @@ void main() {
     late double width;
     int snackBarCount = 0;
 
-    await tester.pumpWidget(MaterialApp(
-      home: Scaffold(
-        body: Builder(
-          builder: (BuildContext context) {
-            width = MediaQuery.of(context).size.width;
-
-            return GestureDetector(
-              key: tapTarget,
-              onTap: () {
-                snackBarCount += 1;
-                Scaffold.of(context).showSnackBar(SnackBar(
-                  content: Text('bar$snackBarCount'),
-                  duration: const Duration(seconds: 2),
-                  dismissDirection: dismissDirection,
-                ));
-              },
-              behavior: HitTestBehavior.opaque,
-              child: const SizedBox(
-                height: 100.0,
-                width: 100.0,
-              ),
-            );
-          },
-        ),
-      ),
-    ));
-
-    await _testSnackBarDismiss(
-      tester: tester,
-      tapTarget: tapTarget,
-      scaffoldWidth: width,
-      onDismissDirectionChange: (DismissDirection dir) => dismissDirection = dir,
-      onDragGestureChange: () => snackBarCount = 0,
-    );
-  });
-
-  testWidgets('SnackBar dismiss test - ScaffoldMessenger', (WidgetTester tester) async {
-    const Key tapTarget = Key('tap-target');
-    late DismissDirection dismissDirection;
-    late double width;
-    int snackBarCount = 0;
-
     await tester.pumpWidget(MaterialApp(
       home: Scaffold(
         body: Builder(
@@ -511,45 +262,6 @@ void main() {
   });
 
   testWidgets('SnackBar cannot be tapped twice', (WidgetTester tester) async {
-    int tapCount = 0;
-    await tester.pumpWidget(MaterialApp(
-      home: Scaffold(
-        body: Builder(
-          builder: (BuildContext context) {
-            return GestureDetector(
-              onTap: () {
-                Scaffold.of(context).showSnackBar(SnackBar(
-                  content: const Text('I am a snack bar.'),
-                  duration: const Duration(seconds: 2),
-                  action: SnackBarAction(
-                    label: 'ACTION',
-                    onPressed: () {
-                      ++tapCount;
-                    },
-                  ),
-                ));
-              },
-              child: const Text('X'),
-            );
-          },
-        ),
-      ),
-    ));
-    await tester.tap(find.text('X'));
-    await tester.pump(); // start animation
-    await tester.pump(const Duration(milliseconds: 750));
-
-    expect(tapCount, equals(0));
-    await tester.tap(find.text('ACTION'));
-    expect(tapCount, equals(1));
-    await tester.tap(find.text('ACTION'));
-    expect(tapCount, equals(1));
-    await tester.pump();
-    await tester.tap(find.text('ACTION'));
-    expect(tapCount, equals(1));
-  });
-
-  testWidgets('SnackBar cannot be tapped twice - ScaffoldMessenger', (WidgetTester tester) async {
     int tapCount = 0;
     await tester.pumpWidget(MaterialApp(
       home: Scaffold(
@@ -598,7 +310,7 @@ void main() {
             builder: (BuildContext context) {
               return GestureDetector(
                 onTap: () {
-                  Scaffold.of(context).showSnackBar(
+                  ScaffoldMessenger.of(context).showSnackBar(
                     SnackBar(
                       content: const Text('I am a snack bar.'),
                       duration: const Duration(seconds: 2),
@@ -640,7 +352,7 @@ void main() {
             builder: (BuildContext context) {
               return GestureDetector(
                 onTap: () {
-                  Scaffold.of(context).showSnackBar(
+                  ScaffoldMessenger.of(context).showSnackBar(
                     SnackBar(
                       content: const Text('I am a snack bar.'),
                       duration: const Duration(seconds: 2),
@@ -679,7 +391,7 @@ void main() {
             builder: (BuildContext context) {
               return GestureDetector(
                 onTap: () {
-                  Scaffold.of(context).showSnackBar(
+                  ScaffoldMessenger.of(context).showSnackBar(
                     SnackBar(
                       content: const Text('I am a snack bar.'),
                       duration: const Duration(seconds: 2),
@@ -809,7 +521,7 @@ void main() {
               themeBeforeSnackBar = Theme.of(context);
               return GestureDetector(
                 onTap: () {
-                  Scaffold.of(context).showSnackBar(
+                  ScaffoldMessenger.of(context).showSnackBar(
                     SnackBar(
                       content: Builder(
                         builder: (BuildContext context) {
@@ -853,7 +565,7 @@ void main() {
             builder: (BuildContext context) {
               return GestureDetector(
                 onTap: () {
-                  Scaffold.of(context).showSnackBar(
+                  ScaffoldMessenger.of(context).showSnackBar(
                     const SnackBar(
                       content: Text('I am a snack bar.'),
                       margin: EdgeInsets.all(padding),
@@ -885,53 +597,6 @@ void main() {
   });
 
   testWidgets('SnackbarBehavior.floating is positioned within safe area', (WidgetTester tester) async {
-    const double viewPadding = 50.0;
-    const double floatingSnackBarDefaultBottomMargin = 10.0;
-    await tester.pumpWidget(
-      MaterialApp(
-        home: MediaQuery(
-          data: const MediaQueryData(
-            // Simulate non-safe area.
-            viewPadding: EdgeInsets.only(bottom: viewPadding),
-          ),
-          child: Scaffold(
-            body: Builder(
-              builder: (BuildContext context) {
-                return GestureDetector(
-                  onTap: () {
-                    Scaffold.of(context).showSnackBar(
-                      const SnackBar(
-                        content: Text('I am a snack bar.'),
-                        behavior: SnackBarBehavior.floating,
-                      ),
-                    );
-                  },
-                  child: const Text('X'),
-                );
-              },
-            ),
-          ),
-        ),
-      ),
-    );
-
-    await tester.tap(find.text('X'));
-    await tester.pump(); // Start animation
-    await tester.pump(const Duration(milliseconds: 750));
-
-    final Finder materialFinder = find.descendant(
-      of: find.byType(SnackBar),
-      matching: find.byType(Material),
-    );
-    final Offset snackBarBottomLeft = tester.getBottomLeft(materialFinder);
-    expect(
-      snackBarBottomLeft.dy,
-      // Device height is 600.
-      600 - viewPadding - floatingSnackBarDefaultBottomMargin,
-    );
-  });
-
-  testWidgets('SnackbarBehavior.floating is positioned within safe area - ScaffoldMessenger', (WidgetTester tester) async {
     const double viewPadding = 50.0;
     const double floatingSnackBarDefaultBottomMargin = 10.0;
     await tester.pumpWidget(
@@ -1452,47 +1117,6 @@ void main() {
   testWidgets('accessible navigation behavior with action', (WidgetTester tester) async {
     final GlobalKey<ScaffoldState> scaffoldKey = GlobalKey<ScaffoldState>();
 
-    await tester.pumpWidget(MaterialApp(
-      home: MediaQuery(
-        data: const MediaQueryData(accessibleNavigation: true),
-        child: Scaffold(
-          key: scaffoldKey,
-          body: Builder(
-            builder: (BuildContext context) {
-              return GestureDetector(
-                onTap: () {
-                  Scaffold.of(context).showSnackBar(SnackBar(
-                    content: const Text('snack'),
-                    duration: const Duration(seconds: 1),
-                    action: SnackBarAction(
-                      label: 'ACTION',
-                      onPressed: () { },
-                    ),
-                  ));
-                },
-                child: const Text('X'),
-              );
-            },
-          ),
-        ),
-      ),
-    ));
-    await tester.tap(find.text('X'));
-    await tester.pump();
-    // Find action immediately
-    expect(find.text('ACTION'), findsOneWidget);
-    // Snackbar doesn't close
-    await tester.pump(const Duration(seconds: 10));
-    expect(find.text('ACTION'), findsOneWidget);
-    await tester.tap(find.text('ACTION'));
-    await tester.pump();
-    // Snackbar closes immediately
-    expect(find.text('ACTION'), findsNothing);
-  });
-
-  testWidgets('accessible navigation behavior with action - ScaffoldMessenger', (WidgetTester tester) async {
-    final GlobalKey<ScaffoldState> scaffoldKey = GlobalKey<ScaffoldState>();
-
     await tester.pumpWidget(MaterialApp(
       home: MediaQuery(
         data: const MediaQueryData(accessibleNavigation: true),
@@ -1537,47 +1161,6 @@ void main() {
     final SemanticsHandle handle = tester.ensureSemantics();
     final GlobalKey<ScaffoldState> scaffoldKey = GlobalKey<ScaffoldState>();
 
-    await tester.pumpWidget(MaterialApp(
-      home: MediaQuery(
-        data: const MediaQueryData(accessibleNavigation: true),
-        child: Scaffold(
-          key: scaffoldKey,
-          body: Builder(builder: (BuildContext context) {
-            return GestureDetector(
-              onTap: () {
-                Scaffold.of(context).showSnackBar(SnackBar(
-                  content: const Text('snack'),
-                  duration: const Duration(seconds: 1),
-                  action: SnackBarAction(
-                    label: 'ACTION',
-                    onPressed: () { },
-                  ),
-                ));
-              },
-              child: const Text('X'),
-            );
-          }),
-        ),
-      ),
-    ));
-    await tester.tap(find.text('X'));
-    await tester.pumpAndSettle();
-
-    expect(tester.getSemantics(find.text('snack')), matchesSemantics(
-      isLiveRegion: true,
-      hasDismissAction: true,
-      hasScrollDownAction: true,
-      hasScrollUpAction: true,
-      label: 'snack',
-      textDirection: TextDirection.ltr,
-    ));
-    handle.dispose();
-  });
-
-  testWidgets('contributes dismiss semantics - ScaffoldMessenger', (WidgetTester tester) async {
-    final SemanticsHandle handle = tester.ensureSemantics();
-    final GlobalKey<ScaffoldState> scaffoldKey = GlobalKey<ScaffoldState>();
-
     await tester.pumpWidget(MaterialApp(
       home: MediaQuery(
         data: const MediaQueryData(accessibleNavigation: true),
@@ -1666,54 +1249,6 @@ void main() {
   });
 
   testWidgets('SnackBar handles updates to accessibleNavigation', (WidgetTester tester) async {
-    Future<void> boilerplate({ required bool accessibleNavigation }) {
-      return tester.pumpWidget(MaterialApp(
-        home: MediaQuery(
-          data: MediaQueryData(accessibleNavigation: accessibleNavigation),
-          child: Scaffold(
-            body: Builder(
-              builder: (BuildContext context) {
-                return GestureDetector(
-                  onTap: () {
-                    Scaffold.of(context).showSnackBar(SnackBar(
-                      content: const Text('test'),
-                      action: SnackBarAction(label: 'foo', onPressed: () { }),
-                    ));
-                  },
-                  behavior: HitTestBehavior.opaque,
-                  child: const Text('X'),
-                );
-              },
-            ),
-          ),
-        ),
-      ));
-    }
-
-    await boilerplate(accessibleNavigation: false);
-    expect(find.text('test'), findsNothing);
-    await tester.tap(find.text('X'));
-    await tester.pump(); // schedule animation
-    expect(find.text('test'), findsOneWidget);
-    await tester.pump(); // begin animation
-    await tester.pump(const Duration(milliseconds: 4750)); // 4.75s
-    expect(find.text('test'), findsOneWidget);
-
-    // Enabled accessible navigation
-    await boilerplate(accessibleNavigation: true);
-
-    await tester.pump(const Duration(milliseconds: 4000)); // 8.75s
-    await tester.pump();
-    expect(find.text('test'), findsOneWidget);
-
-    // disable accessible navigation
-    await boilerplate(accessibleNavigation: false);
-    await tester.pumpAndSettle(const Duration(milliseconds: 5750));
-
-    expect(find.text('test'), findsNothing);
-  });
-
-  testWidgets('SnackBar handles updates to accessibleNavigation - ScaffoldMessenger', (WidgetTester tester) async {
     Future<void> boilerplate({ required bool accessibleNavigation }) {
       return tester.pumpWidget(MaterialApp(
         home: MediaQuery(
@@ -2127,7 +1662,7 @@ void main() {
                 builder: (BuildContext context) {
                     return GestureDetector(
                       onTap: () {
-                        Scaffold.of(context).showSnackBar(SnackBar(
+                        ScaffoldMessenger.of(context).showSnackBar(SnackBar(
                           content: const Text('Some content'),
                           behavior: SnackBarBehavior.fixed,
                           action: SnackBarAction(
@@ -2164,7 +1699,7 @@ void main() {
                 builder: (BuildContext context) {
                     return GestureDetector(
                       onTap: () {
-                        Scaffold.of(context).showSnackBar(SnackBar(
+                        ScaffoldMessenger.of(context).showSnackBar(SnackBar(
                           content: const Text('Some content'),
                           behavior: SnackBarBehavior.floating,
                           action: SnackBarAction(
@@ -2260,39 +1795,6 @@ void main() {
     expect(find.text(secondHeader), findsOneWidget);
   });
 
-  testWidgets('SnackBars cannot be used by the Scaffold and ScaffoldMessenger at the same time', (WidgetTester tester) async {
-    await tester.pumpWidget(const MaterialApp(
-      home: Scaffold(),
-    ));
-
-    final ScaffoldMessengerState scaffoldMessengerState = tester.state(find.byType(ScaffoldMessenger));
-    scaffoldMessengerState.showSnackBar(SnackBar(
-      content: const Text('ScaffoldMessenger'),
-      duration: const Duration(seconds: 2),
-      action: SnackBarAction(label: 'ACTION', onPressed: () {}),
-      behavior: SnackBarBehavior.floating,
-    ));
-    final ScaffoldState scaffoldState = tester.state(find.byType(Scaffold));
-    scaffoldState.showSnackBar(SnackBar(
-      content: const Text('Scaffold'),
-      duration: const Duration(seconds: 2),
-      action: SnackBarAction(label: 'ACTION', onPressed: () {}),
-      behavior: SnackBarBehavior.floating,
-    ));
-
-    final List<dynamic> exceptions = <dynamic>[];
-    final FlutterExceptionHandler? oldHandler = FlutterError.onError;
-    FlutterError.onError = (FlutterErrorDetails details) {
-      exceptions.add(details.exception);
-    };
-    await tester.pump();
-    FlutterError.onError = oldHandler;
-
-    expect(exceptions.length, 1);
-    final AssertionError error = exceptions.first as AssertionError;
-    expect(error.message, contains('Only one API should be used to manage SnackBars.'));
-  });
-
   testWidgets('SnackBars should be shown above the bottomSheet', (WidgetTester tester) async {
     await tester.pumpWidget(const MaterialApp(
       home: Scaffold(