Text renders 1px bigger than View when explicitly given the same height with a specific combination of height and pixel ratio.
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Description
Description
Explicitly setting height: 15 on a parent View and child Text on a device with a pixel ratio of 3.5 (Pixel 7 Pro emulator) causes the child Text to render 1 px bigger than the parent View due to rounding in Yoga. When the Text is given a small border (borderWidth: 0.5) the bottom of the border is clipped by the parent View. This only happens with a certain offset from top - achieved for example by setting marginTop: 295.
There are several values and combinations of height and pixelRatio that give this result. I've only observed this on Fabric, on old architecture it renders the same.
Steps to reproduce
- Enable new architecture
- Use the following code:
const print_height = (layout: LayoutRectangle, component: string) => {
const {height} = layout;
console.log(`${component}'s height = ${height}`);
};
const TestApp = () => {
return (
<View
style={styles.View}
onLayout={event => print_height(event.nativeEvent.layout, 'View')}>
<Text
style={styles.Text}
onLayout={event => print_height(event.nativeEvent.layout, 'Text')}>
kkkkkkkk
</Text>
</View>
);
};
const styles = StyleSheet.create({
View: {
justifyContent: 'center',
alignItems: 'center',
overflow: 'hidden',
height: 15,
marginTop: 295,
},
Text: {
fontSize: 8,
overflow: 'hidden',
height: 15,
borderWidth: 0.5,
borderRadius: 4,
},
});
- Run on a device/emulator with
pixelRatio: 3.5(ex. Pixel 7 Pro)
React Native Version
0.73.1
Affected Platforms
Runtime - Android
Areas
Fabric - The New Renderer
Output of npx react-native info
System:
OS: macOS 13.5.2
CPU: (8) arm64 Apple M1 Pro
Memory: 100.84 MB / 16.00 GB
Shell:
version: "5.9"
path: /bin/zsh
Binaries:
Node:
version: 20.8.0
path: /opt/homebrew/bin/node
Yarn:
version: 1.22.21
path: /opt/homebrew/bin/yarn
npm:
version: 10.1.0
path: /opt/homebrew/bin/npm
Watchman:
version: 2023.09.25.00
path: /opt/homebrew/bin/watchman
Managers:
CocoaPods: Not Found
SDKs:
iOS SDK:
Platforms:
- DriverKit 23.2
- iOS 17.2
- macOS 14.2
- tvOS 17.2
- watchOS 10.2
Android SDK: Not Found
IDEs:
Android Studio: 2022.3 AI-223.8836.35.2231.10406996
Xcode:
version: 15.1/15C65
path: /usr/bin/xcodebuild
Languages:
Java:
version: 17.0.6
path: /usr/bin/javac
Ruby:
version: 3.2.2
path: /opt/homebrew/opt/ruby/bin/ruby
npmPackages:
"@react-native-community/cli": Not Found
react:
installed: 18.2.0
wanted: 18.2.0
react-native:
installed: 0.73.1
wanted: 0.73.1
react-native-macos: Not Found
npmGlobalPackages:
"*react-native*": Not Found
Android:
hermesEnabled: true
newArchEnabled: true
iOS:
hermesEnabled: Not found
newArchEnabled: false
Stacktrace or Logs
n\a
Reproducer
https://github.com/zglapa/reproducer_view_text_size
Screenshots and Videos
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
The issue names no repository files or tests. Start by running the linked reproducer with Fabric enabled on an Android device or emulator using a 3.5 pixel ratio, then trace the layout rounding behavior in the Fabric/Yoga path. Done means the explicitly equal View and Text heights remain equal and the half-pixel border is not clipped for the reported reproduction.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- android, react
- Domain
- mobile-dev
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 38/100