packages/flutter/test/widgets/scroll_behavior_test.dart - mirrors/flutter - Git at Google

 // Copyright 2014 The Flutter Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 import 'package:flutter/foundation.dart';
 import 'package:flutter/gestures.dart';
 import 'package:flutter/widgets.dart';
 import 'package:flutter_test/flutter_test.dart';

 late GestureVelocityTrackerBuilder lastCreatedBuilder;
 class TestScrollBehavior extends ScrollBehavior {
   const TestScrollBehavior(this.flag);

   final bool flag;

   @override
   ScrollPhysics getScrollPhysics(BuildContext context) {
     return flag
       ? const ClampingScrollPhysics()
       : const BouncingScrollPhysics();
   }

   @override
   bool shouldNotify(TestScrollBehavior old) => flag != old.flag;

   @override
   GestureVelocityTrackerBuilder velocityTrackerBuilder(BuildContext context) {
       lastCreatedBuilder = flag
         ? (PointerEvent ev) => VelocityTracker.withKind(ev.kind)
         : (PointerEvent ev) => IOSScrollViewFlingVelocityTracker(ev.kind);
       return lastCreatedBuilder;
   }
 }

 void main() {
   testWidgets('Assert in buildScrollbar that controller != null when using it', (WidgetTester tester) async {
     const ScrollBehavior defaultBehavior = ScrollBehavior();
     late BuildContext capturedContext;

     await tester.pumpWidget(ScrollConfiguration(
       // Avoid the default ones here.
       behavior: const ScrollBehavior().copyWith(scrollbars: false),
       child: SingleChildScrollView(
         child: Builder(
           builder: (BuildContext context) {
             capturedContext = context;
             return Container(height: 1000.0);
           },
         ),
       ),
     ));

     const ScrollableDetails details = ScrollableDetails(direction: AxisDirection.down);
     final Widget child = Container();

     switch (defaultTargetPlatform) {
       case TargetPlatform.android:
       case TargetPlatform.fuchsia:
       case TargetPlatform.iOS:
         // Does not throw if we aren't using it.
         defaultBehavior.buildScrollbar(capturedContext, child, details);
       case TargetPlatform.linux:
       case TargetPlatform.macOS:
       case TargetPlatform.windows:
         expect(
           () {
             defaultBehavior.buildScrollbar(capturedContext, child, details);
           },
           throwsA(
             isA<AssertionError>().having((AssertionError error) => error.toString(),
               'description', contains('details.controller != null')),
           ),
         );
     }
   }, variant: TargetPlatformVariant.all());

   // Regression test for https://github.com/flutter/flutter/issues/89681
   testWidgets('_WrappedScrollBehavior shouldNotify test', (WidgetTester tester) async {
     final ScrollBehavior behavior1 = const ScrollBehavior().copyWith();
     final ScrollBehavior behavior2 = const ScrollBehavior().copyWith();

     expect(behavior1.shouldNotify(behavior2), false);
   });

   testWidgets('Inherited ScrollConfiguration changed', (WidgetTester tester) async {
     final GlobalKey key = GlobalKey(debugLabel: 'scrollable');
     TestScrollBehavior? behavior;
     late ScrollPositionWithSingleContext position;

     final Widget scrollView = SingleChildScrollView(
       key: key,
       child: Builder(
         builder: (BuildContext context) {
           behavior = ScrollConfiguration.of(context) as TestScrollBehavior;
           position = Scrollable.of(context).position as ScrollPositionWithSingleContext;
           return Container(height: 1000.0);
         },
       ),
     );

     await tester.pumpWidget(
       ScrollConfiguration(
         behavior: const TestScrollBehavior(true),
         child: scrollView,
       ),
     );

     expect(behavior, isNotNull);
     expect(behavior!.flag, isTrue);
     expect(position.physics, isA<ClampingScrollPhysics>());
     expect(lastCreatedBuilder(const PointerDownEvent()), isA<VelocityTracker>());
     ScrollMetrics metrics = position.copyWith();
     expect(metrics.extentAfter, equals(400.0));
     expect(metrics.viewportDimension, equals(600.0));

     // Same Scrollable, different ScrollConfiguration
     await tester.pumpWidget(
       ScrollConfiguration(
         behavior: const TestScrollBehavior(false),
         child: scrollView,
       ),
     );

     expect(behavior, isNotNull);
     expect(behavior!.flag, isFalse);
     expect(position.physics, isA<BouncingScrollPhysics>());
     expect(lastCreatedBuilder(const PointerDownEvent()), isA<IOSScrollViewFlingVelocityTracker>());
     // Regression test for https://github.com/flutter/flutter/issues/5856
     metrics = position.copyWith();
     expect(metrics.extentAfter, equals(400.0));
     expect(metrics.viewportDimension, equals(600.0));
   });

   testWidgets('ScrollBehavior default android overscroll indicator', (WidgetTester tester) async {
     await tester.pumpWidget(
       Directionality(
         textDirection: TextDirection.ltr,
         child: ScrollConfiguration(
           behavior: const ScrollBehavior(),
           child: ListView(
             children: const <Widget>[
               SizedBox(
                 height: 1000.0,
                 width: 1000.0,
                 child: Text('Test'),
               ),
             ],
           ),
         ),
       ),
     );

     expect(find.byType(StretchingOverscrollIndicator), findsNothing);
     expect(find.byType(GlowingOverscrollIndicator), findsOneWidget);
   }, variant: TargetPlatformVariant.only(TargetPlatform.android));

   testWidgets('ScrollBehavior multitouchDragStrategy test - 1', (WidgetTester tester) async {
     const ScrollBehavior behavior1 = ScrollBehavior();
     final ScrollBehavior behavior2 = const ScrollBehavior().copyWith(
       multitouchDragStrategy: MultitouchDragStrategy.sumAllPointers
     );
     final ScrollController controller = ScrollController();
     addTearDown(() => controller.dispose());

     Widget buildFrame(ScrollBehavior behavior) {
       return Directionality(
         textDirection: TextDirection.ltr,
         child: ScrollConfiguration(
           behavior: behavior,
           child: ListView(
             controller: controller,
             children: const <Widget>[
               SizedBox(
                 height: 1000.0,
                 width: 1000.0,
                 child: Text('I Love Flutter!'),
               ),
             ],
           ),
         ),
       );
     }

     await tester.pumpWidget(buildFrame(behavior1));

     expect(controller.position.pixels, 0.0);

     final Offset listLocation = tester.getCenter(find.byType(ListView));

     final TestGesture gesture1 = await tester.createGesture(pointer: 1);
     await gesture1.down(listLocation);
     await tester.pump();

     final TestGesture gesture2 = await tester.createGesture(pointer: 2);
     await gesture2.down(listLocation);
     await tester.pump();

     await gesture1.moveBy(const Offset(0, -50));
     await tester.pump();

     await gesture2.moveBy(const Offset(0, -50));
     await tester.pump();

     // The default multitouchDragStrategy is 'latestPointer' or 'averageBoundaryPointers,
     // the received delta should be 50.0.
     expect(controller.position.pixels, 50.0);

     // Change to sumAllPointers.
     await tester.pumpWidget(buildFrame(behavior2));

     await gesture1.moveBy(const Offset(0, -50));
     await tester.pump();

     await gesture2.moveBy(const Offset(0, -50));
     await tester.pump();

     // All active pointers be tracked.
     expect(controller.position.pixels, 50.0 + 50.0 + 50.0);
   }, variant: TargetPlatformVariant.all());

   testWidgets('ScrollBehavior multitouchDragStrategy test (non-Apple platforms) - 2', (WidgetTester tester) async {
     const ScrollBehavior behavior1 = ScrollBehavior();
     final ScrollBehavior behavior2 = const ScrollBehavior().copyWith(
         multitouchDragStrategy: MultitouchDragStrategy.averageBoundaryPointers
     );
     final ScrollController controller = ScrollController();
     late BuildContext capturedContext;
     addTearDown(() => controller.dispose());

     Widget buildFrame(ScrollBehavior behavior) {
       return Directionality(
         textDirection: TextDirection.ltr,
         child: ScrollConfiguration(
           behavior: behavior,
           child: Builder(
             builder: (BuildContext context) {
               capturedContext = context;
               return ListView(
               controller: controller,
               children: const <Widget>[
                 SizedBox(
                   height: 1000.0,
                   width: 1000.0,
                   child: Text('I Love Flutter!'),
                 ),
               ],
               );
             },
           ),
         ),
       );
     }

     await tester.pumpWidget(buildFrame(behavior1));

     expect(controller.position.pixels, 0.0);

     final Offset listLocation = tester.getCenter(find.byType(ListView));

     final TestGesture gesture1 = await tester.createGesture(pointer: 1);
     await gesture1.down(listLocation);
     await tester.pump();

     final TestGesture gesture2 = await tester.createGesture(pointer: 2);
     await gesture2.down(listLocation);
     await tester.pump();

     await gesture1.moveBy(const Offset(0, -50));
     await tester.pump();

     await gesture2.moveBy(const Offset(0, -40));
     await tester.pump();

     // The default multitouchDragStrategy is latestPointer.
     // Only the latest active pointer be tracked.
     final ScrollBehavior scrollBehavior = ScrollConfiguration.of(capturedContext);
     expect(scrollBehavior.getMultitouchDragStrategy(capturedContext), MultitouchDragStrategy.latestPointer);
     expect(controller.position.pixels, 40.0);

     // Change to averageBoundaryPointers.
     await tester.pumpWidget(buildFrame(behavior2));

     await gesture1.moveBy(const Offset(0, -70));
     await tester.pump();

     await gesture2.moveBy(const Offset(0, -60));
     await tester.pump();

     expect(controller.position.pixels, 40.0 + 70.0);
   }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.android,  TargetPlatform.linux, TargetPlatform.fuchsia, TargetPlatform.windows }));

   testWidgets('ScrollBehavior multitouchDragStrategy test (Apple platforms) - 3', (WidgetTester tester) async {
     const ScrollBehavior behavior1 = ScrollBehavior();
     final ScrollBehavior behavior2 = const ScrollBehavior().copyWith(
         multitouchDragStrategy: MultitouchDragStrategy.latestPointer
     );
     final ScrollController controller = ScrollController();
     late BuildContext capturedContext;
     addTearDown(() => controller.dispose());

     Widget buildFrame(ScrollBehavior behavior) {
       return Directionality(
         textDirection: TextDirection.ltr,
         child: ScrollConfiguration(
           behavior: behavior,
           child: Builder(
             builder: (BuildContext context) {
               capturedContext = context;
               return ListView(
                 controller: controller,
                 children: const <Widget>[
                   SizedBox(
                     height: 1000.0,
                     width: 1000.0,
                     child: Text('I Love Flutter!'),
                   ),
                 ],
               );
             },
           ),
         ),
       );
     }

     await tester.pumpWidget(buildFrame(behavior1));

     expect(controller.position.pixels, 0.0);

     final Offset listLocation = tester.getCenter(find.byType(ListView));

     final TestGesture gesture1 = await tester.createGesture(pointer: 1);
     await gesture1.down(listLocation);
     await tester.pump();

     final TestGesture gesture2 = await tester.createGesture(pointer: 2);
     await gesture2.down(listLocation);
     await tester.pump();

     await gesture1.moveBy(const Offset(0, -40));
     await tester.pump();

     await gesture2.moveBy(const Offset(0, -50));
     await tester.pump();

     // The default multitouchDragStrategy is averageBoundaryPointers.
     final ScrollBehavior scrollBehavior = ScrollConfiguration.of(capturedContext);
     expect(scrollBehavior.getMultitouchDragStrategy(capturedContext), MultitouchDragStrategy.averageBoundaryPointers);
     expect(controller.position.pixels, 50.0);

     // Change to latestPointer.
     await tester.pumpWidget(buildFrame(behavior2));

     await gesture1.moveBy(const Offset(0, -50));
     await tester.pump();

     await gesture2.moveBy(const Offset(0, -40));
     await tester.pump();

     expect(controller.position.pixels, 50.0 + 40.0);
   }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));

   group('ScrollBehavior configuration is maintained over multiple copies', () {
     testWidgets('dragDevices', (WidgetTester tester) async {
       // Regression test for https://github.com/flutter/flutter/issues/91673
       const ScrollBehavior defaultBehavior = ScrollBehavior();
       expect(defaultBehavior.dragDevices, <PointerDeviceKind>{
         PointerDeviceKind.touch,
         PointerDeviceKind.stylus,
         PointerDeviceKind.invertedStylus,
         PointerDeviceKind.trackpad,
         PointerDeviceKind.unknown,
       });

       // Use copyWith to modify drag devices
       final ScrollBehavior onceCopiedBehavior = defaultBehavior.copyWith(
         dragDevices: PointerDeviceKind.values.toSet(),
       );
       expect(onceCopiedBehavior.dragDevices, PointerDeviceKind.values.toSet());

       // Copy again. The previously modified drag devices should carry over.
       final ScrollBehavior twiceCopiedBehavior = onceCopiedBehavior.copyWith();
       expect(twiceCopiedBehavior.dragDevices, PointerDeviceKind.values.toSet());
     });

     testWidgets('physics', (WidgetTester tester) async {
       // Regression test for https://github.com/flutter/flutter/issues/91673
       late ScrollPhysics defaultPhysics;
       late ScrollPhysics onceCopiedPhysics;
       late ScrollPhysics twiceCopiedPhysics;

       await tester.pumpWidget(ScrollConfiguration(
         // Default ScrollBehavior
         behavior: const ScrollBehavior(),
         child: Builder(
           builder: (BuildContext context) {
             final ScrollBehavior defaultBehavior = ScrollConfiguration.of(context);
             // Copy once to change physics
             defaultPhysics = defaultBehavior.getScrollPhysics(context);
             return ScrollConfiguration(
               behavior: defaultBehavior.copyWith(physics: const BouncingScrollPhysics()),
               child: Builder(
                 builder: (BuildContext context) {
                   final ScrollBehavior onceCopiedBehavior = ScrollConfiguration.of(context);
                   onceCopiedPhysics = onceCopiedBehavior.getScrollPhysics(context);
                   return ScrollConfiguration(
                     // Copy again, physics should follow
                     behavior: onceCopiedBehavior.copyWith(),
                     child: Builder(
                       builder: (BuildContext context) {
                         twiceCopiedPhysics = ScrollConfiguration.of(context).getScrollPhysics(context);
                         return SingleChildScrollView(child: Container(height: 1000));
                       }
                     )
                   );
                 }
               )
             );
           }
         ),
       ));

       expect(defaultPhysics, const ClampingScrollPhysics(parent: RangeMaintainingScrollPhysics()));
       expect(onceCopiedPhysics, const BouncingScrollPhysics());
       expect(twiceCopiedPhysics, const BouncingScrollPhysics());
     });

     testWidgets('platform', (WidgetTester tester) async {
       // Regression test for https://github.com/flutter/flutter/issues/91673
       late TargetPlatform defaultPlatform;
       late TargetPlatform onceCopiedPlatform;
       late TargetPlatform twiceCopiedPlatform;

       await tester.pumpWidget(ScrollConfiguration(
         // Default ScrollBehavior
         behavior: const ScrollBehavior(),
         child: Builder(
             builder: (BuildContext context) {
               final ScrollBehavior defaultBehavior = ScrollConfiguration.of(context);
               // Copy once to change physics
               defaultPlatform = defaultBehavior.getPlatform(context);
               return ScrollConfiguration(
                   behavior: defaultBehavior.copyWith(platform: TargetPlatform.fuchsia),
                   child: Builder(
                       builder: (BuildContext context) {
                         final ScrollBehavior onceCopiedBehavior = ScrollConfiguration.of(context);
                         onceCopiedPlatform = onceCopiedBehavior.getPlatform(context);
                         return ScrollConfiguration(
                           // Copy again, physics should follow
                             behavior: onceCopiedBehavior.copyWith(),
                             child: Builder(
                                 builder: (BuildContext context) {
                                   twiceCopiedPlatform = ScrollConfiguration.of(context).getPlatform(context);
                                   return SingleChildScrollView(child: Container(height: 1000));
                                 }
                             )
                         );
                       }
                   )
               );
             }
         ),
       ));

       expect(defaultPlatform, TargetPlatform.android);
       expect(onceCopiedPlatform, TargetPlatform.fuchsia);
       expect(twiceCopiedPlatform, TargetPlatform.fuchsia);
     });

     Widget wrap(ScrollBehavior behavior) {
       return Directionality(
           textDirection: TextDirection.ltr,
           child: MediaQuery(
             data: const MediaQueryData(size: Size(500, 500)),
             child: ScrollConfiguration(
                 behavior: behavior,
                 child: Builder(
                     builder: (BuildContext context) => SingleChildScrollView(child: Container(height: 1000))
                 )
             ),
           )
       );
     }

     testWidgets('scrollbar', (WidgetTester tester) async {
       // Regression test for https://github.com/flutter/flutter/issues/91673
       const  ScrollBehavior defaultBehavior = ScrollBehavior();
       await tester.pumpWidget(wrap(defaultBehavior));
       // Default adds a scrollbar
       expect(find.byType(RawScrollbar), findsOneWidget);
       final ScrollBehavior onceCopiedBehavior = defaultBehavior.copyWith(scrollbars: false);

       await tester.pumpWidget(wrap(onceCopiedBehavior));
       // Copy does not add scrollbar
       expect(find.byType(RawScrollbar), findsNothing);
       final ScrollBehavior twiceCopiedBehavior = onceCopiedBehavior.copyWith();

       await tester.pumpWidget(wrap(twiceCopiedBehavior));
       // Second copy maintains scrollbar setting
       expect(find.byType(RawScrollbar), findsNothing);

       // For default scrollbars
     }, variant: TargetPlatformVariant.desktop());

     testWidgets('overscroll', (WidgetTester tester) async {
       // Regression test for https://github.com/flutter/flutter/issues/91673
       const  ScrollBehavior defaultBehavior = ScrollBehavior();
       await tester.pumpWidget(wrap(defaultBehavior));
       // Default adds a glowing overscroll indicator
       expect(find.byType(GlowingOverscrollIndicator), findsOneWidget);
       final ScrollBehavior onceCopiedBehavior = defaultBehavior.copyWith(overscroll: false);

       await tester.pumpWidget(wrap(onceCopiedBehavior));
       // Copy does not add indicator
       expect(find.byType(GlowingOverscrollIndicator), findsNothing);
       final ScrollBehavior twiceCopiedBehavior = onceCopiedBehavior.copyWith();

       await tester.pumpWidget(wrap(twiceCopiedBehavior));
       // Second copy maintains overscroll setting
       expect(find.byType(GlowingOverscrollIndicator), findsNothing);

       // For default glowing indicator
     }, variant: TargetPlatformVariant.only(TargetPlatform.android));
   });
 }
	// Copyright 2014 The Flutter Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	import 'package:flutter/foundation.dart';
	import 'package:flutter/gestures.dart';
	import 'package:flutter/widgets.dart';
	import 'package:flutter_test/flutter_test.dart';

	late GestureVelocityTrackerBuilder lastCreatedBuilder;
	class TestScrollBehavior extends ScrollBehavior {
	const TestScrollBehavior(this.flag);

	final bool flag;

	@override
	ScrollPhysics getScrollPhysics(BuildContext context) {
	return flag
	? const ClampingScrollPhysics()
	: const BouncingScrollPhysics();
	}

	@override
	bool shouldNotify(TestScrollBehavior old) => flag != old.flag;

	@override
	GestureVelocityTrackerBuilder velocityTrackerBuilder(BuildContext context) {
	lastCreatedBuilder = flag
	? (PointerEvent ev) => VelocityTracker.withKind(ev.kind)
	: (PointerEvent ev) => IOSScrollViewFlingVelocityTracker(ev.kind);
	return lastCreatedBuilder;
	}
	}

	void main() {
	testWidgets('Assert in buildScrollbar that controller != null when using it', (WidgetTester tester) async {
	const ScrollBehavior defaultBehavior = ScrollBehavior();
	late BuildContext capturedContext;

	await tester.pumpWidget(ScrollConfiguration(
	// Avoid the default ones here.
	behavior: const ScrollBehavior().copyWith(scrollbars: false),
	child: SingleChildScrollView(
	child: Builder(
	builder: (BuildContext context) {
	capturedContext = context;
	return Container(height: 1000.0);
	},
	),
	),
	));

	const ScrollableDetails details = ScrollableDetails(direction: AxisDirection.down);
	final Widget child = Container();

	switch (defaultTargetPlatform) {
	case TargetPlatform.android:
	case TargetPlatform.fuchsia:
	case TargetPlatform.iOS:
	// Does not throw if we aren't using it.
	defaultBehavior.buildScrollbar(capturedContext, child, details);
	case TargetPlatform.linux:
	case TargetPlatform.macOS:
	case TargetPlatform.windows:
	expect(
	() {
	defaultBehavior.buildScrollbar(capturedContext, child, details);
	},
	throwsA(
	isA<AssertionError>().having((AssertionError error) => error.toString(),
	'description', contains('details.controller != null')),
	),
	);
	}
	}, variant: TargetPlatformVariant.all());

	// Regression test for https://github.com/flutter/flutter/issues/89681
	testWidgets('_WrappedScrollBehavior shouldNotify test', (WidgetTester tester) async {
	final ScrollBehavior behavior1 = const ScrollBehavior().copyWith();
	final ScrollBehavior behavior2 = const ScrollBehavior().copyWith();

	expect(behavior1.shouldNotify(behavior2), false);
	});

	testWidgets('Inherited ScrollConfiguration changed', (WidgetTester tester) async {
	final GlobalKey key = GlobalKey(debugLabel: 'scrollable');
	TestScrollBehavior? behavior;
	late ScrollPositionWithSingleContext position;

	final Widget scrollView = SingleChildScrollView(
	key: key,
	child: Builder(
	builder: (BuildContext context) {
	behavior = ScrollConfiguration.of(context) as TestScrollBehavior;
	position = Scrollable.of(context).position as ScrollPositionWithSingleContext;
	return Container(height: 1000.0);
	},
	),
	);

	await tester.pumpWidget(
	ScrollConfiguration(
	behavior: const TestScrollBehavior(true),
	child: scrollView,
	),
	);

	expect(behavior, isNotNull);
	expect(behavior!.flag, isTrue);
	expect(position.physics, isA<ClampingScrollPhysics>());
	expect(lastCreatedBuilder(const PointerDownEvent()), isA<VelocityTracker>());
	ScrollMetrics metrics = position.copyWith();
	expect(metrics.extentAfter, equals(400.0));
	expect(metrics.viewportDimension, equals(600.0));

	// Same Scrollable, different ScrollConfiguration
	await tester.pumpWidget(
	ScrollConfiguration(
	behavior: const TestScrollBehavior(false),
	child: scrollView,
	),
	);

	expect(behavior, isNotNull);
	expect(behavior!.flag, isFalse);
	expect(position.physics, isA<BouncingScrollPhysics>());
	expect(lastCreatedBuilder(const PointerDownEvent()), isA<IOSScrollViewFlingVelocityTracker>());
	// Regression test for https://github.com/flutter/flutter/issues/5856
	metrics = position.copyWith();
	expect(metrics.extentAfter, equals(400.0));
	expect(metrics.viewportDimension, equals(600.0));
	});

	testWidgets('ScrollBehavior default android overscroll indicator', (WidgetTester tester) async {
	await tester.pumpWidget(
	Directionality(
	textDirection: TextDirection.ltr,
	child: ScrollConfiguration(
	behavior: const ScrollBehavior(),
	child: ListView(
	children: const <Widget>[
	SizedBox(
	height: 1000.0,
	width: 1000.0,
	child: Text('Test'),
	),
	],
	),
	),
	),
	);

	expect(find.byType(StretchingOverscrollIndicator), findsNothing);
	expect(find.byType(GlowingOverscrollIndicator), findsOneWidget);
	}, variant: TargetPlatformVariant.only(TargetPlatform.android));

	testWidgets('ScrollBehavior multitouchDragStrategy test - 1', (WidgetTester tester) async {
	const ScrollBehavior behavior1 = ScrollBehavior();
	final ScrollBehavior behavior2 = const ScrollBehavior().copyWith(
	multitouchDragStrategy: MultitouchDragStrategy.sumAllPointers
	);
	final ScrollController controller = ScrollController();
	addTearDown(() => controller.dispose());

	Widget buildFrame(ScrollBehavior behavior) {
	return Directionality(
	textDirection: TextDirection.ltr,
	child: ScrollConfiguration(
	behavior: behavior,
	child: ListView(
	controller: controller,
	children: const <Widget>[
	SizedBox(
	height: 1000.0,
	width: 1000.0,
	child: Text('I Love Flutter!'),
	),
	],
	),
	),
	);
	}

	await tester.pumpWidget(buildFrame(behavior1));

	expect(controller.position.pixels, 0.0);

	final Offset listLocation = tester.getCenter(find.byType(ListView));

	final TestGesture gesture1 = await tester.createGesture(pointer: 1);
	await gesture1.down(listLocation);
	await tester.pump();

	final TestGesture gesture2 = await tester.createGesture(pointer: 2);
	await gesture2.down(listLocation);
	await tester.pump();

	await gesture1.moveBy(const Offset(0, -50));
	await tester.pump();

	await gesture2.moveBy(const Offset(0, -50));
	await tester.pump();

	// The default multitouchDragStrategy is 'latestPointer' or 'averageBoundaryPointers,
	// the received delta should be 50.0.
	expect(controller.position.pixels, 50.0);

	// Change to sumAllPointers.
	await tester.pumpWidget(buildFrame(behavior2));

	await gesture1.moveBy(const Offset(0, -50));
	await tester.pump();

	await gesture2.moveBy(const Offset(0, -50));
	await tester.pump();

	// All active pointers be tracked.
	expect(controller.position.pixels, 50.0 + 50.0 + 50.0);
	}, variant: TargetPlatformVariant.all());

	testWidgets('ScrollBehavior multitouchDragStrategy test (non-Apple platforms) - 2', (WidgetTester tester) async {
	const ScrollBehavior behavior1 = ScrollBehavior();
	final ScrollBehavior behavior2 = const ScrollBehavior().copyWith(
	multitouchDragStrategy: MultitouchDragStrategy.averageBoundaryPointers
	);
	final ScrollController controller = ScrollController();
	late BuildContext capturedContext;
	addTearDown(() => controller.dispose());

	Widget buildFrame(ScrollBehavior behavior) {
	return Directionality(
	textDirection: TextDirection.ltr,
	child: ScrollConfiguration(
	behavior: behavior,
	child: Builder(
	builder: (BuildContext context) {
	capturedContext = context;
	return ListView(
	controller: controller,
	children: const <Widget>[
	SizedBox(
	height: 1000.0,
	width: 1000.0,
	child: Text('I Love Flutter!'),
	),
	],
	);
	},
	),
	),
	);
	}

	await tester.pumpWidget(buildFrame(behavior1));

	expect(controller.position.pixels, 0.0);

	final Offset listLocation = tester.getCenter(find.byType(ListView));

	final TestGesture gesture1 = await tester.createGesture(pointer: 1);
	await gesture1.down(listLocation);
	await tester.pump();

	final TestGesture gesture2 = await tester.createGesture(pointer: 2);
	await gesture2.down(listLocation);
	await tester.pump();

	await gesture1.moveBy(const Offset(0, -50));
	await tester.pump();

	await gesture2.moveBy(const Offset(0, -40));
	await tester.pump();

	// The default multitouchDragStrategy is latestPointer.
	// Only the latest active pointer be tracked.
	final ScrollBehavior scrollBehavior = ScrollConfiguration.of(capturedContext);
	expect(scrollBehavior.getMultitouchDragStrategy(capturedContext), MultitouchDragStrategy.latestPointer);
	expect(controller.position.pixels, 40.0);

	// Change to averageBoundaryPointers.
	await tester.pumpWidget(buildFrame(behavior2));

	await gesture1.moveBy(const Offset(0, -70));
	await tester.pump();

	await gesture2.moveBy(const Offset(0, -60));
	await tester.pump();

	expect(controller.position.pixels, 40.0 + 70.0);
	}, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.android, TargetPlatform.linux, TargetPlatform.fuchsia, TargetPlatform.windows }));

	testWidgets('ScrollBehavior multitouchDragStrategy test (Apple platforms) - 3', (WidgetTester tester) async {
	const ScrollBehavior behavior1 = ScrollBehavior();
	final ScrollBehavior behavior2 = const ScrollBehavior().copyWith(
	multitouchDragStrategy: MultitouchDragStrategy.latestPointer
	);
	final ScrollController controller = ScrollController();
	late BuildContext capturedContext;
	addTearDown(() => controller.dispose());

	Widget buildFrame(ScrollBehavior behavior) {
	return Directionality(
	textDirection: TextDirection.ltr,
	child: ScrollConfiguration(
	behavior: behavior,
	child: Builder(
	builder: (BuildContext context) {
	capturedContext = context;
	return ListView(
	controller: controller,
	children: const <Widget>[
	SizedBox(
	height: 1000.0,
	width: 1000.0,
	child: Text('I Love Flutter!'),
	),
	],
	);
	},
	),
	),
	);
	}

	await tester.pumpWidget(buildFrame(behavior1));

	expect(controller.position.pixels, 0.0);

	final Offset listLocation = tester.getCenter(find.byType(ListView));

	final TestGesture gesture1 = await tester.createGesture(pointer: 1);
	await gesture1.down(listLocation);
	await tester.pump();

	final TestGesture gesture2 = await tester.createGesture(pointer: 2);
	await gesture2.down(listLocation);
	await tester.pump();

	await gesture1.moveBy(const Offset(0, -40));
	await tester.pump();

	await gesture2.moveBy(const Offset(0, -50));
	await tester.pump();

	// The default multitouchDragStrategy is averageBoundaryPointers.
	final ScrollBehavior scrollBehavior = ScrollConfiguration.of(capturedContext);
	expect(scrollBehavior.getMultitouchDragStrategy(capturedContext), MultitouchDragStrategy.averageBoundaryPointers);
	expect(controller.position.pixels, 50.0);

	// Change to latestPointer.
	await tester.pumpWidget(buildFrame(behavior2));

	await gesture1.moveBy(const Offset(0, -50));
	await tester.pump();

	await gesture2.moveBy(const Offset(0, -40));
	await tester.pump();

	expect(controller.position.pixels, 50.0 + 40.0);
	}, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS, TargetPlatform.macOS }));

	group('ScrollBehavior configuration is maintained over multiple copies', () {
	testWidgets('dragDevices', (WidgetTester tester) async {
	// Regression test for https://github.com/flutter/flutter/issues/91673
	const ScrollBehavior defaultBehavior = ScrollBehavior();
	expect(defaultBehavior.dragDevices, <PointerDeviceKind>{
	PointerDeviceKind.touch,
	PointerDeviceKind.stylus,
	PointerDeviceKind.invertedStylus,
	PointerDeviceKind.trackpad,
	PointerDeviceKind.unknown,
	});

	// Use copyWith to modify drag devices
	final ScrollBehavior onceCopiedBehavior = defaultBehavior.copyWith(
	dragDevices: PointerDeviceKind.values.toSet(),
	);
	expect(onceCopiedBehavior.dragDevices, PointerDeviceKind.values.toSet());

	// Copy again. The previously modified drag devices should carry over.
	final ScrollBehavior twiceCopiedBehavior = onceCopiedBehavior.copyWith();
	expect(twiceCopiedBehavior.dragDevices, PointerDeviceKind.values.toSet());
	});

	testWidgets('physics', (WidgetTester tester) async {
	// Regression test for https://github.com/flutter/flutter/issues/91673
	late ScrollPhysics defaultPhysics;
	late ScrollPhysics onceCopiedPhysics;
	late ScrollPhysics twiceCopiedPhysics;

	await tester.pumpWidget(ScrollConfiguration(
	// Default ScrollBehavior
	behavior: const ScrollBehavior(),
	child: Builder(
	builder: (BuildContext context) {
	final ScrollBehavior defaultBehavior = ScrollConfiguration.of(context);
	// Copy once to change physics
	defaultPhysics = defaultBehavior.getScrollPhysics(context);
	return ScrollConfiguration(
	behavior: defaultBehavior.copyWith(physics: const BouncingScrollPhysics()),
	child: Builder(
	builder: (BuildContext context) {
	final ScrollBehavior onceCopiedBehavior = ScrollConfiguration.of(context);
	onceCopiedPhysics = onceCopiedBehavior.getScrollPhysics(context);
	return ScrollConfiguration(
	// Copy again, physics should follow
	behavior: onceCopiedBehavior.copyWith(),
	child: Builder(
	builder: (BuildContext context) {
	twiceCopiedPhysics = ScrollConfiguration.of(context).getScrollPhysics(context);
	return SingleChildScrollView(child: Container(height: 1000));
	}
	)
	);
	}
	)
	);
	}
	),
	));

	expect(defaultPhysics, const ClampingScrollPhysics(parent: RangeMaintainingScrollPhysics()));
	expect(onceCopiedPhysics, const BouncingScrollPhysics());
	expect(twiceCopiedPhysics, const BouncingScrollPhysics());
	});

	testWidgets('platform', (WidgetTester tester) async {
	// Regression test for https://github.com/flutter/flutter/issues/91673
	late TargetPlatform defaultPlatform;
	late TargetPlatform onceCopiedPlatform;
	late TargetPlatform twiceCopiedPlatform;

	await tester.pumpWidget(ScrollConfiguration(
	// Default ScrollBehavior
	behavior: const ScrollBehavior(),
	child: Builder(
	builder: (BuildContext context) {
	final ScrollBehavior defaultBehavior = ScrollConfiguration.of(context);
	// Copy once to change physics
	defaultPlatform = defaultBehavior.getPlatform(context);
	return ScrollConfiguration(
	behavior: defaultBehavior.copyWith(platform: TargetPlatform.fuchsia),
	child: Builder(
	builder: (BuildContext context) {
	final ScrollBehavior onceCopiedBehavior = ScrollConfiguration.of(context);
	onceCopiedPlatform = onceCopiedBehavior.getPlatform(context);
	return ScrollConfiguration(
	// Copy again, physics should follow
	behavior: onceCopiedBehavior.copyWith(),
	child: Builder(
	builder: (BuildContext context) {
	twiceCopiedPlatform = ScrollConfiguration.of(context).getPlatform(context);
	return SingleChildScrollView(child: Container(height: 1000));
	}
	)
	);
	}
	)
	);
	}
	),
	));

	expect(defaultPlatform, TargetPlatform.android);
	expect(onceCopiedPlatform, TargetPlatform.fuchsia);
	expect(twiceCopiedPlatform, TargetPlatform.fuchsia);
	});

	Widget wrap(ScrollBehavior behavior) {
	return Directionality(
	textDirection: TextDirection.ltr,
	child: MediaQuery(
	data: const MediaQueryData(size: Size(500, 500)),
	child: ScrollConfiguration(
	behavior: behavior,
	child: Builder(
	builder: (BuildContext context) => SingleChildScrollView(child: Container(height: 1000))
	)
	),
	)
	);
	}

	testWidgets('scrollbar', (WidgetTester tester) async {
	// Regression test for https://github.com/flutter/flutter/issues/91673
	const ScrollBehavior defaultBehavior = ScrollBehavior();
	await tester.pumpWidget(wrap(defaultBehavior));
	// Default adds a scrollbar
	expect(find.byType(RawScrollbar), findsOneWidget);
	final ScrollBehavior onceCopiedBehavior = defaultBehavior.copyWith(scrollbars: false);

	await tester.pumpWidget(wrap(onceCopiedBehavior));
	// Copy does not add scrollbar
	expect(find.byType(RawScrollbar), findsNothing);
	final ScrollBehavior twiceCopiedBehavior = onceCopiedBehavior.copyWith();

	await tester.pumpWidget(wrap(twiceCopiedBehavior));
	// Second copy maintains scrollbar setting
	expect(find.byType(RawScrollbar), findsNothing);

	// For default scrollbars
	}, variant: TargetPlatformVariant.desktop());

	testWidgets('overscroll', (WidgetTester tester) async {
	// Regression test for https://github.com/flutter/flutter/issues/91673
	const ScrollBehavior defaultBehavior = ScrollBehavior();
	await tester.pumpWidget(wrap(defaultBehavior));
	// Default adds a glowing overscroll indicator
	expect(find.byType(GlowingOverscrollIndicator), findsOneWidget);
	final ScrollBehavior onceCopiedBehavior = defaultBehavior.copyWith(overscroll: false);

	await tester.pumpWidget(wrap(onceCopiedBehavior));
	// Copy does not add indicator
	expect(find.byType(GlowingOverscrollIndicator), findsNothing);
	final ScrollBehavior twiceCopiedBehavior = onceCopiedBehavior.copyWith();

	await tester.pumpWidget(wrap(twiceCopiedBehavior));
	// Second copy maintains overscroll setting
	expect(find.byType(GlowingOverscrollIndicator), findsNothing);

	// For default glowing indicator
	}, variant: TargetPlatformVariant.only(TargetPlatform.android));
	});
	}