scroll-indicator-1.jsx

export default Example = () => {
  const [contentOffset, setContentOffset] = React.useState({ x: 0, y: 0 });
  const [contentSize, setContentSize] = React.useState(0);
  
  return(
    <ScrollView
      onScroll={e => {
        setContentOffset(e.nativeEvent.contentOffset);
      }}
      onContentSizeChange={(_, height) => {
        setContentSize(height);
      }}
    >...
    </ScrollView>
  );
}