chinwagsocial/app/javascript/mastodon/components/status_list.js
Sorin Davidoi 8e4d1cba00 Lazy load toots using IntersectionObserver (#3191)
* refactor(components/status_list): Lazy load using IntersectionObserver

* refactor(components/status_list): Avoid setState bottleneck

* refactor(components/status_list): Update state correctly

* fix(components/status): Render if isIntersecting is undefined

* refactor(components/status): Recycle timeout

* refactor(components/status): Reduce animation duration

* refactor(components/status): Use requestIdleCallback

* chore: Split polyfill bundles

* refactor(components/status_list): Increase rootMargin to 300%

* fix(components/status): Check if onRef is not defined

* chore: Add note about polyfill bundle splitting

* fix(components/status): Reduce animation duration to 0.3 seconds
2017-05-24 17:55:00 +02:00

172 lines
4.6 KiB
JavaScript

import React from 'react';
import ImmutablePropTypes from 'react-immutable-proptypes';
import { ScrollContainer } from 'react-router-scroll';
import PropTypes from 'prop-types';
import StatusContainer from '../containers/status_container';
import LoadMore from './load_more';
import ImmutablePureComponent from 'react-immutable-pure-component';
class StatusList extends ImmutablePureComponent {
static propTypes = {
scrollKey: PropTypes.string.isRequired,
statusIds: ImmutablePropTypes.list.isRequired,
onScrollToBottom: PropTypes.func,
onScrollToTop: PropTypes.func,
onScroll: PropTypes.func,
shouldUpdateScroll: PropTypes.func,
isLoading: PropTypes.bool,
isUnread: PropTypes.bool,
hasMore: PropTypes.bool,
prepend: PropTypes.node,
emptyMessage: PropTypes.node,
};
static defaultProps = {
trackScroll: true,
};
state = {
isIntersecting: [{ }],
}
statusRefQueue = []
handleScroll = (e) => {
const { scrollTop, scrollHeight, clientHeight } = e.target;
const offset = scrollHeight - scrollTop - clientHeight;
this._oldScrollPosition = scrollHeight - scrollTop;
if (250 > offset && this.props.onScrollToBottom && !this.props.isLoading) {
this.props.onScrollToBottom();
} else if (scrollTop < 100 && this.props.onScrollToTop) {
this.props.onScrollToTop();
} else if (this.props.onScroll) {
this.props.onScroll();
}
}
componentDidMount () {
this.attachScrollListener();
this.attachIntersectionObserver();
}
componentDidUpdate (prevProps) {
if ((prevProps.statusIds.size < this.props.statusIds.size && prevProps.statusIds.first() !== this.props.statusIds.first() && !!this._oldScrollPosition) && this.node.scrollTop > 0) {
this.node.scrollTop = this.node.scrollHeight - this._oldScrollPosition;
}
}
componentWillUnmount () {
this.detachScrollListener();
this.detachIntersectionObserver();
}
attachIntersectionObserver () {
const onIntersection = (entries) => {
this.setState(state => {
const isIntersecting = { };
entries.forEach(entry => {
const statusId = entry.target.getAttribute('data-id');
state.isIntersecting[0][statusId] = entry.isIntersecting;
});
return { isIntersecting: [state.isIntersecting[0]] };
});
};
const options = {
root: this.node,
rootMargin: '300% 0px',
};
this.intersectionObserver = new IntersectionObserver(onIntersection, options);
if (this.statusRefQueue.length) {
this.statusRefQueue.forEach(node => this.intersectionObserver.observe(node));
this.statusRefQueue = [];
}
}
detachIntersectionObserver () {
this.intersectionObserver.disconnect();
}
attachScrollListener () {
this.node.addEventListener('scroll', this.handleScroll);
}
detachScrollListener () {
this.node.removeEventListener('scroll', this.handleScroll);
}
setRef = (c) => {
this.node = c;
}
handleStatusRef = (node) => {
if (node && this.intersectionObserver) {
const statusId = node.getAttribute('data-id');
this.intersectionObserver.observe(node);
} else {
this.statusRefQueue.push(node);
}
}
handleLoadMore = (e) => {
e.preventDefault();
this.props.onScrollToBottom();
}
render () {
const { statusIds, onScrollToBottom, scrollKey, shouldUpdateScroll, isLoading, isUnread, hasMore, prepend, emptyMessage } = this.props;
const isIntersecting = this.state.isIntersecting[0];
let loadMore = null;
let scrollableArea = null;
let unread = null;
if (!isLoading && statusIds.size > 0 && hasMore) {
loadMore = <LoadMore onClick={this.handleLoadMore} />;
}
if (isUnread) {
unread = <div className='status-list__unread-indicator' />;
}
if (isLoading || statusIds.size > 0 || !emptyMessage) {
scrollableArea = (
<div className='scrollable' ref={this.setRef}>
{unread}
<div className='status-list'>
{prepend}
{statusIds.map((statusId) => {
return <StatusContainer key={statusId} id={statusId} isIntersecting={isIntersecting[statusId]} onRef={this.handleStatusRef} />;
})}
{loadMore}
</div>
</div>
);
} else {
scrollableArea = (
<div className='empty-column-indicator' ref={this.setRef}>
{emptyMessage}
</div>
);
}
return (
<ScrollContainer scrollKey={scrollKey} shouldUpdateScroll={shouldUpdateScroll}>
{scrollableArea}
</ScrollContainer>
);
}
}
export default StatusList;