ScrollController creation dispatching for memory leaks tracking (#133759)

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

@@ -884,6 +884,7 @@ class _ModalScopeState<T> extends State<_ModalScope<T>> {
   @override
   void dispose() {
     focusScopeNode.dispose();
+    primaryScrollController.dispose();
     super.dispose();
   }
 

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

@@ -65,7 +65,11 @@ class ScrollController extends ChangeNotifier {
     this.debugLabel,
     this.onAttach,
     this.onDetach,
-  }) : _initialScrollOffset = initialScrollOffset;
+  }) : _initialScrollOffset = initialScrollOffset {
+    if (kFlutterMemoryAllocationsEnabled) {
+      maybeDispatchObjectCreation();
+    }
+  }
 
   /// The initial value to use for [offset].
   ///

packages/flutter/test/material/app_bar_test.dart

@@ -1609,40 +1609,45 @@ void main() {
     // Generates a MaterialApp with a SliverAppBar in a CustomScrollView.
     // The first cell of the scroll view contains a button at its top, and is
     // initially scrolled so that it is beneath the SliverAppBar.
-    Widget buildWidget({
+    (ScrollController, Widget) buildWidget({
       required bool forceMaterialTransparency,
       required VoidCallback onPressed
     }) {
       const double appBarHeight = 120;
-      return MaterialApp(
+      final ScrollController controller = ScrollController(initialScrollOffset: appBarHeight);
-        home: Scaffold(
+
-          body: CustomScrollView(
+      return (
-            controller: ScrollController(initialScrollOffset:appBarHeight),
+          controller,
-            slivers: <Widget>[
+          MaterialApp(
-              SliverAppBar(
+          home: Scaffold(
-                collapsedHeight: appBarHeight,
+            body: CustomScrollView(
-                expandedHeight: appBarHeight,
+              controller: controller,
-                pinned: true,
+              slivers: <Widget>[
-                elevation: 0,
+                SliverAppBar(
-                backgroundColor: Colors.transparent,
+                  collapsedHeight: appBarHeight,
-                forceMaterialTransparency: forceMaterialTransparency,
+                  expandedHeight: appBarHeight,
-                title: const Text('AppBar'),
+                  pinned: true,
+                  elevation: 0,
+                  backgroundColor: Colors.transparent,
+                  forceMaterialTransparency: forceMaterialTransparency,
+                  title: const Text('AppBar'),
+                ),
+                SliverList(
+                  delegate: SliverChildBuilderDelegate((BuildContext context, int index) {
+                    return SizedBox(
+                      height: appBarHeight,
+                      child: index == 0
+                        ? Align(
+                            alignment: Alignment.topCenter,
+                            child: TextButton(onPressed: onPressed, child: const Text('press')))
+                        : const SizedBox(),
+                    );
+                  },
+                  childCount: 20,
+                ),
               ),
-              SliverList(
+            ]),
-                delegate: SliverChildBuilderDelegate((BuildContext context, int index) {
+          ),
-                  return SizedBox(
-                    height: appBarHeight,
-                    child: index == 0
-                      ? Align(
-                          alignment: Alignment.topCenter,
-                          child: TextButton(onPressed: onPressed, child: const Text('press')))
-                      : const SizedBox(),
-                  );
-                },
-                childCount: 20,
-              ),
-            ),
-          ]),
         ),
       );
     }
@@ -1650,7 +1655,7 @@ void main() {
     testWidgetsWithLeakTracking(
         'forceMaterialTransparency == true allows gestures beneath the app bar', (WidgetTester tester) async {
       bool buttonWasPressed = false;
-      final Widget widget = buildWidget(
+      final (ScrollController controller, Widget widget) = buildWidget(
         forceMaterialTransparency:true,
         onPressed:() { buttonWasPressed = true; },
       );
@@ -1663,6 +1668,8 @@ void main() {
       await tester.tap(buttonFinder);
       await tester.pump();
       expect(buttonWasPressed, isTrue);
+
+      controller.dispose();
     });
 
     testWidgetsWithLeakTracking(
@@ -1672,7 +1679,7 @@ void main() {
       WidgetController.hitTestWarningShouldBeFatal = false;
 
       bool buttonWasPressed = false;
-      final Widget widget = buildWidget(
+      final (ScrollController controller, Widget widget) = buildWidget(
         forceMaterialTransparency:false,
         onPressed:() { buttonWasPressed = true; },
       );
@@ -1685,6 +1692,8 @@ void main() {
       await tester.tap(buttonFinder, warnIfMissed:false);
       await tester.pump();
       expect(buttonWasPressed, isFalse);
+
+      controller.dispose();
     });
   });
 
@@ -4295,6 +4304,8 @@ void main() {
         );
 
         expect(tester.takeException(), isNull);
+
+        controller.dispose();
       });
 
       testWidgetsWithLeakTracking('does not trigger on horizontal scroll', (WidgetTester tester) async {

packages/flutter/test/material/page_selector_test.dart

@@ -84,7 +84,14 @@ void main() {
     await tester.pump();
     expect(tabController.index, 2);
     expect(indicatorColors(tester), const <Color>[kUnselectedColor, kUnselectedColor, kSelectedColor]);
-  });
+  },
+  // TODO(someone): remove after fixing
+  // https://github.com/flutter/flutter/issues/133755
+  leakTrackingTestConfig: const LeakTrackingTestConfig(
+    notDisposedAllowList: <String, int?>{
+      'PageController': 1,
+    },
+  ));
 
   testWidgetsWithLeakTracking('PageSelector responds correctly to TabController.animateTo()', (WidgetTester tester) async {
     final TabController tabController = TabController(
@@ -127,7 +134,14 @@ void main() {
     await tester.pumpAndSettle();
     expect(tabController.index, 2);
     expect(indicatorColors(tester), const <Color>[kUnselectedColor, kUnselectedColor, kSelectedColor]);
-  });
+  },
+  // TODO(someone): remove after fixing
+  // https://github.com/flutter/flutter/issues/133755
+  leakTrackingTestConfig: const LeakTrackingTestConfig(
+    notDisposedAllowList: <String, int?>{
+      'PageController': 1,
+    },
+  ));
 
   testWidgetsWithLeakTracking('PageSelector responds correctly to TabBarView drags', (WidgetTester tester) async {
     final TabController tabController = TabController(
@@ -185,8 +199,14 @@ void main() {
     await tester.fling(find.byType(TabBarView), const Offset(100.0, 0.0), 1000.0);
     await tester.pumpAndSettle();
     expect(indicatorColors(tester), const <Color>[kUnselectedColor, kSelectedColor, kUnselectedColor]);
-
+  },
-  });
+  // TODO(someone): remove after fixing
+  // https://github.com/flutter/flutter/issues/133755
+  leakTrackingTestConfig: const LeakTrackingTestConfig(
+    notDisposedAllowList: <String, int?>{
+      'PageController': 1,
+    },
+  ));
 
   testWidgetsWithLeakTracking('PageSelector indicatorColors', (WidgetTester tester) async {
     const Color kRed = Color(0xFFFF0000);
@@ -205,7 +225,14 @@ void main() {
     tabController.index = 0;
     await tester.pumpAndSettle();
     expect(indicatorColors(tester), const <Color>[kBlue, kRed, kRed]);
-  });
+  },
+  // TODO(someone): remove after fixing
+  // https://github.com/flutter/flutter/issues/133755
+  leakTrackingTestConfig: const LeakTrackingTestConfig(
+    notDisposedAllowList: <String, int?>{
+      'PageController': 1,
+    },
+  ));
 
   testWidgets('PageSelector indicatorSize', (WidgetTester tester) async {
     final TabController tabController = TabController(
@@ -228,7 +255,7 @@ void main() {
     expect(tester.getSize(find.byType(TabPageSelector)).height, 24.0);
   });
 
-    testWidgetsWithLeakTracking('PageSelector circle border', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('PageSelector circle border', (WidgetTester tester) async {
     final TabController tabController = TabController(
       vsync: const TestVSync(),
       initialIndex: 1,
@@ -272,5 +299,12 @@ void main() {
     for (final TabPageSelectorIndicator indicator in indicators) {
       expect(indicator.borderStyle, BorderStyle.solid);
     }
-  });
+  },
+  // TODO(someone): remove after fixing
+  // https://github.com/flutter/flutter/issues/133755
+  leakTrackingTestConfig: const LeakTrackingTestConfig(
+    notDisposedAllowList: <String, int?>{
+      'PageController': 1,
+    },
+  ));
 }

packages/flutter/test/material/refresh_indicator_test.dart

@@ -423,6 +423,8 @@ void main() {
     expect(controller.offset, greaterThan(lastScrollOffset));
     expect(controller.offset, lessThan(0.0));
     expect(refreshCalled, isTrue);
+
+    controller.dispose();
   }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
 
   testWidgetsWithLeakTracking('RefreshIndicator does not force child to relayout', (WidgetTester tester) async {
@@ -618,6 +620,8 @@ void main() {
     await tester.pump(const Duration(seconds: 1)); // finish the scroll animation
     await tester.pump(const Duration(seconds: 1)); // finish the indicator settle animation
     expect(tester.getCenter(find.byType(RefreshProgressIndicator)).dy, lessThan(300.0));
+
+    scrollController.dispose();
   });
 
   testWidgetsWithLeakTracking('Reverse RefreshIndicator(anywhere mode) should be shown when dragging from non-zero scroll position', (WidgetTester tester) async {
@@ -654,6 +658,8 @@ void main() {
     await tester.pump(const Duration(seconds: 1)); // finish the scroll animation
     await tester.pump(const Duration(seconds: 1)); // finish the indicator settle animation
     expect(tester.getCenter(find.byType(RefreshProgressIndicator)).dy, lessThan(300.0));
+
+    scrollController.dispose();
   });
 
   // Regression test for https://github.com/flutter/flutter/issues/71936
@@ -691,6 +697,8 @@ void main() {
     await tester.pump(const Duration(seconds: 1)); // finish the scroll animation
     await tester.pump(const Duration(seconds: 1)); // finish the indicator settle animation
     expect(find.byType(RefreshProgressIndicator), findsNothing);
+
+    scrollController.dispose();
   });
 
   testWidgetsWithLeakTracking('Top RefreshIndicator(onEdge mode) should not be shown when dragging from non-zero scroll position', (WidgetTester tester) async {
@@ -725,6 +733,8 @@ void main() {
     await tester.pump(const Duration(seconds: 1)); // finish the scroll animation
     await tester.pump(const Duration(seconds: 1)); // finish the indicator settle animation
     expect(find.byType(RefreshProgressIndicator), findsNothing);
+
+    scrollController.dispose();
   });
 
   testWidgetsWithLeakTracking('Reverse RefreshIndicator(onEdge mode) should be shown when dragging from non-zero scroll position', (WidgetTester tester) async {
@@ -760,6 +770,8 @@ void main() {
     await tester.pump(const Duration(seconds: 1)); // finish the scroll animation
     await tester.pump(const Duration(seconds: 1)); // finish the indicator settle animation
     expect(find.byType(RefreshProgressIndicator), findsNothing);
+
+    scrollController.dispose();
   });
 
   testWidgetsWithLeakTracking('ScrollController.jumpTo should not trigger the refresh indicator', (WidgetTester tester) async {
@@ -792,6 +804,8 @@ void main() {
     await tester.pump(const Duration(seconds: 1)); // finish the indicator hide animation
 
     expect(refreshCalled, false);
+
+    scrollController.dispose();
   });
 
   testWidgetsWithLeakTracking('RefreshIndicator.adaptive', (WidgetTester tester) async {

packages/flutter/test/material/scrollbar_test.dart

@@ -203,6 +203,8 @@ void main() {
     await tester.pumpWidget(viewWithScroll());
     final AssertionError exception = tester.takeException() as AssertionError;
     expect(exception, isAssertionError);
+
+    controller.dispose();
   });
 
   testWidgetsWithLeakTracking('On first render with thumbVisibility: true, the thumb shows', (WidgetTester tester) async {
@@ -229,6 +231,8 @@ void main() {
     await tester.pumpWidget(viewWithScroll());
     await tester.pumpAndSettle();
     expect(find.byType(Scrollbar), paints..rect());
+
+    controller.dispose();
   });
 
   testWidgetsWithLeakTracking('On first render with thumbVisibility: true, the thumb shows with PrimaryScrollController', (WidgetTester tester) async {
@@ -261,6 +265,8 @@ void main() {
     await tester.pumpWidget(viewWithScroll());
     await tester.pumpAndSettle();
     expect(find.byType(Scrollbar), paints..rect());
+
+    controller.dispose();
   });
 
   testWidgetsWithLeakTracking(
@@ -314,6 +320,8 @@ void main() {
       await tester.pumpWidget(viewWithScroll());
       final AssertionError exception = tester.takeException() as AssertionError;
       expect(exception, isAssertionError);
+
+      controller.dispose();
     },
   );
 
@@ -341,6 +349,8 @@ void main() {
     await tester.pumpWidget(viewWithScroll());
     await tester.pumpAndSettle();
     expect(find.byType(Scrollbar), paints..rect());
+
+    controller.dispose();
   });
 
   testWidgetsWithLeakTracking('On first render with thumbVisibility: true, the thumb shows with PrimaryScrollController', (WidgetTester tester) async {
@@ -373,6 +383,8 @@ void main() {
     await tester.pumpWidget(viewWithScroll());
     await tester.pumpAndSettle();
     expect(find.byType(Scrollbar), paints..rect());
+
+    controller.dispose();
   });
 
   testWidgetsWithLeakTracking('On first render with thumbVisibility: false, the thumb is hidden', (WidgetTester tester) async {
@@ -399,6 +411,8 @@ void main() {
     await tester.pumpWidget(viewWithScroll());
     await tester.pumpAndSettle();
     expect(find.byType(Scrollbar), isNot(paints..rect()));
+
+    controller.dispose();
   });
 
   testWidgetsWithLeakTracking(
@@ -452,6 +466,8 @@ void main() {
       await tester.pumpAndSettle();
       // Scrollbar is not showing after scroll finishes
       expect(find.byType(Scrollbar), isNot(paints..rect()));
+
+      controller.dispose();
     },
   );
 
@@ -501,6 +517,8 @@ void main() {
       await tester.pumpAndSettle();
       // Scrollbar is not showing after scroll finishes
       expect(find.byType(Scrollbar), paints..rect());
+
+      controller.dispose();
     },
   );
 
@@ -561,6 +579,8 @@ void main() {
       await tester.pumpAndSettle();
       // Scrollbar thumb is showing after scroll finishes and timer ends.
       expect(find.byType(Scrollbar), paints..rect());
+
+      controller.dispose();
     },
   );
 
@@ -610,6 +630,8 @@ void main() {
       await tester.tap(find.byType(FloatingActionButton));
       await tester.pumpAndSettle();
       expect(materialScrollbar, isNot(paints..rect()));
+
+      controller.dispose();
     },
   );
 
@@ -673,6 +695,8 @@ void main() {
     ));
 
     await tester.pumpAndSettle();
+
+    controller.dispose();
   });
 
   testWidgetsWithLeakTracking('Tapping the track area pages the Scroll View', (WidgetTester tester) async {
@@ -763,6 +787,8 @@ void main() {
           color: _kAndroidThumbIdleColor,
         ),
     );
+
+    scrollController.dispose();
   });
 
   testWidgets('Scrollbar never goes away until finger lift', (WidgetTester tester) async {
@@ -936,6 +962,8 @@ void main() {
           color: _kAndroidThumbIdleColor,
         ),
     );
+
+    scrollController.dispose();
   });
 
   testWidgetsWithLeakTracking('Scrollbar thumb color completes a hover animation', (WidgetTester tester) async {
@@ -1331,6 +1359,8 @@ void main() {
     expect(find.byType(CupertinoScrollbar), paints..rrect());
     final CupertinoScrollbar scrollbar = tester.widget<CupertinoScrollbar>(find.byType(CupertinoScrollbar));
     expect(scrollbar.controller, isNotNull);
+
+    controller.dispose();
   }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS }));
 
   testWidgetsWithLeakTracking("Scrollbar doesn't show when scroll the inner scrollable widget", (WidgetTester tester) async {
@@ -1463,6 +1493,8 @@ void main() {
     await tester.pumpAndSettle();
     // The offset should not have changed.
     expect(scrollController.offset, scrollAmount);
+
+    scrollController.dispose();
   }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.fuchsia }));
 
   testWidgetsWithLeakTracking('Scrollbar dragging is disabled by default on Android', (WidgetTester tester) async {
@@ -1557,6 +1589,8 @@ void main() {
     // The offset should not have changed.
     expect(scrollController.offset, scrollAmount * 2);
     expect(tapCount, 2);
+
+    scrollController.dispose();
   });
 
   testWidgetsWithLeakTracking('Simultaneous dragging and pointer scrolling does not cause a crash', (WidgetTester tester) async {
@@ -1729,6 +1763,8 @@ void main() {
           color: const Color(0xffbcbcbc),
         ),
     );
+
+    scrollController.dispose();
   });
 
   testWidgetsWithLeakTracking('Scrollbar.thumbVisibility triggers assertion when multiple ScrollPositions are attached.', (WidgetTester tester) async {
@@ -1796,7 +1832,16 @@ void main() {
       error.message,
       contains('The provided ScrollController is currently attached to more than one ScrollPosition.'),
     );
-  });
+
+    scrollController.dispose();
+  },
+  // TODO(someone): remove after fixing
+  // https://github.com/flutter/flutter/issues/133755
+  leakTrackingTestConfig: const LeakTrackingTestConfig(
+    notDisposedAllowList: <String, int?>{
+      'PageController': 2,
+    },
+  ));
 
   testWidgetsWithLeakTracking('Scrollbar scrollOrientation works correctly', (WidgetTester tester) async {
     final ScrollController scrollController = ScrollController();
@@ -1844,5 +1889,7 @@ void main() {
           color: _kAndroidThumbIdleColor,
         ),
     );
+
+    scrollController.dispose();
   });
 }

packages/flutter/test/material/scrollbar_theme_test.dart

@@ -113,6 +113,8 @@ void main() {
           color: const Color(0x80000000),
         ),
     );
+
+    scrollController.dispose();
   }, variant: const TargetPlatformVariant(<TargetPlatform>{
        TargetPlatform.linux,
        TargetPlatform.macOS,
@@ -204,6 +206,8 @@ void main() {
           color: const Color(0xff2196f3),
         ),
     );
+
+    scrollController.dispose();
   }, variant: const TargetPlatformVariant(<TargetPlatform>{
        TargetPlatform.linux,
        TargetPlatform.macOS,
@@ -253,6 +257,8 @@ void main() {
             color: const Color(0xFF000000),
           ),
       );
+
+      scrollController.dispose();
     },
   );
 
@@ -301,6 +307,8 @@ void main() {
         color: _kDefaultIdleThumbColor,
       ),
     );
+
+    scrollController.dispose();
   }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.fuchsia }));
 
   testWidgetsWithLeakTracking('Scrollbar.interactive takes priority over ScrollbarTheme', (WidgetTester tester) async {
@@ -349,6 +357,8 @@ void main() {
         color: _kDefaultIdleThumbColor,
       ),
     );
+
+    scrollController.dispose();
   }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.fuchsia }));
 
   testWidgetsWithLeakTracking('Scrollbar widget properties take priority over theme', (WidgetTester tester) async {
@@ -442,6 +452,8 @@ void main() {
           color: const Color(0x80000000),
         ),
     );
+
+    scrollController.dispose();
   }, variant: const TargetPlatformVariant(<TargetPlatform>{
        TargetPlatform.linux,
        TargetPlatform.macOS,
@@ -451,30 +463,34 @@ void main() {
   );
 
   testWidgetsWithLeakTracking('ThemeData colorScheme is used when no ScrollbarTheme is set', (WidgetTester tester) async {
-    Widget buildFrame(ThemeData appTheme) {
+    (ScrollController, Widget) buildFrame(ThemeData appTheme) {
       final ScrollController scrollController = ScrollController();
-      return MaterialApp(
+      return (
-        theme: appTheme,
+          scrollController,
-        home: ScrollConfiguration(
+          MaterialApp(
-          behavior: const NoScrollbarBehavior(),
+            theme: appTheme,
-          child: Scrollbar(
+            home: ScrollConfiguration(
-            thumbVisibility: true,
+              behavior: const NoScrollbarBehavior(),
-            showTrackOnHover: true,
+              child: Scrollbar(
-            controller: scrollController,
+                thumbVisibility: true,
-            child: SingleChildScrollView(
+                showTrackOnHover: true,
-              controller: scrollController,
+                controller: scrollController,
-              child: const SizedBox(width: 4000.0, height: 4000.0),
+                child: SingleChildScrollView(
+                  controller: scrollController,
+                  child: const SizedBox(width: 4000.0, height: 4000.0),
+                ),
+              ),
             ),
           ),
-        ),
+        );
-      );
     }
 
     // Scrollbar defaults for light themes:
     // - coloring based on ColorScheme.onSurface
-    await tester.pumpWidget(buildFrame(ThemeData(
+    final (ScrollController controller1, Widget frame1) = buildFrame(ThemeData(
       colorScheme: const ColorScheme.light(),
-    )));
+    ));
+    await tester.pumpWidget(frame1);
     await tester.pumpAndSettle();
     // Idle scrollbar behavior
     expect(
@@ -545,9 +561,10 @@ void main() {
 
     // Scrollbar defaults for dark themes:
     // - coloring slightly different based on ColorScheme.onSurface
-    await tester.pumpWidget(buildFrame(ThemeData(
+    final (ScrollController controller2, Widget frame2) = buildFrame(ThemeData(
       colorScheme: const ColorScheme.dark(),
-    )));
+    ));
+    await tester.pumpWidget(frame2);
     await tester.pumpAndSettle(); // Theme change animation
 
     // Idle scrollbar behavior
@@ -610,6 +627,9 @@ void main() {
           color: const Color(0xa6ffffff),
         ),
     );
+
+    controller1.dispose();
+    controller2.dispose();
   }, variant: const TargetPlatformVariant(<TargetPlatform>{
        TargetPlatform.linux,
        TargetPlatform.macOS,
@@ -656,6 +676,8 @@ void main() {
         )
         ..rrect(color: const Color(0xff4caf50)),
     );
+
+    scrollController.dispose();
   }, variant: const TargetPlatformVariant(<TargetPlatform>{
     TargetPlatform.linux,
     TargetPlatform.macOS,

packages/flutter/test/material/tabbed_scrollview_warp_test.dart

@@ -81,5 +81,12 @@ void main() {
     // should not crash.
     await tester.tap(find.text('Tab 2'));
     await tester.pumpAndSettle();
-  });
+  },
+  // TODO(someone): remove after fixing
+  // https://github.com/flutter/flutter/issues/133755
+  leakTrackingTestConfig: const LeakTrackingTestConfig(
+    notDisposedAllowList: <String, int?>{
+      'PageController': 1,
+    },
+  ));
 }

packages/flutter/test/widgets/scroll_controller_test.dart

@@ -4,6 +4,7 @@
 
 import 'dart:ui' as ui;
 
+import 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';
 import 'package:flutter_test/flutter_test.dart';
 
@@ -393,4 +394,21 @@ void main() {
     // should have been true
     expect(isScrolling, isTrue);
   });
+
+  test('$ScrollController dispatches object creation in constructor', () {
+    final List<ObjectEvent> events = <ObjectEvent>[];
+    void listener(ObjectEvent event) {
+      if (event.object.runtimeType == ScrollController) {
+        events.add(event);
+      }
+    }
+    MemoryAllocations.instance.addListener(listener);
+
+    final ScrollController controller = ScrollController();
+
+    expect(events, hasLength(1));
+
+    controller.dispose();
+    MemoryAllocations.instance.removeListener(listener);
+  });
 }