Rubén Norte
b1e8729f4d
Summary: Pull Request resolved: https://github.com/facebook/react-native/pull/51379 Changelog: [General][Fixed] Fix incorrect flattening / non-rendering of views with backgroundColor set to `rgba(255, 255, 255, 127/256)` Fixes #51378. ## Context When testing some unrelated things with Fantom is realized that the color for some text that I wasn't explicitly defining was being set to `rgba(255, 255, 255, 127)`, like here: https://github.com/facebook/react-native/blob/249a24ac756275eadbe3b4df1ff9c974af1671d2/packages/react-native-fantom/src/__tests__/Fantom-itest.js#L540-L542 When digging a bit more about why, I realized that was actually the value for `UndefinedColor`. When looking a bit deeper, I saw that the value for that constant was being set like this: ``` using Color = int32_t; namespace HostPlatformColor { static const facebook::react::Color UndefinedColor = std::numeric_limits<facebook::react::Color>::max(); } ``` I'm not sure what the logic could've been here: - Defining it as a value out of bounds for all valid colors? In this case, it's a 32 bit value so all the range of values are actually valid RGBA colors. - Defining it as a fully opaque white? Seems dangerous for a default because you wouldn't be able to distinguish a explicitly set white color from a non-set color, relevant if you're seeing a white background color in a view on top of another view with any other background color. The result of this existing logic was actually setting `UndefinedColor` to `rgba(255, 255, 255, 127)` because the alpha channel is defined in the first bits of the value, and `Color` being a signed int with 32 bits, the largest value is `01111....1`, so extracting the first 8 bits, you get 127. ## Changes This changes the value set for the `UndefinedColor` constant (which is used, among other things, to determine if a view sets a background color, or otherwise could potentially be flattened). The new value, instead of white with a 127/256 opacity, is black with 0% opacity (or simply the number 0 in `int32_t`). Reviewed By: javache Differential Revision: D74869311 fbshipit-source-id: 5582b4803b0b5c72cb3c1b33720c4542c5e3f1de
React Native
Learn once, write anywhere:
Build mobile apps with React.
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React Native brings React's declarative UI framework to iOS and Android. With React Native, you use native UI controls and have full access to the native platform.
- Declarative. React makes it painless to create interactive UIs. Declarative views make your code more predictable and easier to debug.
- Component-Based. Build encapsulated components that manage their state, then compose them to make complex UIs.
- Developer Velocity. See local changes in seconds. Changes to JavaScript code can be live reloaded without rebuilding the native app.
- Portability. Reuse code across iOS, Android, and other platforms.
React Native is developed and supported by many companies and individual core contributors. Find out more in our ecosystem overview.
Contents
- Requirements
- Building your first React Native app
- Documentation
- Upgrading
- How to Contribute
- Code of Conduct
- License
📋 Requirements
React Native apps may target iOS 15.1 and Android 7.0 (API 24) or newer. You may use Windows, macOS, or Linux as your development operating system, though building and running iOS apps is limited to macOS. Tools like Expo can be used to work around this.
🎉 Building your first React Native app
Follow the Getting Started guide. The recommended way to install React Native depends on your project. Here you can find short guides for the most common scenarios:
📖 Documentation
The full documentation for React Native can be found on our website.
The React Native documentation discusses components, APIs, and topics that are specific to React Native. For further documentation on the React API that is shared between React Native and React DOM, refer to the React documentation.
The source for the React Native documentation and website is hosted on a separate repository, @facebook/react-native-website.
🚀 Upgrading
Upgrading to new versions of React Native may give you access to more APIs, views, developer tools, and other goodies. See the Upgrading Guide for instructions.
React Native releases are discussed in this discussion repo.
👏 How to Contribute
The main purpose of this repository is to continue evolving React Native core. We want to make contributing to this project as easy and transparent as possible, and we are grateful to the community for contributing bug fixes and improvements. Read below to learn how you can take part in improving React Native.
Code of Conduct
Facebook has adopted a Code of Conduct that we expect project participants to adhere to. Please read the full text so that you can understand what actions will and will not be tolerated.
Contributing Guide
Read our Contributing Guide to learn about our development process, how to propose bugfixes and improvements, and how to build and test your changes to React Native.
Open Source Roadmap
You can learn more about our vision for React Native in the Roadmap.
Good First Issues
We have a list of good first issues that contain bugs which have a relatively limited scope. This is a great place to get started, gain experience, and get familiar with our contribution process.
Discussions
Larger discussions and proposals are discussed in @react-native-community/discussions-and-proposals.
📄 License
React Native is MIT licensed, as found in the LICENSE file.