Remove the FocusScopeNode in the navigator (#109702)

packages/flutter/lib/src/widgets/app.dart

@@ -13,6 +13,7 @@ import 'banner.dart';
 import 'basic.dart';
 import 'binding.dart';
 import 'default_text_editing_shortcuts.dart';
+import 'focus_scope.dart';
 import 'focus_traversal.dart';
 import 'framework.dart';
 import 'localizations.dart';
@@ -1625,19 +1626,23 @@ class _WidgetsAppState extends State<WidgetsApp> with WidgetsBindingObserver {
       );
     } else if (_usesNavigator) {
       assert(_navigator != null);
-      routing = Navigator(
-        restorationScopeId: 'nav',
-        key: _navigator,
-        initialRoute: _initialRouteName,
-        onGenerateRoute: _onGenerateRoute,
-        onGenerateInitialRoutes: widget.onGenerateInitialRoutes == null
-          ? Navigator.defaultGenerateInitialRoutes
-          : (NavigatorState navigator, String initialRouteName) {
-            return widget.onGenerateInitialRoutes!(initialRouteName);
-          },
-        onUnknownRoute: _onUnknownRoute,
-        observers: widget.navigatorObservers!,
-        reportsRouteUpdateToEngine: true,
+      routing = FocusScope(
+        debugLabel: 'Navigator Scope',
+        autofocus: true,
+        child: Navigator(
+          restorationScopeId: 'nav',
+          key: _navigator,
+          initialRoute: _initialRouteName,
+          onGenerateRoute: _onGenerateRoute,
+          onGenerateInitialRoutes: widget.onGenerateInitialRoutes == null
+            ? Navigator.defaultGenerateInitialRoutes
+            : (NavigatorState navigator, String initialRouteName) {
+              return widget.onGenerateInitialRoutes!(initialRouteName);
+            },
+          onUnknownRoute: _onUnknownRoute,
+          observers: widget.navigatorObservers!,
+          reportsRouteUpdateToEngine: true,
+        ),
       );
     } else if (_usesRouterWithConfig) {
       routing = Router<Object>.withConfig(

packages/flutter/lib/src/widgets/navigator.dart

@@ -17,6 +17,7 @@ import 'basic.dart';
 import 'binding.dart';
 import 'focus_manager.dart';
 import 'focus_scope.dart';
+import 'focus_traversal.dart';
 import 'framework.dart';
 import 'heroes.dart';
 import 'overlay.dart';
@@ -217,7 +218,7 @@ abstract class Route<T> {
   TickerFuture didPush() {
     return TickerFuture.complete()..then<void>((void _) {
       if (navigator?.widget.requestFocus ?? false) {
-        navigator!.focusScopeNode.requestFocus();
+        navigator!.focusNode.enclosingScope?.requestFocus();
       }
     });
   }
@@ -233,11 +234,11 @@ abstract class Route<T> {
   @mustCallSuper
   void didAdd() {
     if (navigator?.widget.requestFocus ?? false) {
-      // This TickerFuture serves two purposes. First, we want to make sure
-      // that animations triggered by other operations will finish before focusing the
-      // navigator. Second, navigator.focusScopeNode might acquire more focused
-      // children in Route.install asynchronously. This TickerFuture will wait for
-      // it to finish first.
+      // This TickerFuture serves two purposes. First, we want to make sure that
+      // animations triggered by other operations will finish before focusing
+      // the navigator. Second, navigator.focusNode might acquire more focused
+      // children in Route.install asynchronously. This TickerFuture will wait
+      // for it to finish first.
       //
       // The later case can be found when subclasses manage their own focus scopes.
       // For example, ModalRoute creates a focus scope in its overlay entries. The
@@ -255,7 +256,7 @@ abstract class Route<T> {
         // Since the reference to the navigator will be set to null after it is
         // disposed, we have to do a null-safe operation in case that happens
         // within the same frame when it is added.
-        navigator?.focusScopeNode.requestFocus();
+        navigator?.focusNode.enclosingScope?.requestFocus();
       });
     }
   }
@@ -3207,8 +3208,15 @@ class NavigatorState extends State<Navigator> with TickerProviderStateMixin, Res
   final Queue<_NavigatorObservation> _observedRouteAdditions = Queue<_NavigatorObservation>();
   final Queue<_NavigatorObservation> _observedRouteDeletions = Queue<_NavigatorObservation>();
 
-  /// The [FocusScopeNode] for the [FocusScope] that encloses the routes.
-  final FocusScopeNode focusScopeNode = FocusScopeNode(debugLabel: 'Navigator Scope');
+  /// The [FocusScopeNode] for the [FocusScope] that encloses the topmost navigator.
+  @Deprecated(
+    'Use focusNode.enclosingScope! instead. '
+    'This feature was deprecated after v3.1.0-0.0.pre.'
+  )
+  FocusScopeNode get focusScopeNode => focusNode.enclosingScope!;
+
+  /// The [FocusNode] for the [Focus] that encloses the routes.
+  final FocusNode focusNode = FocusNode(debugLabel: 'Navigator');
 
   bool _debugLocked = false; // used to prevent re-entrant calls to push, pop, and friends
 
@@ -3531,7 +3539,7 @@ class NavigatorState extends State<Navigator> with TickerProviderStateMixin, Res
       return true;
     }());
     _updateHeroController(null);
-    focusScopeNode.dispose();
+    focusNode.dispose();
     for (final _RouteEntry entry in _history) {
       entry.dispose();
     }
@@ -5226,14 +5234,18 @@ class NavigatorState extends State<Navigator> with TickerProviderStateMixin, Res
         onPointerCancel: _handlePointerUpOrCancel,
         child: AbsorbPointer(
           absorbing: false, // it's mutated directly by _cancelActivePointers above
-          child: FocusScope(
-            node: focusScopeNode,
-            autofocus: true,
-            child: UnmanagedRestorationScope(
-              bucket: bucket,
-              child: Overlay(
-                key: _overlayKey,
-                initialEntries: overlay == null ?  _allRouteOverlayEntries.toList(growable: false) : const <OverlayEntry>[],
+          child: FocusTraversalGroup(
+            child: Focus(
+              focusNode: focusNode,
+              autofocus: true,
+              skipTraversal: true,
+              includeSemantics: false,
+              child: UnmanagedRestorationScope(
+                bucket: bucket,
+                child: Overlay(
+                  key: _overlayKey,
+                  initialEntries: overlay == null ?  _allRouteOverlayEntries.toList(growable: false) : const <OverlayEntry>[],
+                ),
               ),
             ),
           ),

packages/flutter/lib/src/widgets/routes.dart

@@ -819,7 +819,7 @@ class _ModalScopeState<T> extends State<_ModalScope<T>> {
     ];
     _listenable = Listenable.merge(animations);
     if (widget.route.isCurrent && _shouldRequestFocus) {
-      widget.route.navigator!.focusScopeNode.setFirstFocus(focusScopeNode);
+      widget.route.navigator!.focusNode.enclosingScope?.setFirstFocus(focusScopeNode);
     }
   }
 
@@ -828,7 +828,7 @@ class _ModalScopeState<T> extends State<_ModalScope<T>> {
     super.didUpdateWidget(oldWidget);
     assert(widget.route == oldWidget.route);
     if (widget.route.isCurrent && _shouldRequestFocus) {
-      widget.route.navigator!.focusScopeNode.setFirstFocus(focusScopeNode);
+      widget.route.navigator!.focusNode.enclosingScope?.setFirstFocus(focusScopeNode);
     }
   }
 
@@ -863,7 +863,7 @@ class _ModalScopeState<T> extends State<_ModalScope<T>> {
   // and route.offstage.
   void _routeSetState(VoidCallback fn) {
     if (widget.route.isCurrent && !_shouldIgnoreFocusRequest && _shouldRequestFocus) {
-      widget.route.navigator!.focusScopeNode.setFirstFocus(focusScopeNode);
+      widget.route.navigator!.focusNode.enclosingScope?.setFirstFocus(focusScopeNode);
     }
     setState(fn);
   }
@@ -1213,7 +1213,7 @@ abstract class ModalRoute<T> extends TransitionRoute<T> with LocalHistoryRoute<T
   @override
   TickerFuture didPush() {
     if (_scopeKey.currentState != null && navigator!.widget.requestFocus) {
-      navigator!.focusScopeNode.setFirstFocus(_scopeKey.currentState!.focusScopeNode);
+      navigator!.focusNode.enclosingScope?.setFirstFocus(_scopeKey.currentState!.focusScopeNode);
     }
     return super.didPush();
   }
@@ -1221,7 +1221,7 @@ abstract class ModalRoute<T> extends TransitionRoute<T> with LocalHistoryRoute<T
   @override
   void didAdd() {
     if (_scopeKey.currentState != null && navigator!.widget.requestFocus) {
-      navigator!.focusScopeNode.setFirstFocus(_scopeKey.currentState!.focusScopeNode);
+      navigator!.focusNode.enclosingScope?.setFirstFocus(_scopeKey.currentState!.focusScopeNode);
     }
     super.didAdd();
   }

packages/flutter/test/material/app_builder_test.dart

@@ -17,7 +17,7 @@ void main() {
         log.add('build');
         expect(Theme.of(context).primaryColor, Colors.green);
         expect(Directionality.of(context), TextDirection.ltr);
-        expect(child, isA<Navigator>());
+        expect(child, isA<FocusScope>());
         return const Placeholder();
       },
     );

packages/flutter/test/material/debug_test.dart

@@ -156,12 +156,18 @@ void main() {
       '     Overlay-[LabeledGlobalKey<OverlayState>#00000]\n'
       '     UnmanagedRestorationScope\n'
       '     _FocusMarker\n'
-      '     Semantics\n'
-      '     FocusScope\n'
+      '     Focus\n'
+      '     _FocusMarker\n'
+      '     Focus\n'
+      '     _FocusTraversalGroupMarker\n'
+      '     FocusTraversalGroup\n'
       '     AbsorbPointer\n'
       '     Listener\n'
       '     HeroControllerScope\n'
       '     Navigator-[GlobalObjectKey<NavigatorState> _WidgetsAppState#00000]\n'
+      '     _FocusMarker\n'
+      '     Semantics\n'
+      '     FocusScope\n'
       '     DefaultSelectionStyle\n'
       '     IconTheme\n'
       '     IconTheme\n'

packages/flutter/test/material/dropdown_test.dart

@@ -1326,53 +1326,49 @@ void main() {
         TestSemantics.rootChild(
           children: <TestSemantics>[
             TestSemantics(
+              flags: <SemanticsFlag>[
+                SemanticsFlag.scopesRoute,
+                SemanticsFlag.namesRoute,
+              ],
+              label: 'Popup menu',
               children: <TestSemantics>[
                 TestSemantics(
-                  flags: <SemanticsFlag>[
-                    SemanticsFlag.scopesRoute,
-                    SemanticsFlag.namesRoute,
-                  ],
-                  label: 'Popup menu',
                   children: <TestSemantics>[
                     TestSemantics(
+                      flags: <SemanticsFlag>[
+                        SemanticsFlag.hasImplicitScrolling,
+                      ],
                       children: <TestSemantics>[
                         TestSemantics(
+                          label: 'one',
+                          textDirection: TextDirection.ltr,
                           flags: <SemanticsFlag>[
-                            SemanticsFlag.hasImplicitScrolling,
-                          ],
-                          children: <TestSemantics>[
-                            TestSemantics(
-                              label: 'one',
-                              textDirection: TextDirection.ltr,
-                              flags: <SemanticsFlag>[
-                                SemanticsFlag.isFocused,
-                                SemanticsFlag.isFocusable,
-                              ],
-                              tags: <SemanticsTag>[const SemanticsTag('RenderViewport.twoPane')],
-                              actions: <SemanticsAction>[SemanticsAction.tap],
-                            ),
-                            TestSemantics(
-                              label: 'two',
-                              textDirection: TextDirection.ltr,
-                              flags: <SemanticsFlag>[SemanticsFlag.isFocusable],
-                              tags: <SemanticsTag>[const SemanticsTag('RenderViewport.twoPane')],
-                              actions: <SemanticsAction>[SemanticsAction.tap],
-                            ),
-                            TestSemantics(
-                              label: 'three',
-                              textDirection: TextDirection.ltr,
-                              flags: <SemanticsFlag>[SemanticsFlag.isFocusable],
-                              tags: <SemanticsTag>[const SemanticsTag('RenderViewport.twoPane')],
-                              actions: <SemanticsAction>[SemanticsAction.tap],
-                            ),
-                            TestSemantics(
-                              label: 'four',
-                              textDirection: TextDirection.ltr,
-                              flags: <SemanticsFlag>[SemanticsFlag.isFocusable],
-                              tags: <SemanticsTag>[const SemanticsTag('RenderViewport.twoPane')],
-                              actions: <SemanticsAction>[SemanticsAction.tap],
-                            ),
+                            SemanticsFlag.isFocused,
+                            SemanticsFlag.isFocusable,
                           ],
+                          tags: <SemanticsTag>[const SemanticsTag('RenderViewport.twoPane')],
+                          actions: <SemanticsAction>[SemanticsAction.tap],
+                        ),
+                        TestSemantics(
+                          label: 'two',
+                          textDirection: TextDirection.ltr,
+                          flags: <SemanticsFlag>[SemanticsFlag.isFocusable],
+                          tags: <SemanticsTag>[const SemanticsTag('RenderViewport.twoPane')],
+                          actions: <SemanticsAction>[SemanticsAction.tap],
+                        ),
+                        TestSemantics(
+                          label: 'three',
+                          textDirection: TextDirection.ltr,
+                          flags: <SemanticsFlag>[SemanticsFlag.isFocusable],
+                          tags: <SemanticsTag>[const SemanticsTag('RenderViewport.twoPane')],
+                          actions: <SemanticsAction>[SemanticsAction.tap],
+                        ),
+                        TestSemantics(
+                          label: 'four',
+                          textDirection: TextDirection.ltr,
+                          flags: <SemanticsFlag>[SemanticsFlag.isFocusable],
+                          tags: <SemanticsTag>[const SemanticsTag('RenderViewport.twoPane')],
+                          actions: <SemanticsAction>[SemanticsAction.tap],
                         ),
                       ],
                     ),
@@ -1380,7 +1376,6 @@ void main() {
                 ),
               ],
             ),
-            TestSemantics(),
           ],
         ),
       ],