Adam ComellaandLorenzo Sciandra
1131463069
Summary:
If a view inside of an inline view became dirty (e.g. its top/left prop changed), its position would not update on screen. This is because Yoga didn't know the view needed to be relaid out because Yoga's dirty signal didn't propagate all the way up to the root.
The problem is that inline views don't have a parent in the Yoga tree causing Yoga's dirtiness signal propagation to get cut off early. The fix is, when an inline views gets dirty, mark the parent Text's Yoga node as dirty. This will cause Yoga's dirtiness signal to propagate all the way up to the root node.
Yoga has a hook to inform you when your node is marked as dirty: `YGNodeSetDirtiedFunc`. We leverage this to find out when an inline view's Yoga node gets dirtied.
React Native almost handled this case. Everything worked fine as long as the inline view was nested inside of a virtual text node like this:
```
<Text>
<Text>
<InlineView />
</Text>
</Text>
```
However, the bug repros when the inline view is nested in a non-virtual text node:
```
<Text>
<InlineView />
</Text>
```
The fix is to move the special dirtiness propagation logic from `RCTVirtualTextShadowView` to `RCTBaseTextShadowView`.
**Test Plan**
Created an inline view. Tested the following kinds of updates on the inline view's content:
- Moved the content
- Removed the content
- Added the content
Tested this for an inline view that is directly inside of a text node as well as one that is nested under a virtual text node.
Here's the code I used for the inline view that moved its content after 2 seconds:
```
const RN = require('react-native');
const React = require('react');
export default class InlineView extends React.Component {
constructor(props, context) {
super(props, context);
this.state = { posBottom: false };
}
componentDidMount() {
super.componentDidMount && super.componentDidMount();
setTimeout(() => { this.setState({ posBottom: true }); }, 2000);
}
render() {
const pos = this.state.posBottom ? 25 : 0;
const color = this.state.posBottom ? 'pink' : 'green';
return (
<RN.View style={{ width: 50, height: 50, backgroundColor: 'steelblue'}}>
<RN.View style={{ width: 25, height: 25, top: pos, left: pos, backgroundColor: color }} />
</RN.View>
);
}
}
```
**Release Notes**
[IOS] [BUGFIX] [Text] - Fix case where content of inline views didn't get relaid out
Adam Comella
Microsoft Corp.
Pull Request resolved: https://github.com/facebook/react-native/pull/21968
Differential Revision: D12873795
Pulled By: shergin
fbshipit-source-id: bbc9f5d3ef25063b0015cec8c4aaf2e41ecd60a8
React Native · 
Learn once, write anywhere: Build mobile apps with React.
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- Don't waste time recompiling: React Native lets you build your app faster. Instead of recompiling, you can reload your app instantly. With hot reloading, you can even run new code while retaining your application state. Give it a try - it's a magical experience.
- Use native code when you need to: React Native combines smoothly with components written in Objective-C, Java, or Swift. It's simple to drop down to native code if you need to optimize a few aspects of your application. It's also easy to build part of your app in React Native, and part of your app using native code directly - that's how the Facebook app works.
The focus of React Native is on developer efficiency across all the platforms you care about - learn once, write anywhere. Facebook uses React Native in multiple production apps and will continue investing in React Native.
See the official React Native website for an introduction to React Native.
Supported operating systems are >= Android 4.1 (API 16) and >= iOS 9.0.
Getting Started
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:
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The website’s documentation is divided into multiple sections.
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- The Components section covers React components such as
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Another great way to learn more about the components and APIs included with React Native is to read their source. Look under the Libraries/Components directory for components like ScrollView and TextInput, for example. The RNTester example is also here to demonstrate some of the ways to use these components. From the source you can get an accurate understanding of each component’s behavior and API.
The React Native documentation only discusses the components, APIs and topics specific to React Native (React on iOS and Android). For further documentation on the React API that is shared between React Native and React DOM, refer to the React documentation.
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