Pause video in flatlist when out of view

here is how i simply did the trick inside my card component that have video

<Video ...
    paused={currentIndex !== currentVisibleIndex}
/>

both currentIndex and currentVisibleIndex are passed the component from the FlatList parent

my FlatList pass the renderItem index as currentIndex

<FlatList
    data={[...]}
    renderItem={({ item, index }) => (
    <GalleryCard
        {...item}
        currentIndex={index}
        currentVisibleIndex={currentVisibleIndex}
        />
        )}
    onViewableItemsChanged={this.onViewableItemsChanged}
    viewabilityConfig={{
        viewAreaCoveragePercentThreshold: 90
    }}

finally my this is how to calculate currentVisibleIndex please make sure to read viewabilityConfig

onViewableItemsChanged = ({ viewableItems, changed }) => {
    if (viewableItems && viewableItems.length > 0) {
        this.setState({ currentVisibleIndex: viewableItems[0].index });
    }
};

please let me know if this is helpful

Here is a possible solution using react-native-inviewport. This dependency is only a single index file that contains a component that has a callback when view is in the viewport. It could easily be modified to suit your needs.

I have constructed a very simple app that has a FlatList. The 11th item in the FlatList is a video. That should mean that the video is off the screen when the App renders so the viddeo won't be playing, once the video comes fully into the viewport it should then start playing.

App.js

import * as React from 'react';
import { Text, View, StyleSheet, FlatList } from 'react-native';
import Constants from 'expo-constants';
import VideoPlayer from './VideoPlayer';

export default class App extends React.Component {

  state = {
    data: [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20]
  }

  renderItem = ({item, index}) => {
    if (index === 10) {
      return <VideoPlayer />
    } else {
      return (
        <View style={{height: 100, backgroundColor: '#336699', justifyContent: 'center', alignItems: 'center'}}>
          <Text>{index}</Text>
        </View>
      )
    }
  }
  keyExtractor = (item, index) => `${index}`;

  render() {
    return (
      <View style={styles.container}>
        <FlatList
          data={this.state.data}
          renderItem={this.renderItem}
          keyExtractor={this.keyExtractor}
        />
      </View>
    );
  }
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
    paddingTop: Constants.statusBarHeight,
    backgroundColor: '#ecf0f1',
    padding: 8,
  }
});

VideoPlayer.js

This is a component that contains the Video component. The video is wrapped in the InViewPort component that has a callback function. The callback returns true when the component it surrounds is completely in the viewport and false when it is not fully in the viewport. The callback calls this.handlePlaying which in turn calls either this.playVideo or this.pauseVideo depending on the boolean value.

import React, {Component} from 'react';
import { View, StyleSheet } from 'react-native';
import { Video } from 'expo-av';
import InViewPort from './InViewPort';
//import InViewPort from 'react-native-inviewport; // this wouldn't work in the snack so I just copied the file and added it manually.

export default class VideoPlayer extends React.Component {

  pauseVideo = () => {
    if(this.video) {
      this.video.pauseAsync();
    }
  }

  playVideo = () => {
    if(this.video) {
      this.video.playAsync();
    }
  }

  handlePlaying = (isVisible) => {
    isVisible ? this.playVideo() : this.pauseVideo();
  }

  render() {
      return (
        <View style={styles.container}>
         <InViewPort onChange={this.handlePlaying}>
          <Video
            ref={ref => {this.video = ref}}
            source={{ uri: 'http://d23dyxeqlo5psv.cloudfront.net/big_buck_bunny.mp4' }}
            rate={1.0}
            volume={1.0}
            isMuted={false}
            resizeMode="cover"
            shouldPlay
            style={{ width: 300, height: 300 }}
          />
          </InViewPort>
        </View>
      )
  }  
}

const styles = StyleSheet.create({
  container: {
    justifyContent: 'center',
    alignItems: 'center'
  }
});

Here is a snack showing it working https://snack.expo.io/@andypandy/video-only-playing-when-in-viewport

I should point out that if the video is not fully in the viewport then it will not play. I am sure some tweaking could be done to react-native-inviewport so that it would play the video if it was partially in the viewport if that is what you wanted, perhaps by passing the height of the video to the InViewPort component.