37a94a86de
Summary: Pull Request resolved: https://github.com/facebook/yoga/pull/1809 X-link: https://github.com/facebook/react-native/pull/51181 We want to know if an artifact created during measurement can fully be reused after final layout, but the final layout is allowed to be slightly larger due to pixel grid rounding (while still allowing reuse). It's hard to tell after the fact, whether it is larger because of this rounding (though the measure is used), or if it may be a pixel larger for valid reasons. We can expose the unsnapped dimensions of a node to give us this information, and to correlate measurement artifacts. This is most of the time the same as the layout's measured dimension, though I don't think it's safe to use this, since anything else measuring the node after could clobber this (I think `YGNodeLayoutGetOverflow` may also be prone to this as a bug). Changelog: [Internal] Reviewed By: rshest Differential Revision: D74292949 fbshipit-source-id: 05011c66a9a9480544313eb1dfe2c46bf7742bac
Yoga 
Yoga is an embeddable and performant flexbox layout engine with bindings for multiple languages.
Building
Yoga's main implementation targets C++ 20 with accompanying build logic in CMake. A wrapper is provided to build the main library and run unit tests.
./unit_tests <Debug|Release>
While not required, this script will use ninja if it is installed for faster builds.
Yoga is additionally part of the vcpkg collection of ports maintained by Microsoft and community contributors. If the version is out of date, please create an issue or pull request on the vcpkg repository.
Adding Tests
Many of Yoga's tests are automatically generated, using HTML fixtures describing node structure. These are rendered in Chrome to generate an expected layout result for the tree. New fixtures can be added to gentest/fixtures.
<div id="my_test" style="width: 100px; height: 100px; align-items: center;">
<div style="width: 50px; height: 50px;"></div>
</div>
To generate new tests from added fixtures:
- Ensure you have yarn classic installed.
- Run
yarn installto install dependencies for the test generator. - Run
yarn gentestin theyogadirectory.
Debugging
Yoga provides a VSCode "launch.json" configuration which allows debugging unit tests. Simply add your breakpoints, and run "Debug C++ Unit tests (lldb)" (or "Debug C++ Unit tests (vsdbg)" on Windows).