Improve documentation of frictionFactor function#184509
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This pull request updates the documentation for BouncingScrollPhysics.frictionFactor to clarify the friction calculation and specify values for different deceleration rates. Feedback was provided to correct the definition of overscrollFraction, noting that it represents the current overscroll amount rather than the cumulative distance dragged.
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| /// The [overscrollFraction] represents the distance the user has dragged past | ||
| /// the edge as a fraction of the [ScrollMetrics.viewportDimension], where 0.0 |
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The documentation states that overscrollFraction represents the "distance the user has dragged past the edge". However, in the implementation of applyPhysicsToUserOffset, this value is calculated as the current distance the scroll position is beyond the scroll extent (the overscroll amount) divided by the viewport dimension. It does not represent the cumulative distance the user has moved their finger during the gesture. Using "amount of overscroll" or "overscroll distance" would be more accurate.
/// The [overscrollFraction] represents the current amount of overscroll as a
/// fraction of the [ScrollMetrics.viewportDimension], where 0.0References
- Documentation should be useful and accurate. Explaining the parameter correctly ensures developers understand how the friction factor is calculated. (link)
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the original change has a better documentation IMO, let's wait for a review.
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frictionFactor function
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This pull request updates the documentation for BouncingScrollPhysics.frictionFactor to clarify overscroll behavior and specify initial friction factors for normal and fast deceleration rates. Feedback suggests refining the definition of overscrollFraction to specify it as a fraction of the viewport dimension and adding a link to ScrollMetrics.viewportDimension to improve clarity and follow documentation guidelines.
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| /// The `overscrollFraction` represents how far past the edge the user has | ||
| /// dragged, where 0.0 means no overscroll. As this value increases, the | ||
| /// friction factor decreases quadratically, making further overscroll harder. |
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The description of overscrollFraction could be more precise. It represents the overscroll distance as a fraction of the viewport dimension, not just "how far" (which might be interpreted as pixels). Additionally, the quadratic decrease only applies as the fraction approaches 1.0 (at which point friction becomes infinite). Providing a link to ScrollMetrics.viewportDimension also helps clarify the term.
/// The `overscrollFraction` represents the overscroll distance as a fraction
/// of the [ScrollMetrics.viewportDimension], where 0.0 means no overscroll.
/// As this value increases towards 1.0, the friction factor decreases
/// quadratically, making further overscroll harder.References
- Documentation should be useful and explain the 'how' and 'why'. Clarifying the scale of parameters and linking to related definitions makes the documentation more useful for developers. (link)
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this is the same comment from before
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Well, I guess it is a good thing Gemini is consistent! 😆
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flutter/flutter@05e0ae0...81c87ea 2026-04-09 [email protected] Remove last material dependency from cupertino tests (flutter/flutter#184781) 2026-04-09 [email protected] Roll Skia from 7c46cb639dba to 4d0f5389e131 (7 revisions) (flutter/flutter#184812) 2026-04-09 [email protected] Make `windowing_test` follow repo analyzer rules (flutter/flutter#184752) 2026-04-09 [email protected] Improve documentation of `frictionFactor` function (flutter/flutter#184509) 2026-04-09 [email protected] Roll Skia from d2b0bd12576a to 7c46cb639dba (1 revision) (flutter/flutter#184796) 2026-04-09 [email protected] Roll Fuchsia GN SDK from JLBh4Z9PKsjIJcqDU... to SEfYx3xgueX3aFAY3... (flutter/flutter#184797) 2026-04-09 [email protected] Fixed freeze flow (flutter/flutter#184793) 2026-04-09 [email protected] Roll pub packages (flutter/flutter#184795) 2026-04-09 [email protected] Roll Skia from e9ed4fc9f154 to d2b0bd12576a (36 revisions) (flutter/flutter#184791) 2026-04-08 [email protected] [Android] Allow sensitive content to gracefully fail when unregistering host before registering (flutter/flutter#184789) 2026-04-08 [email protected] Refactor: remove material from autocomplete_test, scrollable_restoration_test, semantics_tester_generate_test_semantics_expression_for_current_semantics_tree_test (flutter/flutter#184615) 2026-04-08 [email protected] Warn about the use of TestSemantics (flutter/flutter#184369) 2026-04-08 [email protected] Change freeze flow to pull_request_target (flutter/flutter#184785) 2026-04-08 [email protected] Update to the beta dart version for 3.44 branch cut. (flutter/flutter#184770) 2026-04-08 [email protected] [Dot shorthands] Migrate examples/api/test (flutter/flutter#183966) 2026-04-08 [email protected] [fuchsia] Give AOT runners the ability to copy FFI callback thunks. (flutter/flutter#184696) 2026-04-08 [email protected] Add await or ignore lint to invokeMethod callsites (flutter/flutter#182870) 2026-04-08 [email protected] Correctly handle failure to read /proc/self/exe link (flutter/flutter#184700) 2026-04-08 [email protected] Roll Skia from e264d870a380 to e9ed4fc9f154 (11 revisions) (flutter/flutter#184713) 2026-04-08 [email protected] Roll Packages from 5299279 to 0e0a032 (5 revisions) (flutter/flutter#184720) 2026-04-08 [email protected] Roll pub packages (flutter/flutter#184772) 2026-04-08 [email protected] Roll Fuchsia Linux SDK from 1rcChbOv4nSTVkUxs... to pDXMXRIjEHTw7B0sk... (flutter/flutter#184722) 2026-04-08 [email protected] Remove navigator_utils cross-imports from cupertino tests (flutter/flutter#184282) 2026-04-08 [email protected] Even more awaits v2 (flutter/flutter#184552) 2026-04-08 [email protected] Allow personal skills to be gitignored (flutter/flutter#184727) 2026-04-08 [email protected] [ci] mac_arm64 build_test re-enable shard 1 presubmit (flutter/flutter#184751) 2026-04-08 [email protected] Fix repo check on code freeze (flutter/flutter#184771) 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: https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md
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Fixes flutter#95367 ## Pre-launch Checklist - [x] I read the [Contributor Guide] and followed the process outlined there for submitting PRs. - [x] I read the [AI contribution guidelines] and understand my responsibilities, or I am not using AI tools. - [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 `///`). - [ ] 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. If you need help, consider asking for advice on the #hackers-new channel on [Discord]. **Note**: The Flutter team is currently trialing the use of [Gemini Code Assist for GitHub](https://developers.google.com/gemini-code-assist/docs/review-github-code). Comments from the `gemini-code-assist` bot should not be taken as authoritative feedback from the Flutter team. If you find its comments useful you can update your code accordingly, but if you are unsure or disagree with the feedback, please feel free to wait for a Flutter team member's review for guidance on which automated comments should be addressed. <!-- Links --> [Contributor Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview [AI contribution guidelines]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#ai-contribution-guidelines [Tree Hygiene]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md [test-exempt]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests [Flutter Style Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md [Features we expect every widget to implement]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement [CLA]: https://cla.developers.google.com/ [flutter/tests]: https://github.com/flutter/tests [breaking change policy]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes [Discord]: https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md [Data Driven Fixes]: https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md
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Fixes #95367
Pre-launch Checklist
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Note: The Flutter team is currently trialing the use of Gemini Code Assist for GitHub. Comments from the
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