86a202b1b6
Summary: This changes public Yoga API to in more places accept const structures where before they required mutable ones. This tries to avoid more breaking changes yet, e.g. changing callbacks to require clients do not modify nodes when they are passed for logging. We also don't have const variants for returning child structures which would allow mutation of dependencies of the const object. These would need new names under the public API, since we do not have operator overloading in C. Differential Revision: D49130412 fbshipit-source-id: b14f2b09652e53c04056249a220ee607d0f1bf20
Yoga 
Yoga is an embeddable and performant flexbox layout engine with bindings for multiple languages.
Building
Yoga's main implementation targets C++ 17 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 If the version is out of date, please create an issue or pull request on the vcpkg repository.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:
- Run
bundle installin thegentestdirectory to install dependencies of the test generator. - Run
ruby gentest.rbin thegentestdirectory.
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).