insights-js/examples/example-expo-53/components/ParallaxScrollView.tsx

import type { PropsWithChildren, ReactElement } from 'react'
import { StyleSheet } from 'react-native'
import Animated, { interpolate, useAnimatedRef, useAnimatedStyle, useScrollViewOffset } from 'react-native-reanimated'

import { ThemedView } from '@/components/ThemedView'
import { useBottomTabOverflow } from '@/components/ui/TabBarBackground'
import { useColorScheme } from '@/hooks/useColorScheme'

const HEADER_HEIGHT = 250

type Props = PropsWithChildren<{
  headerImage: ReactElement
  headerBackgroundColor: { dark: string; light: string }
}>

export default function ParallaxScrollView({ children, headerImage, headerBackgroundColor }: Props) {
  const colorScheme = useColorScheme() ?? 'light'
  const scrollRef = useAnimatedRef<Animated.ScrollView>()
  const scrollOffset = useScrollViewOffset(scrollRef)
  const bottom = useBottomTabOverflow()
  const headerAnimatedStyle = useAnimatedStyle(() => {
    return {
      transform: [
        {
          translateY: interpolate(
            scrollOffset.value,
            [-HEADER_HEIGHT, 0, HEADER_HEIGHT],
            [-HEADER_HEIGHT / 2, 0, HEADER_HEIGHT * 0.75]
          ),
        },
        {
          scale: interpolate(scrollOffset.value, [-HEADER_HEIGHT, 0, HEADER_HEIGHT], [2, 1, 1]),
        },
      ],
    }
  })

  return (
    <ThemedView style={styles.container}>
      <Animated.ScrollView
        ref={scrollRef}
        scrollEventThrottle={16}
        scrollIndicatorInsets={{ bottom }}
        contentContainerStyle={{ paddingBottom: bottom }}
      >
        <Animated.View
          style={[styles.header, { backgroundColor: headerBackgroundColor[colorScheme] }, headerAnimatedStyle]}
        >
          {headerImage}
        </Animated.View>
        <ThemedView style={styles.content}>{children}</ThemedView>
      </Animated.ScrollView>
    </ThemedView>
  )
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
  },
  header: {
    height: HEADER_HEIGHT,
    overflow: 'hidden',
  },
  content: {
    flex: 1,
    padding: 32,
    gap: 16,
    overflow: 'hidden',
  },
})