React Native : Bad performance animating the height of a view using react-native-reanimated

Question

Animating the height of a view when scrolling through a list is very slow and choppy, it's work fine for IOS, but not for Android :

import * as React from "react";
import { StyleSheet, Text } from "react-native";
import Animated from "react-native-reanimated";
const { Value, View, ScrollView, interpolate, Extrapolate } = Animated;
const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: "black"
  },
  listView: {
    flex: 1
  }
});

const IMAGE_MIN_HEIGHT = 300;

export default () => {
  const animation = new Value(0);

  const height = interpolate(animation, {
    inputRange: [0, 125],
    outputRange: [IMAGE_MIN_HEIGHT, 125],
    extrapolate: Extrapolate.CLAMP
  });

  return (
    <View style={styles.container}>
      <View
        style={{
          backgroundColor: "red",
          height: height,
          width: "100%"
        }}
      ></View>
      <ScrollView
        onScroll={Animated.event([
          {
            nativeEvent: {
              contentOffset: {
                y: animation
              }
            }
          }
        ])}
        scrollEventThrottle={1}
        style={[styles.listView]}
      >
        {[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0].map((elem, index) => (
          <View
            style={{ width: "100%", height: 100, marginBottom: 20 }}
            key={index}
          >
            <Text style={{ color: "white", fontSize: 30 }}>{elem}</Text>
          </View>
        ))}
      </ScrollView>
    </View>
  );
};

Is there anything that can be done to make it smoother?

Answer 1

the solution is to set Header position to absolute, i don't know why but it's working fine :

import * as React from "react";
import { StyleSheet, Text, Platform } from "react-native";
import Animated from "react-native-reanimated";
const { Value, View, ScrollView, interpolate, Extrapolate } = Animated;
const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: "black"
  },
  listView: {
    flex: 1
  }
});

const IMAGE_MIN_HEIGHT = 300;

export default () => {
  const animation = new Value(0);

  const height = interpolate(animation, {
    inputRange: [0, 125],
    outputRange: [IMAGE_MIN_HEIGHT, 125],
    extrapolate: Extrapolate.CLAMP
  });

  return (
    <View style={styles.container}>
      <ScrollView
        contentContainerStyle={{ paddingTop: IMAGE_MIN_HEIGHT }}
        onScroll={Animated.event([
          {
            nativeEvent: {
              contentOffset: {
                y: animation
              }
            }
          }
        ])}
        scrollEventThrottle={1}
        style={[styles.listView]}
      >
        {[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0].map((elem, index) => (
          <View
            style={{ width: "100%", height: 100, marginBottom: 20 }}
            key={index}
          >
            <Text style={{ color: "white", fontSize: 30 }}>{elem}</Text>
          </View>
        ))}
      </ScrollView>

      <View
        style={{
          backgroundColor: "red",
          height: height,
          width: "100%",
          position: "absolute",
          top: Platform.OS == "ios" ? 20 : 0,
          left: 0,
          right: 0
        }}
      ></View>
    </View>
  );
};