Repository navigation
Use reverseDuration for the AnimatedCrossFade size animation - #194860
Merged
auto-submit[bot] merged 5 commits intoNov 6, 2026
Merged
Conversation
github-actions
Bot
added
the
framework
![gemini-code-assist[bot]](https://avatars.githubusercontent.com/in/956858?s=60&v=4){kind=small}
Contributor
There was a problem hiding this comment.
Code Review
This pull request updates AnimatedCrossFade to use reverseDuration for the internal AnimatedSize when transitioning in the reverse direction, and adds tests to verify this behavior. The review feedback suggests checking _controller.status == AnimationStatus.reverse instead of _controller.isForwardOrCompleted to avoid asymmetric behavior during idle resizes of the first child, and recommends updating the corresponding test to assert this standard duration usage.
Member
|
LGTM! Nice catch. As a follow-up (outside of this PR), it looks like We should probably file an follow-up PR to deprecate |
11 tasks
victorsanni
reviewed
Oct 23, 2026
victorsanni
left a comment
victorsanni
left a comment
Contributor
There was a problem hiding this comment.
LGTM with some comments
Contributor
|
Hi, is this ready for re-review? Please remember to request a review if it is, so it gets back into the review queue. |
victorsanni
previously approved these changes
Nov 5, 2026
victorsanni
left a comment
victorsanni
left a comment
Contributor
There was a problem hiding this comment.
LGTM with comments.
Can you update the PR description with the latest state of the PR? And also documenting reverseDuration: Duration.zero still animating size over duration?
victorsanni
added
the
autosubmit
flutter-dashboard
Bot
removed
the
autosubmit
auto-submit Bot
pushed a commit
to flutter/packages
that referenced
this pull request
Nov 6, 2026
Roll Flutter from 3623d2d34543 to 09175cdeac89 (61 revisions) flutter/flutter@3623d2d...09175cd 2026-11-06 [email protected] Roll Skia from ae35b7b2221f to 793b8ac73d4b (3 revisions) (flutter/flutter#196091) 2026-11-06 [email protected] [web] Rasterize scenes at the size passed to `FlutterView.render` (flutter/flutter#196052) 2026-11-06 [email protected] Roll Skia from 4aa043a81e0c to ae35b7b2221f (1 revision) (flutter/flutter#196086) 2026-11-06 [email protected] Roll Fuchsia Linux SDK from Fqe3UlLwAohsPbsCS... to KIc0XZbhLmvDpTluZ... (flutter/flutter#196085) 2026-11-06 [email protected] Allow a zero scale change in InteractiveViewer (flutter/flutter#194949) 2026-11-06 [email protected] Roll Skia from dd5c2553a856 to 4aa043a81e0c (2 revisions) (flutter/flutter#196079) 2026-11-06 [email protected] [web] Keep ImageFilter.blur bounds in equality and description (flutter/flutter#196013) 2026-11-06 [email protected] iOS: Remove unused PlatformViewIOS setup from FlutterPlatformViewsTest (flutter/flutter#196033) 2026-11-06 [email protected] Serialize LoggerTests that mutate the shared Logger (flutter/flutter#196028) 2026-11-06 [email protected] Use reverseDuration for the AnimatedCrossFade size animation (flutter/flutter#194860) 2026-11-05 [email protected] Roll Skia from a5aacd103e68 to dd5c2553a856 (8 revisions) (flutter/flutter#196073) 2026-11-05 [email protected] Fix ListWheelScrollView null check error when it reads itemIndex before content dimensions are set (flutter/flutter#194859) 2026-11-05 [email protected] Allow zero cross axis extent in SliverGridDelegateWithMaxCrossAxisExtent (flutter/flutter#194858) 2026-11-05 [email protected] Revert: Allow color delta tolerance in in-memory fuzzy image comparator (flutter/flutter#196067) 2026-11-05 [email protected] Revert: Mitigate snapshot race in 3D transform test by reducing loop density (flutter/flutter#196066) 2026-11-05 [email protected] Delegate createStream in ResizeImage and ScrollAwareImageProvider (flutter/flutter#194756) 2026-11-05 [email protected] [iOS] Introduce FlutterShell and move thread host and profiler (flutter/flutter#195388) 2026-11-05 [email protected] [web] Support FragmentShader.getImageSampler on CanvasKit and Skwasm (flutter/flutter#195854) 2026-11-05 [email protected] Deprecates setFloat API (flutter/flutter#195505) 2026-11-05 [email protected] [flutter_tools] Remove public GlobalToolContext and globals from runner (flutter/flutter#195561) 2026-11-05 [email protected] Defer TLHC PlatformViewWrapper frame post and avoid initial 1x1 buffer resize (flutter/flutter#195861) 2026-11-05 [email protected] Roll Skia from b5abed66da86 to a5aacd103e68 (17 revisions) (flutter/flutter#196054) 2026-11-05 [email protected] Made `FlutterWindowControllerSizeTest.SizedToContentNotResizable` more robust (flutter/flutter#195845) 2026-11-05 [email protected] Update docs for contributor ladder (flutter/flutter#196011) 2026-11-05 [email protected] [Impeller] Use the transfer stage for the Vulkan readback barrier (flutter/flutter#194991) 2026-11-05 [email protected] Remove Mac mac_unopt builder (flutter/flutter#196027) 2026-11-05 [email protected] Updated Instructions for Determining Gradle Version for `gradle_dists` in CIPD (flutter/flutter#193310) 2026-11-05 [email protected] Move ios_app_with_extensions_test into the tool integration shard (flutter/flutter#195609) 2026-11-05 [email protected] [web] Respect Uint8List view bounds when detecting animated WebP/GIF (flutter/flutter#196010) 2026-11-05 [email protected] Add platform_views_layout to build_tests so iOS/Android build breaks are caught in presubmit (flutter/flutter#192985) 2026-11-05 [email protected] [flutter_tools] Detect macOS TCC permission crashes and provide diagnostic guidance (flutter/flutter#192432) 2026-11-05 [email protected] Roll Packages from 670b30e to 0478162 (15 revisions) (flutter/flutter#196047) 2026-11-05 [email protected] [web] Support Skwasm rendering without bitmap capture (flutter/flutter#195103) 2026-11-05 [email protected] [flutter_tools] Reland fix for local CanvasKit asset paths on Windows (flutter/flutter#195770) 2026-11-05 [email protected] Roll Skia from f96be51af95d to b5abed66da86 (14 revisions) (flutter/flutter#196017) 2026-11-05 [email protected] Split chrome web engine test drone (flutter/flutter#195873) 2026-11-05 [email protected] Roll Dart SDK from c9153304136a to 6623b84628f3 (1 revision) (flutter/flutter#196026) 2026-11-05 [email protected] Roll ICU from 4fe960221710 to a0ea93436c52 (6 revisions) (flutter/flutter#196025) 2026-11-05 [email protected] Add more guidance in README and AGENTS for contributing to flutter_tools (flutter/flutter#195998) 2026-11-05 [email protected] Roll Fuchsia Linux SDK from p0HDXLISPIElJfSz7... to Fqe3UlLwAohsPbsCS... (flutter/flutter#196019) 2026-11-05 [email protected] Roll Dart SDK from e362a23e9738 to c9153304136a (18 revisions) (flutter/flutter#196014) 2026-11-05 [email protected] [Impeller] Fix dilation input bounds when clipping saveLayers (flutter/flutter#195652) 2026-11-05 [email protected] Add `variantOf` to the M3E migration checklist (flutter/flutter#195099) 2026-11-05 [email protected] [flutter_tools] Eliminate globals from remaining subsystem files (flutter/flutter#195555) 2026-11-05 [email protected] Fix gap flipping when dragging variable height reorderable items (flutter/flutter#194478) 2026-11-05 [email protected] [A11y] Send un-merged SemanticsNodes in the same update that first references them (flutter/flutter#195829) ...
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
AnimatedCrossFadepassesdurationandreverseDurationtoAnimatedSize. ButAnimatedSizeis an implicit animation. ItsRenderAnimatedSizecontroller only runs forward, so it never usesreverseDuration. Thus, whencrossFadeStatechanges fromshowSecondtoshowFirst, the fade usesreverseDuration, but the size animation usesduration.This change makes
AnimatedCrossFadeselect the size duration from the status of its own controller:AnimationStatus.reverse:reverseDuration, ordurationifreverseDurationis null.duration.AnimatedCrossFadeno longer passesreverseDurationtoAnimatedSize, because it had no effect. The public APIs ofAnimatedSizeandRenderAnimatedSizedo not change.When the widget is idle on either child, a size change of that child continues to use
duration, as before.A possible follow-up (not in this PR): deprecate
AnimatedSize.reverseDurationandRenderAnimatedSize.reverseDuration, because neither has an effect.Fixes #127780
Tests
Two new tests in
packages/flutter/test/widgets/animated_cross_fade_test.dart:AnimatedCrossFade size animation uses reverseDuration when showing first child: fails before this change (Expected Size(150.0, 150.0), Actual Size(100.0, 100.0)), passes after it.AnimatedCrossFade resizes the first child with duration after a reverse transition: after ashowSecondtoshowFirsttransition settles, the first child changes its own size, and the size animation usesduration.After this change:
test/widgets/animated_cross_fade_test.dart: +19, all tests passed.StepperandExpansionPanelListuseAnimatedCrossFade.test/material/stepper_test.dartandtest/material/expansion_panel_test.dart: +86, all tests passed.Pre-launch Checklist
///). No doc change is necessary.If you need help, consider asking for advice on the #hackers-new channel on Discord.