import rafSchedule from 'raf-schd';class ScrollListener extends React.Component {
  constructor(props) {
    super(props);
    this.handleScroll = this.handleScroll.bind(this);    // Create a new function to schedule updates.
    this.scheduleUpdate = rafSchedule(
      point => this.props.onScroll(point)
    );
  }
  handleScroll(e) {    // When we receive a scroll event, schedule an update.    // If we receive many updates within a frame, we'll only publish the latest value.
    this.scheduleUpdate({ x: e.clientX, y: e.clientY });   // queue a call
  }
  componentWillUnmount() {    // Cancel any pending updates since we're unmounting.
    this.scheduleUpdate.cancel();
  }
  render() {
    return (
      <div style={{ overflow: 'scroll' }}
  onScroll={this.handleScroll}>
        <img src="/my-huge-image.jpg" />
      </div>
    );
  }}