01c0c4ed3b
Summary: Pull Request resolved: https://github.com/facebook/yoga/pull/1256 X-link: https://github.com/facebook/react-native/pull/37076 This adds a `YGErrata` bitset enum matching the API and guarantees described in https://github.com/facebook/yoga/issues/1247. It is hooked up in later diffs. There are a couple of `YGExperimentalFeature` values that belong here, but keeping the current options means that the default `YGErrataNone` corresponds to existing default behavior, letting us stage the series of changes as: 1. Implement errata API 2. Update internal Yoga users we want to de-risk to `YGErrataClassic` or `YGErrataAll` (if setting `UseLegacyStretchBehaviour`) 3. Add new errata, changing Yoga defaults to be conformant, while letting internal apps opt into compatibility modes pending experimentation. I also added a macro to let C++ users of Yoga perform bitwise operations on the enum without casting (already available for C users). Reviewed By: rshest Differential Revision: D45254098 fbshipit-source-id: d4b61271a8018f548f2d9d8c953db4b121a502d1
yoga-layout
This package provides prebuilt JavaScript bindings for the Yoga layout engine. Both WebAssembly and asm.js variants are packaged, with the optimal loaded based on platform.
Usage
The default entrypoint provides an asynchronous loader function to return a Yoga instance.
import { loadYoga, ALIGN_CENTER } from "yoga-layout";
const Yoga = await loadYoga();
const node = Yoga.Node.create();
node.setAlignContent(ALIGN_CENTER);
An alternative synchronous API is provided for compatibility, but requires using asm.js in browsers instead of WebAssembly, leading to worse performance and larger assets.
import Yoga, { ALIGN_CENTER } from "yoga-layout/sync";
const node = Yoga.Node.create();
node.setAlignContent(ALIGN_CENTER);
Objects created by Yoga.<>.create() are not automatically garbage collected and should be freed once they are no longer in use.
// Free a config
config.free();
// Free a tree of Nodes
node.freeRecursive();
// Free a single Node
node.free();
Selecting WebAssembly or asm.js
For better performance and smaller packages, WebAssembly is preferred to asm.js where available. yoga-layout tries to provide the right default using export maps so that platforms which can take advantage of WebAssembly use it by default.
A specific entrypoint may be specified on platforms which do not understand export conditions.
import { loadYoga } from "yoga-layout/dist/entrypoint/wasm-async";
Contributing
Requirements
- Emscripten SDK
- CMake >= 3.13
- (Optional) ninja, for faster builds
Building
git clone https://github.com/facebook/yoga.git
cd yoga/javascript
yarn install
yarn build
Testing
# Build and test all entrypoints
yarn test
# Build and test a specific entrypoint
yarn test:asmjs-sync