react / react/react-native

maintainVisibleContentPosition incorrectly autoscrolls on ios

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#42,915 7 commenti 2 reazioni 0 assegnatari Vedi su GitHub

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Issue: Author Provided Repro Needs: Triage :mag: Platform: iOS
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Descrizione

Description

What I want is for flatlist to maintain its position if the offset is larger than 10, otherwise automatically scroll to new content, so I am using the maintainVisibleContentPosition with values of { minIndexForVisible: 0, autoscrollToTopThreshold: 10, }. Now this works correctly on android but not on ios.

Here is a small reproducible or its snack:

import React, {useState} from 'react';
import {
  SafeAreaView,
  View,
  FlatList,
  StyleSheet,
  Text,
  StatusBar,
  Button,
} from 'react-native';

type ItemProps = {title: string};

const Item = ({title}: ItemProps) => (
  <View style={styles.item}>
    <Text style={styles.title}>{title}</Text>
  </View>
);

const App = () => {
  const [data, setData] = useState([1, 2, 3, 4, 5, 6, 7, 8, 9]);

  const addToTop = () => {
    setData([data[0] - 1, ...data]);
  };

  const removeFromTop = () => {
    const [_, ...rest] = data;
    setData(rest);
  };

  return (
    <SafeAreaView style={styles.container}>
      <FlatList
        maintainVisibleContentPosition={{ minIndexForVisible: 0, autoscrollToTopThreshold: 10, }}
        data={data}
        renderItem={({item}) => <Item title={`Item ${item}`} />}
        keyExtractor={item => item.toString()}
      />
      <Button title="add to top" onPress={addToTop} />
      <Button title="remove from top" onPress={removeFromTop} />
    </SafeAreaView>
  );
};

const styles = StyleSheet.create({
  container: {
    flex: 1,
    marginTop: StatusBar.currentHeight || 0,
  },
  item: {
    backgroundColor: '#f9c2ff',
    padding: 20,
    marginVertical: 8,
    marginHorizontal: 16,
    height: 480,
  },
  title: {
    fontSize: 32,
  },
});

export default App;
Steps to reproduce
  1. Copy the repro above to some rn project
  2. Scroll to half of the first element, then press addToTop, on android position will be maintained which is correct but on ios it autoscrolls.
React Native Version

0.73.4

Affected Platforms

Runtime - iOS

Output of npx react-native info
System:
  OS: macOS 14.1.2
  CPU: (16) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
  Memory: 2.57 GB / 16.00 GB
  Shell:
    version: "5.9"
    path: /bin/zsh
Binaries:
  Node:
    version: 18.17.1
    path: ~/.nvm/versions/node/v18.17.1/bin/node
  Yarn:
    version: 1.22.19
    path: ~/.nvm/versions/node/v18.17.1/bin/yarn
  npm:
    version: 9.6.7
    path: ~/.nvm/versions/node/v18.17.1/bin/npm
  Watchman:
    version: 2024.01.22.00
    path: /usr/local/bin/watchman
Managers:
  CocoaPods:
    version: 1.15.0
    path: /Users/ramiel/.rbenv/shims/pod
SDKs:
  iOS SDK:
    Platforms:
      - DriverKit 23.2
      - iOS 17.2
      - macOS 14.2
      - tvOS 17.2
      - visionOS 1.0
      - watchOS 10.2
  Android SDK: Not Found
IDEs:
  Android Studio: 2023.1 AI-231.9392.1.2311.11076708
  Xcode:
    version: 15.2/15C500b
    path: /usr/bin/xcodebuild
Languages:
  Java:
    version: 11.0.15
    path: /usr/local/opt/openjdk@11/bin/javac
  Ruby:
    version: 2.7.6
    path: /Users/ramiel/.rbenv/shims/ruby
npmPackages:
  "@react-native-community/cli": Not Found
  react:
    installed: 18.2.0
    wanted: 18.2.0
  react-native:
    installed: 0.73.4
    wanted: 0.73.4
  react-native-macos: Not Found
npmGlobalPackages:
  "*react-native*": Not Found
Android:
  hermesEnabled: true
  newArchEnabled: false
iOS:
  hermesEnabled: true
  newArchEnabled: false


### Stacktrace or Logs

```text
No Stacktrace or Logs
Reproducer

https://snack.expo.dev/@ramiel99/spunky-green-peanut

Screenshots and Videos

https://github.com/facebook/react-native/assets/80689446/456e98f1-d5a8-4253-9a53-9b8d08e61426

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  4. Apri una pull request che faccia riferimento al numero della issue.

Direzione di ricerca

Inizia eseguendo lo Snack collegato su iOS e Android e prova maintainVisibleContentPosition di FlatList con le azioni add-to-top e remove-from-top. Traccia il comportamento di FlatList intorno alla soglia segnalata, quindi verifica che iOS mantenga l'offset quando è superiore a 10 e esegua l'autoscroll solo quando si trova entro la soglia, come Android.

Scritto dal modello di indicizzazione a partire dal testo della issue.

Valutazione

Stack tecnologico
ios, react-native
Ambito
mobile
Tipo di issue
Bug
Difficoltà
4/5
Tempo stimato
3-5 giorni
Stato di attività
Ferma
Chiarezza
Abbastanza chiara
Idoneità per principianti
42/100

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