Reimplemented StretchingOverscrollIndicator with Simulation ported from Android 12. #173849
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This pull request is a great improvement to the StretchingOverscrollIndicator, replacing the previous animation logic with a more physically realistic SpringSimulation. This results in a much more natural feel, especially for high-velocity flings, aligning it better with native Android behavior. The code is well-structured, and the addition of a regression test is appreciated.
I've found a critical issue related to animation controller lifecycle management that could lead to race conditions. I've also identified a couple of medium-severity issues related to code clarity and maintainability. Addressing these will make the implementation more robust and easier to understand.
Overall, this is a high-quality contribution.
dkwingsmt
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Thank you for this amazing change! My first round of review focuses on the constants for the spring simulation. |
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Looked through the screenshot tests, they all look intended with this PR. |
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Roll Flutter from 5b8720312a94 to b2de367c41e0 (38 revisions) flutter/flutter@5b87203...b2de367 2025-12-08 [email protected] Roll Packages from b17d3ff to 33a9a81 (3 revisions) (flutter/flutter#179579) 2025-12-08 [email protected] Roll Fuchsia Linux SDK from XCoAHsnYnKrvuWU2o... to _pSztGZvEA3-Ry-GW... (flutter/flutter#179575) 2025-12-08 [email protected] Implementation of `TestWindowingOwner` for testing multi-window (flutter/flutter#179355) 2025-12-08 [email protected] Roll Dart SDK from 11efe37089a7 to 75899721aa42 (2 revisions) (flutter/flutter#179573) 2025-12-08 [email protected] Roll Skia from 0c016e4aefd5 to b1936c760645 (8 revisions) (flutter/flutter#179568) 2025-12-08 [email protected] Roll Skia from 3c5f9e0c9269 to 0c016e4aefd5 (1 revision) (flutter/flutter#179565) 2025-12-08 [email protected] Roll Dart SDK from 1a6c6f6398af to 11efe37089a7 (1 revision) (flutter/flutter#179564) 2025-12-07 [email protected] Roll Skia from 4830855b6f84 to 3c5f9e0c9269 (1 revision) (flutter/flutter#179561) 2025-12-07 [email protected] Roll Skia from d5a6b6af6d12 to 4830855b6f84 (1 revision) (flutter/flutter#179557) 2025-12-07 [email protected] Roll Fuchsia Linux SDK from KilaJW3p3J_0yUDtV... to XCoAHsnYnKrvuWU2o... (flutter/flutter#179551) 2025-12-06 [email protected] Roll Skia from 33b32cecb287 to d5a6b6af6d12 (1 revision) (flutter/flutter#179540) 2025-12-06 [email protected] Roll Dart SDK from ea201dd2ef12 to 1a6c6f6398af (1 revision) (flutter/flutter#179539) 2025-12-06 [email protected] Roll Dart SDK from d1d30ee8d5a0 to ea201dd2ef12 (1 revision) (flutter/flutter#179537) 2025-12-06 [email protected] Roll Dart SDK from 30c906aa00f2 to d1d30ee8d5a0 (1 revision) (flutter/flutter#179534) 2025-12-06 [email protected] Roll Skia from dccd48c6c6ab to 33b32cecb287 (2 revisions) (flutter/flutter#179531) 2025-12-06 [email protected] Roll Fuchsia Linux SDK from vDeTl_KBeLJY8nCAx... to KilaJW3p3J_0yUDtV... (flutter/flutter#179530) 2025-12-06 [email protected] Roll Dart SDK from f3690c23d422 to 30c906aa00f2 (2 revisions) (flutter/flutter#179529) 2025-12-06 [email protected] Roll Skia from e19670f70406 to dccd48c6c6ab (6 revisions) (flutter/flutter#179524) 2025-12-05 [email protected] Make sure that a CupertinoFormRow doesn't crash in 0x0 environment (flutter/flutter#178979) 2025-12-05 [email protected] Make sure that a CupertinoContextMenuAction doesn't crash in 0x0 envi… (flutter/flutter#178721) 2025-12-05 [email protected] Make sure that a CupertinoRadio doesn't crash in 0x0 environment (flutter/flutter#179378) 2025-12-05 [email protected] Make sure that a CupertinoSearchTextField doesn't crash in 0x0 enviro… (flutter/flutter#179487) 2025-12-05 [email protected] Make sure that a CupertinoPicker doesn't crash in 0x0 environment (flutter/flutter#179258) 2025-12-05 [email protected] Make sure that a CupertinoAlertDialog doesn't crash in 0x0 environment (flutter/flutter#178858) 2025-12-05 [email protected] Make sure that a CupertinoListTileChevron doesn't crash in 0x0 enviro… (flutter/flutter#179165) 2025-12-05 [email protected] Make sure that CupertinoNavigationBar doesn't crash in 0x0 environment (flutter/flutter#179235) 2025-12-05 [email protected] Replace dropdown button with dropdown menu (flutter/flutter#179095) 2025-12-05 [email protected] Make sure that a CupertinoCheckbox doesn't crash in 0x0 environment (flutter/flutter#178630) 2025-12-05 [email protected] Make sure that a CupertinoApp doesn't crash in 0x0 environment (flutter/flutter#178610) 2025-12-05 [email protected] Make sure that a CupertinoButton doesn't crash in 0x0 environment (flutter/flutter#178629) 2025-12-05 [email protected] Make sure that a CupertinoTimerPicker doesn't crash in 0x0 environment (flutter/flutter#178857) 2025-12-05 [email protected] Make sure that a CupertinoScrollbar doesn't crash in 0x0 environment (flutter/flutter#179442) 2025-12-05 [email protected] Roll Dart SDK from 0fcab487446d to f3690c23d422 (1 revision) (flutter/flutter#179517) 2025-12-05 [email protected] Update several comments related to theme normalization (flutter/flutter#179457) 2025-12-05 [email protected] Reimplemented StretchingOverscrollIndicator with Simulation ported from Android 12. (flutter/flutter#173849) 2025-12-05 [email protected] Roll Skia from a31411879251 to e19670f70406 (1 revision) (flutter/flutter#179511) 2025-12-05 [email protected] chore: mark tests as flaky (flutter/flutter#179518) 2025-12-05 [email protected] Roll Dart SDK from 42fe3327abca to 0fcab487446d (3 revisions) (flutter/flutter#179506) 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 ...
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…om Android 12. (flutter#173849) Fixed an issue flutter#169659 This PR improves the StretchingOverscrollIndicator to better match native Android behavior. - Previously, the stretch effect worked well only for slow dragging, and during fast flings it was absent or felt clipped. - Implemented a Simulation-based animation that responds naturally to both slow drags and high-velocity flings. - The result closely resembles the native Android overscroll behavior while maintaining Flutter's performance characteristics. This change ensures that momentum-based gestures produce a more natural and intuitive overscroll experience, especially for users accustomed to native Android scroll views. ## Fling [fling](https://github.com/user-attachments/assets/3944eef3-baaa-47df-82ca-9c49d4283fe4) ## Pull And Reduce Also, a very similar animation is implemented when pulling as well. [pull](https://github.com/user-attachments/assets/2a3025dc-0996-403d-b58b-d07f25487cda) ## Pre-launch Checklist - [x] I read the [Contributor Guide] and followed the process outlined there for submitting PRs. - [x] I read the [Tree Hygiene] wiki page, which explains my responsibilities. - [x] I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement]. - [x] I signed the [CLA]. - [x] I listed at least one issue that this PR fixes in the description above. - [x] I updated/added relevant documentation (doc comments with `///`). - [x] I added new tests to check the change I am making, or this PR is [test-exempt]. - [x] I followed the [breaking change policy] and added [Data Driven Fixes] where supported. - [x] All existing and new tests are passing. --------- Co-authored-by: Tong Mu <[email protected]> Co-authored-by: Victor Sanni <[email protected]>
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Fixed an issue #169659
This PR improves the StretchingOverscrollIndicator to better match native Android behavior.
This change ensures that momentum-based gestures produce a more natural and intuitive overscroll experience, especially for users accustomed to native Android scroll views.
Fling
3.mp4
Pull And Reduce
Also, a very similar animation is implemented when pulling as well.
3.mp4
Pre-launch Checklist
///).