Skip to content

Conversation

@NickGerleman
Copy link
Contributor

Summary:
Fixes #41545

SafeAreaView works by adding padding in order to shift content out of the safe area. This may change the layout dimensions of the SafeAreaView, in turn effecting its safe area insets.

This can cause layout results to change, which in turn changes the inset value. Because of this, there is a tolerance, where safe area inset changes do not trigger a new update.

Yoga is instructed to round layout dimensions to the closest physical pixel, so a very small difference in layout may result being off by about a pixel. Right now the tolerance is exactly one physical pixel, and if there is FP error here, we may not pass the test, and start oscillating with different layout values.

After changing affected ShadowNode order to always be root-first, the first call to set the frame of the SafeAreaView happens when a non-zero-sized RootView is present, which I think may lead to a safe area inset update communicated that wasn't before? Or other cosmic butterflies. Layout rounds to one physical pixel in difference, and our tolerance is 0.00001 dips off (not helped that 1/3 screen scale cannot be represented as decimal, even without FP error).

This adds a small tolerance beyond just the pixel boundary, matching the logic in Fabric, which seems to resolve the issue.

Changelog:
[iOS][Fixed] - FP Tolerance in iOS Paper SafeAreaView debouncing

Reviewed By: philIip

Differential Revision: D51539091

@facebook-github-bot facebook-github-bot added CLA Signed This label is managed by the Facebook bot. Authors need to sign the CLA before a PR can be reviewed. p: Facebook Partner: Facebook Partner labels Nov 22, 2023
@facebook-github-bot
Copy link
Contributor

This pull request was exported from Phabricator. Differential Revision: D51539091

Summary:

Fixes facebook#41545

SafeAreaView works by adding padding in order to shift content out of the safe area. This may change the layout dimensions of the SafeAreaView, in turn effecting its safe area insets.

This can cause layout results to change, which in turn changes the inset value. Because of this, there is a tolerance, where safe area inset changes do not trigger a new update.

Yoga is instructed to round layout dimensions to the closest physical pixel, so a very small difference in layout may result being off by about a pixel. Right now the tolerance is exactly one physical pixel, and if there is FP error here, we may not pass the test, and start oscillating with different layout values.

After changing affected ShadowNode order to always be root-first, the first call to set the frame of the `SafeAreaView` happens when a non-zero-sized RootView is present, which I think may lead to a safe area inset update communicated that wasn't before? Or other cosmic butterflies. Layout rounds to one physical pixel in difference, and our tolerance is `0.00001` dips off (not helped that 1/3 screen scale cannot be represented as decimal, even without FP error).

This adds a small tolerance beyond just the pixel boundary, matching the logic in Fabric, which seems to resolve the issue.

Changelog:
[iOS][Fixed] - FP Tolerance in iOS Paper SafeAreaView debouncing

Reviewed By: philIip

Differential Revision: D51539091
@facebook-github-bot
Copy link
Contributor

This pull request was exported from Phabricator. Differential Revision: D51539091

@github-actions
Copy link

This pull request was successfully merged by @NickGerleman in c9c5651.

When will my fix make it into a release? | Upcoming Releases

@github-actions github-actions bot added the Merged This PR has been merged. label Nov 23, 2023
huntie pushed a commit that referenced this pull request Nov 24, 2023
Summary:
Pull Request resolved: #41614

Fixes #41545

SafeAreaView works by adding padding in order to shift content out of the safe area. This may change the layout dimensions of the SafeAreaView, in turn effecting its safe area insets.

This can cause layout results to change, which in turn changes the inset value. Because of this, there is a tolerance, where safe area inset changes do not trigger a new update.

Yoga is instructed to round layout dimensions to the closest physical pixel, so a very small difference in layout may result being off by about a pixel. Right now the tolerance is exactly one physical pixel, and if there is FP error here, we may not pass the test, and start oscillating with different layout values.

After changing affected ShadowNode order to always be root-first, the first call to set the frame of the `SafeAreaView` happens when a non-zero-sized RootView is present, which I think may lead to a safe area inset update communicated that wasn't before? Or other cosmic butterflies. Layout rounds to one physical pixel in difference, and our tolerance is `0.00001` dips off (not helped that 1/3 screen scale cannot be represented as decimal, even without FP error).

This adds a small tolerance beyond just the pixel boundary, matching the logic in Fabric, which seems to resolve the issue.

Changelog:
[iOS][Fixed] - FP Tolerance in iOS Paper SafeAreaView debouncing

Reviewed By: philIip

Differential Revision: D51539091

fbshipit-source-id: 88bddc38c7cd8d93feef5f12da64b124af22f46d
Othinn pushed a commit to Othinn/react-native that referenced this pull request Jan 9, 2024
Summary:
Pull Request resolved: facebook#41614

Fixes facebook#41545

SafeAreaView works by adding padding in order to shift content out of the safe area. This may change the layout dimensions of the SafeAreaView, in turn effecting its safe area insets.

This can cause layout results to change, which in turn changes the inset value. Because of this, there is a tolerance, where safe area inset changes do not trigger a new update.

Yoga is instructed to round layout dimensions to the closest physical pixel, so a very small difference in layout may result being off by about a pixel. Right now the tolerance is exactly one physical pixel, and if there is FP error here, we may not pass the test, and start oscillating with different layout values.

After changing affected ShadowNode order to always be root-first, the first call to set the frame of the `SafeAreaView` happens when a non-zero-sized RootView is present, which I think may lead to a safe area inset update communicated that wasn't before? Or other cosmic butterflies. Layout rounds to one physical pixel in difference, and our tolerance is `0.00001` dips off (not helped that 1/3 screen scale cannot be represented as decimal, even without FP error).

This adds a small tolerance beyond just the pixel boundary, matching the logic in Fabric, which seems to resolve the issue.

Changelog:
[iOS][Fixed] - FP Tolerance in iOS Paper SafeAreaView debouncing

Reviewed By: philIip

Differential Revision: D51539091

fbshipit-source-id: 88bddc38c7cd8d93feef5f12da64b124af22f46d
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

CLA Signed This label is managed by the Facebook bot. Authors need to sign the CLA before a PR can be reviewed. fb-exported Merged This PR has been merged. p: Facebook Partner: Facebook Partner

Projects

None yet

Development

Successfully merging this pull request may close these issues.

0.73.rc iOS oldarch - infinite recursion with -[RCTUIManager setNeedsLayout]

2 participants