| import * as React from 'react'; |
| import { withRouter } from 'react-router-dom'; |
| import debounceFn from 'debounce'; |
|
|
| type Props = { |
| scrollCaptureDebounce: number, |
| scrollSyncDebounce: number, |
| scrollSyncAttemptLimit: number, |
| children: React$Node, |
| history: Object, |
| location: Object, |
| onLocationChange: Function, |
| }; |
|
|
| class ScrollManager extends React.Component<Props> { |
| static defaultProps = { |
| scrollCaptureDebounce: 50, |
| scrollSyncDebounce: 100, |
| scrollSyncAttemptLimit: 5, |
| }; |
|
|
| constructor(props) { |
| super(props); |
|
|
| this.scrollSyncData = { |
| x: 0, |
| y: 0, |
| attemptsRemaining: props.scrollSyncAttemptLimit, |
| }; |
|
|
| const scrollCapture = () => { |
| requestAnimationFrame(() => { |
| const { pageXOffset, pageYOffset } = window; |
| const { pathname } = this.props.location; |
|
|
| |
| |
| const historyState = window.history.state || {}; |
| const { state = {} } = historyState; |
| if ( |
| !state.scroll || |
| state.scroll.x !== pageXOffset || |
| state.scroll.y !== pageYOffset |
| ) { |
| window.history.replaceState( |
| { |
| ...historyState, |
| state: { ...state, scroll: { x: pageXOffset, y: pageYOffset } }, |
| }, |
| null, |
| pathname |
| ); |
| } |
| }); |
| }; |
|
|
| const _scrollSync = () => { |
| requestAnimationFrame(() => { |
| const { x, y, attemptsRemaining } = this.scrollSyncData; |
|
|
| if (attemptsRemaining < 1) { |
| return; |
| } |
|
|
| const { pageXOffset, pageYOffset } = window; |
| if ( |
| y < window.document.body.scrollHeight && |
| (x !== pageXOffset || y !== pageYOffset) |
| ) { |
| window.scrollTo(x, y); |
| this.scrollSyncData.attemptsRemaining = attemptsRemaining - 1; |
| _scrollSync(); |
| } |
| }); |
| }; |
|
|
| const scrollSync = (x = 0, y = 0) => { |
| this.scrollSyncData = { |
| x, |
| y, |
| attemptsRemaining: this.props.scrollSyncAttemptLimit, |
| }; |
| _scrollSync(); |
| }; |
|
|
| this.debouncedScroll = debounceFn( |
| scrollCapture, |
| props.scrollCaptureDebounce |
| ); |
| this.debouncedScrollSync = debounceFn(scrollSync, props.scrollSyncDebounce); |
| } |
|
|
| componentWillMount() { |
| const { location, onLocationChange } = this.props; |
| if (onLocationChange) { |
| onLocationChange(location); |
| } |
| } |
|
|
| componentDidMount() { |
| this.onPop(this.props); |
| window.addEventListener('scroll', this.debouncedScroll, { passive: true }); |
| } |
|
|
| componentWillUnmount() { |
| this.scrollSyncPending = false; |
| window.removeEventListener('scroll', this.debouncedScroll, { |
| passive: true, |
| }); |
| } |
|
|
| componentWillReceiveProps(nextProps) { |
| switch (nextProps.history.action) { |
| case 'PUSH': |
| case 'REPLACE': |
| this.onPush(); |
| break; |
| case 'POP': |
| this.onPop(nextProps); |
| break; |
| default: |
| console.warn( |
| `Unrecognized location change action! "${nextProps.history.action}"` |
| ); |
| } |
| if (nextProps.onLocationChange) { |
| nextProps.onLocationChange(nextProps.location); |
| } |
| } |
|
|
| onPush() { |
| this.debouncedScrollSync(0, 0); |
| } |
|
|
| onPop({ location: { state = {} } }) { |
| |
| const { x = 0, y = 0 } = state.scroll || {}; |
| this.debouncedScrollSync(x, y); |
| } |
|
|
| render() { |
| return this.props.children; |
| } |
| } |
|
|
| export default withRouter(ScrollManager); |
|
|
