Mark routes as opaque when added without animation (#43756)

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

@@ -86,8 +86,7 @@ class OverlayEntry {
     if (_opaque == value)
       return;
     _opaque = value;
-    assert(_overlay != null);
-    _overlay._didChangeEntryOpacity();
+    _overlay?._didChangeEntryOpacity();
   }
 
   /// Whether this entry must be included in the tree even if there is a fully

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

@@ -184,7 +184,7 @@ abstract class TransitionRoute<T> extends OverlayRoute<T> {
   TickerFuture didPush() {
     assert(_controller != null, '$runtimeType.didPush called before calling install() or after calling dispose().');
     assert(!_transitionCompleter.isCompleted, 'Cannot reuse a $runtimeType after disposing it.');
-    _animation.addStatusListener(_handleStatusChanged);
+    _didPushOrReplace();
     super.didPush();
     return _controller.forward();
   }
@@ -195,10 +195,19 @@ abstract class TransitionRoute<T> extends OverlayRoute<T> {
     assert(!_transitionCompleter.isCompleted, 'Cannot reuse a $runtimeType after disposing it.');
     if (oldRoute is TransitionRoute)
       _controller.value = oldRoute._controller.value;
-    _animation.addStatusListener(_handleStatusChanged);
+    _didPushOrReplace();
     super.didReplace(oldRoute);
   }
 
+  void _didPushOrReplace() {
+    _animation.addStatusListener(_handleStatusChanged);
+    // If the animation is already completed, _handleStatusChanged will not get
+    // a chance to set opaqueness of OverlayEntry.
+    if (_animation.isCompleted && overlayEntries.isNotEmpty) {
+      overlayEntries.first.opaque = opaque;
+    }
+  }
+
   @override
   bool didPop(T result) {
     assert(_controller != null, '$runtimeType.didPop called before calling install() or after calling dispose().');

packages/flutter/test/material/app_test.dart

@@ -241,10 +241,10 @@ void main() {
       ),
     );
 
-    expect(find.text('route "/"'), findsOneWidget);
+    expect(find.text('route "/"', skipOffstage: false), findsOneWidget);
     expect(find.text('route "/a"'), findsOneWidget);
-    expect(find.text('route "/a/b"'), findsNothing);
-    expect(find.text('route "/b"'), findsNothing);
+    expect(find.text('route "/a/b"', skipOffstage: false), findsNothing);
+    expect(find.text('route "/b"', skipOffstage: false), findsNothing);
   });
 
   testWidgets('Return value from pop is correct', (WidgetTester tester) async {
@@ -301,10 +301,10 @@ void main() {
         routes: routes,
       ),
     );
-    expect(find.text('route "/"'), findsOneWidget);
-    expect(find.text('route "/a"'), findsOneWidget);
+    expect(find.text('route "/"', skipOffstage: false), findsOneWidget);
+    expect(find.text('route "/a"', skipOffstage: false), findsOneWidget);
     expect(find.text('route "/a/b"'), findsOneWidget);
-    expect(find.text('route "/b"'), findsNothing);
+    expect(find.text('route "/b"', skipOffstage: false), findsNothing);
   });
 
   testWidgets('Initial route with missing step', (WidgetTester tester) async {
@@ -343,9 +343,9 @@ void main() {
         routes: routes,
       ),
     );
-    expect(find.text('route "/"'), findsOneWidget);
+    expect(find.text('route "/"', skipOffstage: false), findsOneWidget);
     expect(find.text('route "/a"'), findsOneWidget);
-    expect(find.text('route "/b"'), findsNothing);
+    expect(find.text('route "/b"', skipOffstage: false), findsNothing);
 
     // changing initialRoute has no effect
     await tester.pumpWidget(
@@ -354,15 +354,15 @@ void main() {
         routes: routes,
       ),
     );
-    expect(find.text('route "/"'), findsOneWidget);
+    expect(find.text('route "/"', skipOffstage: false), findsOneWidget);
     expect(find.text('route "/a"'), findsOneWidget);
-    expect(find.text('route "/b"'), findsNothing);
+    expect(find.text('route "/b"', skipOffstage: false), findsNothing);
 
     // removing it has no effect
     await tester.pumpWidget(MaterialApp(routes: routes));
-    expect(find.text('route "/"'), findsOneWidget);
+    expect(find.text('route "/"', skipOffstage: false), findsOneWidget);
     expect(find.text('route "/a"'), findsOneWidget);
-    expect(find.text('route "/b"'), findsNothing);
+    expect(find.text('route "/b"', skipOffstage: false), findsNothing);
   });
 
   testWidgets('onGenerateRoute / onUnknownRoute', (WidgetTester tester) async {

packages/flutter/test/widgets/heroes_test.dart

@@ -1754,7 +1754,9 @@ Future<void> main() async {
       routes: routes,
       initialRoute: '/two',
     ));
-    expect(find.text('two'), findsOneWidget);
+    expect(tester.takeException(), isNull);
+    expect(find.text('two'), findsNothing);
+    expect(find.text('three'), findsOneWidget);
   });
 
   testWidgets('Can push/pop on outer Navigator if nested Navigator contains Heroes', (WidgetTester tester) async {

packages/flutter/test/widgets/navigator_test.dart

@@ -994,15 +994,15 @@ void main() {
     );
 
     // The initial route /A/B/C should've been pushed successfully.
-    expect(find.byKey(keyRoot), findsOneWidget);
-    expect(find.byKey(keyA), findsOneWidget);
+    expect(find.byKey(keyRoot, skipOffstage: false), findsOneWidget);
+    expect(find.byKey(keyA, skipOffstage: false), findsOneWidget);
     expect(find.byKey(keyABC), findsOneWidget);
 
     keyNav.currentState.pop();
     await tester.pumpAndSettle();
-    expect(find.byKey(keyRoot), findsOneWidget);
+    expect(find.byKey(keyRoot, skipOffstage: false), findsOneWidget);
     expect(find.byKey(keyA), findsOneWidget);
-    expect(find.byKey(keyABC), findsNothing);
+    expect(find.byKey(keyABC, skipOffstage: false), findsNothing);
   });
 
   testWidgets('The full initial route has to be matched', (WidgetTester tester) async {
@@ -1089,4 +1089,111 @@ void main() {
     });
   });
 
+  testWidgets('OverlayEntry of topmost initial route is marked as opaque', (WidgetTester tester) async {
+    // Regression test for https://github.com/flutter/flutter/issues/38038.
+
+    final Key root = UniqueKey();
+    final Key intermediate = UniqueKey();
+    final GlobalKey topmost = GlobalKey();
+    await tester.pumpWidget(
+      MaterialApp(
+        initialRoute: '/A/B',
+        routes: <String, WidgetBuilder>{
+          '/': (BuildContext context) => Container(key: root),
+          '/A': (BuildContext context) => Container(key: intermediate),
+          '/A/B': (BuildContext context) => Container(key: topmost),
+        },
+      ),
+    );
+
+    expect(ModalRoute.of(topmost.currentContext).overlayEntries.first.opaque, isTrue);
+
+    expect(find.byKey(root), findsNothing);  // hidden by opaque Route
+    expect(find.byKey(intermediate), findsNothing);  // hidden by opaque Route
+    expect(find.byKey(topmost), findsOneWidget);
+  });
+
+  testWidgets('OverlayEntry of topmost route is set to opaque after Push', (WidgetTester tester) async {
+    // Regression test for https://github.com/flutter/flutter/issues/38038.
+
+    final GlobalKey<NavigatorState> navigator = GlobalKey<NavigatorState>();
+    await tester.pumpWidget(
+      MaterialApp(
+        navigatorKey: navigator,
+        initialRoute: '/',
+        onGenerateRoute: (RouteSettings settings) {
+          return NoAnimationPageRoute(
+            pageBuilder: (_) => Container(key: ValueKey<String>(settings.name)),
+          );
+        },
+      ),
+    );
+    expect(find.byKey(const ValueKey<String>('/')), findsOneWidget);
+
+    navigator.currentState.pushNamed('/A');
+    await tester.pump();
+
+    final BuildContext topMostContext = tester.element(find.byKey(const ValueKey<String>('/A')));
+    expect(ModalRoute.of(topMostContext).overlayEntries.first.opaque, isTrue);
+
+    expect(find.byKey(const ValueKey<String>('/')), findsNothing);  // hidden by /A
+    expect(find.byKey(const ValueKey<String>('/A')), findsOneWidget);
+  });
+
+  testWidgets('OverlayEntry of topmost route is set to opaque after Replace', (WidgetTester tester) async {
+    // Regression test for https://github.com/flutter/flutter/issues/38038.
+
+    final GlobalKey<NavigatorState> navigator = GlobalKey<NavigatorState>();
+    await tester.pumpWidget(
+      MaterialApp(
+        navigatorKey: navigator,
+        initialRoute: '/A/B',
+        onGenerateRoute: (RouteSettings settings) {
+          return NoAnimationPageRoute(
+            pageBuilder: (_) => Container(key: ValueKey<String>(settings.name)),
+          );
+        },
+      ),
+    );
+    expect(find.byKey(const ValueKey<String>('/')), findsNothing);
+    expect(find.byKey(const ValueKey<String>('/A')), findsNothing);
+    expect(find.byKey(const ValueKey<String>('/A/B')), findsOneWidget);
+
+    final Route<dynamic> oldRoute = ModalRoute.of(
+      tester.element(find.byKey(const ValueKey<String>('/A'), skipOffstage: false)),
+    );
+    final Route<void> newRoute = NoAnimationPageRoute(
+      pageBuilder: (_) => Container(key: const ValueKey<String>('/C')),
+    );
+
+    navigator.currentState.replace<void>(oldRoute: oldRoute, newRoute: newRoute);
+    await tester.pump();
+
+    expect(newRoute.overlayEntries.first.opaque, isTrue);
+
+    expect(find.byKey(const ValueKey<String>('/')), findsNothing);  // hidden by /A/B
+    expect(find.byKey(const ValueKey<String>('/A')), findsNothing);  // replaced
+    expect(find.byKey(const ValueKey<String>('/C')), findsNothing);  // hidden by /A/B
+    expect(find.byKey(const ValueKey<String>('/A/B')), findsOneWidget);
+
+    navigator.currentState.pop();
+    await tester.pumpAndSettle();
+
+    expect(find.byKey(const ValueKey<String>('/')), findsNothing);  // hidden by /C
+    expect(find.byKey(const ValueKey<String>('/A')), findsNothing);  // replaced
+    expect(find.byKey(const ValueKey<String>('/A/B')), findsNothing); // popped
+    expect(find.byKey(const ValueKey<String>('/C')), findsOneWidget);
+  });
+}
+
+class NoAnimationPageRoute extends PageRouteBuilder<void> {
+  NoAnimationPageRoute({WidgetBuilder pageBuilder})
+      : super(pageBuilder: (BuildContext context, __, ___) {
+          return pageBuilder(context);
+        });
+
+  @override
+  AnimationController createAnimationController() {
+    return super.createAnimationController()..value = 1.0;
+  }
 }

packages/flutter/test/widgets/overlay_test.dart

@@ -657,4 +657,45 @@ void main() {
       ),
     );
   });
+
+  testWidgets('OverlayEntry.opaque can be changed when OverlayEntry is not part of an Overlay (yet)', (WidgetTester tester) async {
+    final GlobalKey<OverlayState> overlayKey = GlobalKey<OverlayState>();
+    final Key root = UniqueKey();
+    final Key top = UniqueKey();
+    final OverlayEntry rootEntry = OverlayEntry(
+      builder: (BuildContext context) {
+        return Container(key: root);
+      },
+    );
+
+    await tester.pumpWidget(
+      Directionality(
+        textDirection: TextDirection.ltr,
+        child: Overlay(
+          key: overlayKey,
+          initialEntries: <OverlayEntry>[
+            rootEntry,
+          ],
+        ),
+      ),
+    );
+
+    expect(find.byKey(root), findsOneWidget);
+
+    final OverlayEntry newEntry = OverlayEntry(
+      builder: (BuildContext context) {
+        return Container(key: top);
+      },
+    );
+    expect(newEntry.opaque, isFalse);
+    newEntry.opaque = true; // Does neither trigger an assert nor throw.
+    expect(newEntry.opaque, isTrue);
+
+    // The new opaqueness is honored when inserted into an overlay.
+    overlayKey.currentState.insert(newEntry);
+    await tester.pumpAndSettle();
+
+    expect(find.byKey(root), findsNothing);
+    expect(find.byKey(top), findsOneWidget);
+  });
 }