Eliminate rebuilds for Scaffold FAB animation by nate-thegrate · Pull Request #182331 · flutter/flutter

nate-thegrate · 2026-02-12T23:44:17Z

This PR contains a tweak to the Scaffold widget's internal logic, reducing the amount of work that needs to be performed each time the FAB animation updates.

resolves #182330

gemini-code-assist

Code Review

This pull request optimizes the Scaffold widget to prevent unnecessary rebuilds during the Floating Action Button (FAB) animation. The change replaces an AnimatedBuilder with a Builder and passes the FAB's move animation controller directly to the _ScaffoldLayout delegate's relayout property. This ensures that only the layout is updated when the animation ticks, rather than rebuilding a larger portion of the widget tree. A new test has been added to confirm that the widget building the CustomMultiChildLayout is not marked as dirty during the animation, verifying the performance improvement.

dkwingsmt

LGTM. Thank you!

dkwingsmt · 2026-02-25T19:28:30Z

    expect(find.byType(FloatingActionButton), findsNothing);
  });

+  testWidgets('Scaffold FAB animates without rebuilding', (WidgetTester tester) async {


Do we have a test to verify that the animation is indeed applied (i.e. relayout: is correctly assigned)?

Yes we do! I was able to find two tests that cover the FAB animation:

flutter/packages/flutter/test/material/scaffold_test.dart

Lines 318 to 366 in d9556bd

testWidgets('Floating action entrance/exit animation', (WidgetTester tester) async {

await tester.pumpWidget(

const MaterialApp(

home: Scaffold(

floatingActionButton: FloatingActionButton(

key: Key('one'),

onPressed: null,

child: Text('1'),

),

),

),

);

expect(tester.binding.transientCallbackCount, 0);

await tester.pumpWidget(

const MaterialApp(

home: Scaffold(

floatingActionButton: FloatingActionButton(

key: Key('two'),

onPressed: null,

child: Text('2'),

),

),

),

);

expect(tester.binding.transientCallbackCount, greaterThan(0));

await tester.pumpWidget(Container());

expect(tester.binding.transientCallbackCount, 0);

await tester.pumpWidget(const MaterialApp(home: Scaffold()));

expect(tester.binding.transientCallbackCount, 0);

await tester.pumpWidget(

const MaterialApp(

home: Scaffold(

floatingActionButton: FloatingActionButton(

key: Key('one'),

onPressed: null,

child: Text('1'),

),

),

),

);

expect(tester.binding.transientCallbackCount, greaterThan(0));

});

flutter/packages/flutter/test/material/scaffold_test.dart

Lines 3553 to 3606 in d9556bd

testWidgets('FAB default entrance and exit animations', (WidgetTester tester) async {

var showFab = false;

await tester.pumpWidget(

MaterialApp(

home: StatefulBuilder(

builder: (BuildContext context, StateSetter setState) {

return Scaffold(

body: ElevatedButton(

onPressed: () {

setState(() {

showFab = !showFab;

});

},

child: const Text('Toggle FAB'),

),

floatingActionButton: !showFab

? null

: FloatingActionButton(onPressed: () {}, child: const Icon(Icons.add)),

);

},

),

),

);

// FAB is not visible.

expect(find.byType(FloatingActionButton), findsNothing);

// Tap the button to show the FAB.

await tester.tap(find.widgetWithText(ElevatedButton, 'Toggle FAB'));

await tester.pump();

await tester.pump(const Duration(milliseconds: 100)); // Advance the animation by 100ms.

// FAB is partially animated in.

expect(tester.getTopLeft(find.byType(FloatingActionButton)).dx, closeTo(743.8, 0.1));

await tester.pump(const Duration(milliseconds: 100)); // Advance the animation by 100ms.

// FAB is fully animated in.

expect(tester.getTopLeft(find.byType(FloatingActionButton)).dx, equals(728.0));

// Tap the button to hide the FAB.

await tester.tap(find.widgetWithText(ElevatedButton, 'Toggle FAB'));

await tester.pump();

await tester.pump(const Duration(milliseconds: 100)); // Advance the animation by 100ms.

// FAB is partially animated out.

expect(tester.getTopLeft(find.byType(FloatingActionButton)).dx, closeTo(747.1, 0.1));

await tester.pump(const Duration(milliseconds: 100)); // Advance the animation by 100ms.

// FAB is fully animated out.

expect(tester.getTopLeft(find.byType(FloatingActionButton)).dx, equals(756.0));

await tester.pump(const Duration(milliseconds: 50)); // Advance the animation by 50ms.

// FAB is not visible.

expect(find.byType(FloatingActionButton), findsNothing);

});

justinmc

LGTM 👍 Good catch!

auto-submit · 2026-02-26T19:49:26Z

autosubmit label was removed for flutter/flutter/182331, because - The status or check suite Google testing has failed. Please fix the issues identified (or deflake) before re-applying this label.

nate-thegrate · 2026-02-26T20:49:37Z

Dang it, looks like Google Testing failed. I'll re-trigger the checks in hopes that it was a flake…

nate-thegrate · 2026-02-26T22:03:38Z

Everything passed! I believe we are ready to land 🫡

…ter#182331)

Roll Flutter from d3dd7744e81f to d18214307703 (33 revisions) flutter/flutter@d3dd774...d182143 2026-03-06 [email protected] Roll Packages from 8d5c5cd to fe3de64 (2 revisions) (flutter/flutter#183308) 2026-03-06 [email protected] Roll Dart SDK from 1b51451cdb99 to 7c7c1e3d024d (2 revisions) (flutter/flutter#183294) 2026-03-06 [email protected] Roll Dart SDK from 9ac06cdd1801 to 1b51451cdb99 (9 revisions) (flutter/flutter#183289) 2026-03-06 [email protected] Add GitHub workflows to assist with release tasks (flutter/flutter#181978) 2026-03-06 [email protected] [Impeller] Fix new convex path shadow generation in perspective (flutter/flutter#183187) 2026-03-06 [email protected] Roll pub packages (flutter/flutter#183178) 2026-03-05 [email protected] fix: use double quotes in settings.gradle.kts template (flutter/flutter#183081) 2026-03-05 [email protected] Add fallbackColor for PredictiveBackPageTransitionBuilder and PredictiveBackFullscreenPageTransitionBuilder (flutter/flutter#182690) 2026-03-05 [email protected] Simplify TesterContextGLES (multithreading logic not needed), and enable some tests that now pass (flutter/flutter#183250) 2026-03-05 [email protected] Roll Skia from a94df1cdabb0 to a69ef43650ee (14 revisions) (flutter/flutter#183280) 2026-03-05 [email protected] Windowing implementation of `showDialog` that uses a native desktop window to display the content (flutter/flutter#181861) 2026-03-05 [email protected] Build CocoaPod plugin frameworks for Add to App FlutterPluginRegistrant (flutter/flutter#183239) 2026-03-05 [email protected] Extend the Linux web_skwasm_tests_1 timeout to 45 minutes (flutter/flutter#183247) 2026-03-05 [email protected] Update Dart to 3.12 beta 2 (flutter/flutter#183251) 2026-03-05 [email protected] Replace the rest of the references to `flutter/engine` with `flutter/flutter` (flutter/flutter#182938) 2026-03-05 [email protected] chore: convert android_verified_input to pub-workspace (flutter/flutter#183175) 2026-03-05 [email protected] Add await to flutter_test callsites (flutter/flutter#182983) 2026-03-05 [email protected] [iOS] Skip gesture recognizer reset workaround on iOS 26+ (flutter/flutter#183186) 2026-03-05 [email protected] Add warning for plugins not migrated to UIScene (flutter/flutter#182826) 2026-03-05 [email protected] Roll Fuchsia Linux SDK from JJw5EJ87vLGqFVl4h... to 8ay15_eQOEgPHCypm... (flutter/flutter#183255) 2026-03-05 [email protected] Roll Skia from ada0b7628c79 to a94df1cdabb0 (2 revisions) (flutter/flutter#183249) 2026-03-05 [email protected] Roll Packages from 82baf93 to 8d5c5cd (2 revisions) (flutter/flutter#183269) 2026-03-05 [email protected] Add `UnlabaledLeafNodeEvaluation` (flutter/flutter#182872) 2026-03-04 [email protected] Re-specify the ndk version in various test apps, to prevent ndk download (flutter/flutter#183134) 2026-03-04 [email protected] Eliminate rebuilds for Scaffold FAB animation (flutter/flutter#182331) 2026-03-04 [email protected] Add Michal Kucharski to AUTHORS (flutter/flutter#182366) 2026-03-04 [email protected] Merge changelog from 3.41.4 stable. (flutter/flutter#183243) 2026-03-04 [email protected] Allow stylus support on windows (flutter/flutter#165323) 2026-03-04 [email protected] Fix docs on SingletonFlutterWindow.supportsShowingSystemContextMenu (flutter/flutter#183142) 2026-03-04 [email protected] Roll Packages from 9083bc9 to 82baf93 (5 revisions) (flutter/flutter#183240) 2026-03-04 [email protected] Fixes FocusHighlightMode on Android when typing in software keyboard (flutter/flutter#180753) 2026-03-04 [email protected] Make compileShader() retry without sksl if it fails with sksl. (flutter/flutter#183146) 2026-03-04 [email protected] [web] Use pointer-events: auto for non-interactive leaf semantics nodes (flutter/flutter#183077) If this roll has caused a breakage, revert this CL and stop the roller using the controls here: https://autoroll.skia.org/r/flutter-packages Please CC [email protected],[email protected] on the revert to ensure that a human is aware of the problem. To file a bug in Packages: https://github.com/flutter/flutter/issues/new/choose To report a problem with the AutoRoller itself, please file a bug: https://issues.skia.org/issues/new?component=1389291&template=1850622 Documentation for the AutoRoller is here: ...

This PR contains a tweak to the Scaffold widget's internal logic, reducing the amount of work that needs to be performed each time the FAB animation updates. resolves flutter#182330

…r#11191) Roll Flutter from d3dd7744e81f to d18214307703 (33 revisions) flutter/flutter@d3dd774...d182143 2026-03-06 [email protected] Roll Packages from 8d5c5cd to fe3de64 (2 revisions) (flutter/flutter#183308) 2026-03-06 [email protected] Roll Dart SDK from 1b51451cdb99 to 7c7c1e3d024d (2 revisions) (flutter/flutter#183294) 2026-03-06 [email protected] Roll Dart SDK from 9ac06cdd1801 to 1b51451cdb99 (9 revisions) (flutter/flutter#183289) 2026-03-06 [email protected] Add GitHub workflows to assist with release tasks (flutter/flutter#181978) 2026-03-06 [email protected] [Impeller] Fix new convex path shadow generation in perspective (flutter/flutter#183187) 2026-03-06 [email protected] Roll pub packages (flutter/flutter#183178) 2026-03-05 [email protected] fix: use double quotes in settings.gradle.kts template (flutter/flutter#183081) 2026-03-05 [email protected] Add fallbackColor for PredictiveBackPageTransitionBuilder and PredictiveBackFullscreenPageTransitionBuilder (flutter/flutter#182690) 2026-03-05 [email protected] Simplify TesterContextGLES (multithreading logic not needed), and enable some tests that now pass (flutter/flutter#183250) 2026-03-05 [email protected] Roll Skia from a94df1cdabb0 to a69ef43650ee (14 revisions) (flutter/flutter#183280) 2026-03-05 [email protected] Windowing implementation of `showDialog` that uses a native desktop window to display the content (flutter/flutter#181861) 2026-03-05 [email protected] Build CocoaPod plugin frameworks for Add to App FlutterPluginRegistrant (flutter/flutter#183239) 2026-03-05 [email protected] Extend the Linux web_skwasm_tests_1 timeout to 45 minutes (flutter/flutter#183247) 2026-03-05 [email protected] Update Dart to 3.12 beta 2 (flutter/flutter#183251) 2026-03-05 [email protected] Replace the rest of the references to `flutter/engine` with `flutter/flutter` (flutter/flutter#182938) 2026-03-05 [email protected] chore: convert android_verified_input to pub-workspace (flutter/flutter#183175) 2026-03-05 [email protected] Add await to flutter_test callsites (flutter/flutter#182983) 2026-03-05 [email protected] [iOS] Skip gesture recognizer reset workaround on iOS 26+ (flutter/flutter#183186) 2026-03-05 [email protected] Add warning for plugins not migrated to UIScene (flutter/flutter#182826) 2026-03-05 [email protected] Roll Fuchsia Linux SDK from JJw5EJ87vLGqFVl4h... to 8ay15_eQOEgPHCypm... (flutter/flutter#183255) 2026-03-05 [email protected] Roll Skia from ada0b7628c79 to a94df1cdabb0 (2 revisions) (flutter/flutter#183249) 2026-03-05 [email protected] Roll Packages from 82baf93 to 8d5c5cd (2 revisions) (flutter/flutter#183269) 2026-03-05 [email protected] Add `UnlabaledLeafNodeEvaluation` (flutter/flutter#182872) 2026-03-04 [email protected] Re-specify the ndk version in various test apps, to prevent ndk download (flutter/flutter#183134) 2026-03-04 [email protected] Eliminate rebuilds for Scaffold FAB animation (flutter/flutter#182331) 2026-03-04 [email protected] Add Michal Kucharski to AUTHORS (flutter/flutter#182366) 2026-03-04 [email protected] Merge changelog from 3.41.4 stable. (flutter/flutter#183243) 2026-03-04 [email protected] Allow stylus support on windows (flutter/flutter#165323) 2026-03-04 [email protected] Fix docs on SingletonFlutterWindow.supportsShowingSystemContextMenu (flutter/flutter#183142) 2026-03-04 [email protected] Roll Packages from 9083bc9 to 82baf93 (5 revisions) (flutter/flutter#183240) 2026-03-04 [email protected] Fixes FocusHighlightMode on Android when typing in software keyboard (flutter/flutter#180753) 2026-03-04 [email protected] Make compileShader() retry without sksl if it fails with sksl. (flutter/flutter#183146) 2026-03-04 [email protected] [web] Use pointer-events: auto for non-interactive leaf semantics nodes (flutter/flutter#183077) If this roll has caused a breakage, revert this CL and stop the roller using the controls here: https://autoroll.skia.org/r/flutter-packages Please CC [email protected],[email protected] on the revert to ensure that a human is aware of the problem. To file a bug in Packages: https://github.com/flutter/flutter/issues/new/choose To report a problem with the AutoRoller itself, please file a bug: https://issues.skia.org/issues/new?component=1389291&template=1850622 Documentation for the AutoRoller is here: ...

This PR contains a tweak to the Scaffold widget's internal logic, reducing the amount of work that needs to be performed each time the FAB animation updates. resolves flutter#182330

…r#11191) Roll Flutter from d3dd7744e81f to d18214307703 (33 revisions) flutter/flutter@d3dd774...d182143 2026-03-06 [email protected] Roll Packages from 8d5c5cd to fe3de64 (2 revisions) (flutter/flutter#183308) 2026-03-06 [email protected] Roll Dart SDK from 1b51451cdb99 to 7c7c1e3d024d (2 revisions) (flutter/flutter#183294) 2026-03-06 [email protected] Roll Dart SDK from 9ac06cdd1801 to 1b51451cdb99 (9 revisions) (flutter/flutter#183289) 2026-03-06 [email protected] Add GitHub workflows to assist with release tasks (flutter/flutter#181978) 2026-03-06 [email protected] [Impeller] Fix new convex path shadow generation in perspective (flutter/flutter#183187) 2026-03-06 [email protected] Roll pub packages (flutter/flutter#183178) 2026-03-05 [email protected] fix: use double quotes in settings.gradle.kts template (flutter/flutter#183081) 2026-03-05 [email protected] Add fallbackColor for PredictiveBackPageTransitionBuilder and PredictiveBackFullscreenPageTransitionBuilder (flutter/flutter#182690) 2026-03-05 [email protected] Simplify TesterContextGLES (multithreading logic not needed), and enable some tests that now pass (flutter/flutter#183250) 2026-03-05 [email protected] Roll Skia from a94df1cdabb0 to a69ef43650ee (14 revisions) (flutter/flutter#183280) 2026-03-05 [email protected] Windowing implementation of `showDialog` that uses a native desktop window to display the content (flutter/flutter#181861) 2026-03-05 [email protected] Build CocoaPod plugin frameworks for Add to App FlutterPluginRegistrant (flutter/flutter#183239) 2026-03-05 [email protected] Extend the Linux web_skwasm_tests_1 timeout to 45 minutes (flutter/flutter#183247) 2026-03-05 [email protected] Update Dart to 3.12 beta 2 (flutter/flutter#183251) 2026-03-05 [email protected] Replace the rest of the references to `flutter/engine` with `flutter/flutter` (flutter/flutter#182938) 2026-03-05 [email protected] chore: convert android_verified_input to pub-workspace (flutter/flutter#183175) 2026-03-05 [email protected] Add await to flutter_test callsites (flutter/flutter#182983) 2026-03-05 [email protected] [iOS] Skip gesture recognizer reset workaround on iOS 26+ (flutter/flutter#183186) 2026-03-05 [email protected] Add warning for plugins not migrated to UIScene (flutter/flutter#182826) 2026-03-05 [email protected] Roll Fuchsia Linux SDK from JJw5EJ87vLGqFVl4h... to 8ay15_eQOEgPHCypm... (flutter/flutter#183255) 2026-03-05 [email protected] Roll Skia from ada0b7628c79 to a94df1cdabb0 (2 revisions) (flutter/flutter#183249) 2026-03-05 [email protected] Roll Packages from 82baf93 to 8d5c5cd (2 revisions) (flutter/flutter#183269) 2026-03-05 [email protected] Add `UnlabaledLeafNodeEvaluation` (flutter/flutter#182872) 2026-03-04 [email protected] Re-specify the ndk version in various test apps, to prevent ndk download (flutter/flutter#183134) 2026-03-04 [email protected] Eliminate rebuilds for Scaffold FAB animation (flutter/flutter#182331) 2026-03-04 [email protected] Add Michal Kucharski to AUTHORS (flutter/flutter#182366) 2026-03-04 [email protected] Merge changelog from 3.41.4 stable. (flutter/flutter#183243) 2026-03-04 [email protected] Allow stylus support on windows (flutter/flutter#165323) 2026-03-04 [email protected] Fix docs on SingletonFlutterWindow.supportsShowingSystemContextMenu (flutter/flutter#183142) 2026-03-04 [email protected] Roll Packages from 9083bc9 to 82baf93 (5 revisions) (flutter/flutter#183240) 2026-03-04 [email protected] Fixes FocusHighlightMode on Android when typing in software keyboard (flutter/flutter#180753) 2026-03-04 [email protected] Make compileShader() retry without sksl if it fails with sksl. (flutter/flutter#183146) 2026-03-04 [email protected] [web] Use pointer-events: auto for non-interactive leaf semantics nodes (flutter/flutter#183077) If this roll has caused a breakage, revert this CL and stop the roller using the controls here: https://autoroll.skia.org/r/flutter-packages Please CC [email protected],[email protected] on the revert to ensure that a human is aware of the problem. To file a bug in Packages: https://github.com/flutter/flutter/issues/new/choose To report a problem with the AutoRoller itself, please file a bug: https://issues.skia.org/issues/new?component=1389291&template=1850622 Documentation for the AutoRoller is here: ...

github-actions Bot added framework flutter/packages/flutter repository. See also f: labels. f: material design flutter/packages/flutter/material repository. labels Feb 12, 2026

gemini-code-assist Bot reviewed Feb 12, 2026

View reviewed changes

justinmc requested review from dkwingsmt and justinmc February 17, 2026 23:06

dkwingsmt approved these changes Feb 25, 2026

View reviewed changes

nate-thegrate force-pushed the optimized-fab branch 2 times, most recently from 8713055 to 9153a79 Compare February 26, 2026 17:16

justinmc approved these changes Feb 26, 2026

View reviewed changes

justinmc added the autosubmit Merge PR when tree becomes green via auto submit App label Feb 26, 2026

auto-submit Bot removed the autosubmit Merge PR when tree becomes green via auto submit App label Feb 26, 2026

nate-thegrate added 2 commits February 26, 2026 13:49

refactor FAB animation handling in ScaffoldLayout

5af5928

add test

11dfa06

nate-thegrate force-pushed the optimized-fab branch from 9153a79 to 11dfa06 Compare February 26, 2026 20:49

dkwingsmt added the autosubmit Merge PR when tree becomes green via auto submit App label Mar 4, 2026

auto-submit Bot added this pull request to the merge queue Mar 4, 2026

Merged via the queue into flutter:master with commit 9a78d7a Mar 4, 2026
73 of 74 checks passed

flutter-dashboard Bot removed the autosubmit Merge PR when tree becomes green via auto submit App label Mar 4, 2026

engine-flutter-autoroll mentioned this pull request Mar 5, 2026

Roll Flutter from 46fb7210422d to 308649c0cd1b (43 revisions) flutter/packages#11183

Closed

engine-flutter-autoroll added a commit to engine-flutter-autoroll/packages that referenced this pull request Mar 5, 2026

9a78d7a71 Eliminate rebuilds for Scaffold FAB animation (flutter/flut…

c36b489

…ter#182331)

engine-flutter-autoroll mentioned this pull request Mar 5, 2026

Roll Flutter from 46fb7210422d to 308649c0cd1b (43 revisions) flutter/packages#11184

Closed

engine-flutter-autoroll added a commit to engine-flutter-autoroll/packages that referenced this pull request Mar 5, 2026

9a78d7a71 Eliminate rebuilds for Scaffold FAB animation (flutter/flut…

bae83e9

…ter#182331)

engine-flutter-autoroll mentioned this pull request Mar 5, 2026

Roll Flutter from 46fb7210422d to 3c323fb06507 (44 revisions) flutter/packages#11186

Closed

engine-flutter-autoroll added a commit to engine-flutter-autoroll/packages that referenced this pull request Mar 5, 2026

9a78d7a71 Eliminate rebuilds for Scaffold FAB animation (flutter/flut…

59041f6

…ter#182331)

engine-flutter-autoroll mentioned this pull request Mar 5, 2026

Roll Flutter from 46fb7210422d to 1488fd4783de (45 revisions) flutter/packages#11187

Closed

engine-flutter-autoroll added a commit to engine-flutter-autoroll/packages that referenced this pull request Mar 5, 2026

9a78d7a71 Eliminate rebuilds for Scaffold FAB animation (flutter/flut…

bb1e1cd

…ter#182331)

engine-flutter-autoroll added a commit to engine-flutter-autoroll/packages that referenced this pull request Mar 6, 2026

9a78d7a71 Eliminate rebuilds for Scaffold FAB animation (flutter/flut…

b1c7729

…ter#182331)

engine-flutter-autoroll mentioned this pull request Mar 6, 2026

Roll Flutter from d3dd7744e81f to 7a95d24e493a (32 revisions) flutter/packages#11190

Closed

engine-flutter-autoroll added a commit to engine-flutter-autoroll/packages that referenced this pull request Mar 6, 2026

9a78d7a71 Eliminate rebuilds for Scaffold FAB animation (flutter/flut…

7bcbd1f

…ter#182331)

engine-flutter-autoroll mentioned this pull request Mar 6, 2026

Roll Flutter from d3dd7744e81f to d18214307703 (33 revisions) flutter/packages#11191

Merged

Piinks mentioned this pull request Mar 6, 2026

Flutter Notable Commits - 2026 #181433

Open

nate-thegrate deleted the optimized-fab branch March 7, 2026 03:10

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

Eliminate rebuilds for Scaffold FAB animation#182331

Eliminate rebuilds for Scaffold FAB animation#182331
auto-submit[bot] merged 2 commits into
flutter:masterfrom
nate-thegrate:optimized-fab

nate-thegrate commented Feb 12, 2026

Uh oh!

gemini-code-assist Bot left a comment

Uh oh!

dkwingsmt left a comment

Uh oh!

dkwingsmt Feb 25, 2026

Uh oh!

nate-thegrate Feb 26, 2026

Uh oh!

justinmc left a comment

Uh oh!

auto-submit Bot commented Feb 26, 2026

Uh oh!

nate-thegrate commented Feb 26, 2026

Uh oh!

nate-thegrate commented Feb 26, 2026

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

	testWidgets('Floating action entrance/exit animation', (WidgetTester tester) async {
	await tester.pumpWidget(
	const MaterialApp(
	home: Scaffold(
	floatingActionButton: FloatingActionButton(
	key: Key('one'),
	onPressed: null,
	child: Text('1'),
	),
	),
	),
	);

	expect(tester.binding.transientCallbackCount, 0);

	await tester.pumpWidget(
	const MaterialApp(
	home: Scaffold(
	floatingActionButton: FloatingActionButton(
	key: Key('two'),
	onPressed: null,
	child: Text('2'),
	),
	),
	),
	);

	expect(tester.binding.transientCallbackCount, greaterThan(0));
	await tester.pumpWidget(Container());
	expect(tester.binding.transientCallbackCount, 0);

	await tester.pumpWidget(const MaterialApp(home: Scaffold()));

	expect(tester.binding.transientCallbackCount, 0);

	await tester.pumpWidget(
	const MaterialApp(
	home: Scaffold(
	floatingActionButton: FloatingActionButton(
	key: Key('one'),
	onPressed: null,
	child: Text('1'),
	),
	),
	),
	);

	expect(tester.binding.transientCallbackCount, greaterThan(0));
	});

	testWidgets('FAB default entrance and exit animations', (WidgetTester tester) async {
	var showFab = false;

	await tester.pumpWidget(
	MaterialApp(
	home: StatefulBuilder(
	builder: (BuildContext context, StateSetter setState) {
	return Scaffold(
	body: ElevatedButton(
	onPressed: () {
	setState(() {
	showFab = !showFab;
	});
	},
	child: const Text('Toggle FAB'),
	),
	floatingActionButton: !showFab
	? null
	: FloatingActionButton(onPressed: () {}, child: const Icon(Icons.add)),
	);
	},
	),
	),
	);

	// FAB is not visible.
	expect(find.byType(FloatingActionButton), findsNothing);

	// Tap the button to show the FAB.
	await tester.tap(find.widgetWithText(ElevatedButton, 'Toggle FAB'));
	await tester.pump();
	await tester.pump(const Duration(milliseconds: 100)); // Advance the animation by 100ms.
	// FAB is partially animated in.
	expect(tester.getTopLeft(find.byType(FloatingActionButton)).dx, closeTo(743.8, 0.1));

	await tester.pump(const Duration(milliseconds: 100)); // Advance the animation by 100ms.
	// FAB is fully animated in.
	expect(tester.getTopLeft(find.byType(FloatingActionButton)).dx, equals(728.0));

	// Tap the button to hide the FAB.
	await tester.tap(find.widgetWithText(ElevatedButton, 'Toggle FAB'));
	await tester.pump();
	await tester.pump(const Duration(milliseconds: 100)); // Advance the animation by 100ms.
	// FAB is partially animated out.
	expect(tester.getTopLeft(find.byType(FloatingActionButton)).dx, closeTo(747.1, 0.1));

	await tester.pump(const Duration(milliseconds: 100)); // Advance the animation by 100ms.
	// FAB is fully animated out.
	expect(tester.getTopLeft(find.byType(FloatingActionButton)).dx, equals(756.0));

	await tester.pump(const Duration(milliseconds: 50)); // Advance the animation by 50ms.
	// FAB is not visible.
	expect(find.byType(FloatingActionButton), findsNothing);
	});

Uh oh!

Conversation

nate-thegrate commented Feb 12, 2026

Uh oh!

gemini-code-assist Bot left a comment

Choose a reason for hiding this comment

Code Review

Uh oh!

dkwingsmt left a comment

Choose a reason for hiding this comment

Uh oh!

dkwingsmt Feb 25, 2026

Choose a reason for hiding this comment

Uh oh!

nate-thegrate Feb 26, 2026

Choose a reason for hiding this comment

Uh oh!

justinmc left a comment

Choose a reason for hiding this comment

Uh oh!

auto-submit Bot commented Feb 26, 2026

Uh oh!

nate-thegrate commented Feb 26, 2026

Uh oh!

nate-thegrate commented Feb 26, 2026

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants