356 lines
		
	
	
	
		
			11 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
			
		
		
	
	
			356 lines
		
	
	
	
		
			11 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
| import React, { PureComponent } from 'react';
 | |
| import { ScrollContainer } from 'react-router-scroll-4';
 | |
| import PropTypes from 'prop-types';
 | |
| import IntersectionObserverArticleContainer from '../containers/intersection_observer_article_container';
 | |
| import LoadMore from './load_more';
 | |
| import LoadPending from './load_pending';
 | |
| import IntersectionObserverWrapper from '../features/ui/util/intersection_observer_wrapper';
 | |
| import { throttle } from 'lodash';
 | |
| import { List as ImmutableList } from 'immutable';
 | |
| import classNames from 'classnames';
 | |
| import { attachFullscreenListener, detachFullscreenListener, isFullscreen } from '../features/ui/util/fullscreen';
 | |
| import LoadingIndicator from './loading_indicator';
 | |
| 
 | |
| const MOUSE_IDLE_DELAY = 300;
 | |
| 
 | |
| export default class ScrollableList extends PureComponent {
 | |
| 
 | |
|   static contextTypes = {
 | |
|     router: PropTypes.object,
 | |
|   };
 | |
| 
 | |
|   static propTypes = {
 | |
|     scrollKey: PropTypes.string.isRequired,
 | |
|     onLoadMore: PropTypes.func,
 | |
|     onLoadPending: PropTypes.func,
 | |
|     onScrollToTop: PropTypes.func,
 | |
|     onScroll: PropTypes.func,
 | |
|     trackScroll: PropTypes.bool,
 | |
|     shouldUpdateScroll: PropTypes.func,
 | |
|     isLoading: PropTypes.bool,
 | |
|     showLoading: PropTypes.bool,
 | |
|     hasMore: PropTypes.bool,
 | |
|     numPending: PropTypes.number,
 | |
|     prepend: PropTypes.node,
 | |
|     alwaysPrepend: PropTypes.bool,
 | |
|     emptyMessage: PropTypes.node,
 | |
|     children: PropTypes.node,
 | |
|     bindToDocument: PropTypes.bool,
 | |
|   };
 | |
| 
 | |
|   static defaultProps = {
 | |
|     trackScroll: true,
 | |
|   };
 | |
| 
 | |
|   state = {
 | |
|     fullscreen: null,
 | |
|     cachedMediaWidth: 250, // Default media/card width using default Mastodon theme
 | |
|   };
 | |
| 
 | |
|   intersectionObserverWrapper = new IntersectionObserverWrapper();
 | |
| 
 | |
|   handleScroll = throttle(() => {
 | |
|     if (this.node) {
 | |
|       const scrollTop = this.getScrollTop();
 | |
|       const scrollHeight = this.getScrollHeight();
 | |
|       const clientHeight = this.getClientHeight();
 | |
|       const offset = scrollHeight - scrollTop - clientHeight;
 | |
| 
 | |
|       if (400 > offset && this.props.onLoadMore && this.props.hasMore && !this.props.isLoading) {
 | |
|         this.props.onLoadMore();
 | |
|       }
 | |
| 
 | |
|       if (scrollTop < 100 && this.props.onScrollToTop) {
 | |
|         this.props.onScrollToTop();
 | |
|       } else if (this.props.onScroll) {
 | |
|         this.props.onScroll();
 | |
|       }
 | |
| 
 | |
|       if (!this.lastScrollWasSynthetic) {
 | |
|         // If the last scroll wasn't caused by setScrollTop(), assume it was
 | |
|         // intentional and cancel any pending scroll reset on mouse idle
 | |
|         this.scrollToTopOnMouseIdle = false;
 | |
|       }
 | |
|       this.lastScrollWasSynthetic = false;
 | |
|     }
 | |
|   }, 150, {
 | |
|     trailing: true,
 | |
|   });
 | |
| 
 | |
|   mouseIdleTimer = null;
 | |
|   mouseMovedRecently = false;
 | |
|   lastScrollWasSynthetic = false;
 | |
|   scrollToTopOnMouseIdle = false;
 | |
| 
 | |
|   _getScrollingElement = () => {
 | |
|     if (this.props.bindToDocument) {
 | |
|       return (document.scrollingElement || document.body);
 | |
|     } else {
 | |
|       return this.node;
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   setScrollTop = newScrollTop => {
 | |
|     if (this.getScrollTop() !== newScrollTop) {
 | |
|       this.lastScrollWasSynthetic = true;
 | |
| 
 | |
|       this._getScrollingElement().scrollTop = newScrollTop;
 | |
|     }
 | |
|   };
 | |
| 
 | |
|   clearMouseIdleTimer = () => {
 | |
|     if (this.mouseIdleTimer === null) {
 | |
|       return;
 | |
|     }
 | |
| 
 | |
|     clearTimeout(this.mouseIdleTimer);
 | |
|     this.mouseIdleTimer = null;
 | |
|   };
 | |
| 
 | |
|   handleMouseMove = throttle(() => {
 | |
|     // As long as the mouse keeps moving, clear and restart the idle timer.
 | |
|     this.clearMouseIdleTimer();
 | |
|     this.mouseIdleTimer = setTimeout(this.handleMouseIdle, MOUSE_IDLE_DELAY);
 | |
| 
 | |
|     if (!this.mouseMovedRecently && this.getScrollTop() === 0) {
 | |
|       // Only set if we just started moving and are scrolled to the top.
 | |
|       this.scrollToTopOnMouseIdle = true;
 | |
|     }
 | |
| 
 | |
|     // Save setting this flag for last, so we can do the comparison above.
 | |
|     this.mouseMovedRecently = true;
 | |
|   }, MOUSE_IDLE_DELAY / 2);
 | |
| 
 | |
|   handleWheel = throttle(() => {
 | |
|     this.scrollToTopOnMouseIdle = false;
 | |
|   }, 150, {
 | |
|     trailing: true,
 | |
|   });
 | |
| 
 | |
|   handleMouseIdle = () => {
 | |
|     if (this.scrollToTopOnMouseIdle) {
 | |
|       this.setScrollTop(0);
 | |
|     }
 | |
| 
 | |
|     this.mouseMovedRecently = false;
 | |
|     this.scrollToTopOnMouseIdle = false;
 | |
|   }
 | |
| 
 | |
|   componentDidMount () {
 | |
|     this.attachScrollListener();
 | |
|     this.attachIntersectionObserver();
 | |
| 
 | |
|     attachFullscreenListener(this.onFullScreenChange);
 | |
| 
 | |
|     // Handle initial scroll posiiton
 | |
|     this.handleScroll();
 | |
|   }
 | |
| 
 | |
|   getScrollPosition = () => {
 | |
|     if (this.node && (this.getScrollTop() > 0 || this.mouseMovedRecently)) {
 | |
|       return { height: this.getScrollHeight(), top: this.getScrollTop() };
 | |
|     } else {
 | |
|       return null;
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   getScrollTop = () => {
 | |
|     return this._getScrollingElement().scrollTop;
 | |
|   }
 | |
| 
 | |
|   getScrollHeight = () => {
 | |
|     return this._getScrollingElement().scrollHeight;
 | |
|   }
 | |
| 
 | |
|   getClientHeight = () => {
 | |
|     return this._getScrollingElement().clientHeight;
 | |
|   }
 | |
| 
 | |
|   updateScrollBottom = (snapshot) => {
 | |
|     const newScrollTop = this.getScrollHeight() - snapshot;
 | |
| 
 | |
|     this.setScrollTop(newScrollTop);
 | |
|   }
 | |
| 
 | |
|   getSnapshotBeforeUpdate (prevProps) {
 | |
|     const someItemInserted = React.Children.count(prevProps.children) > 0 &&
 | |
|       React.Children.count(prevProps.children) < React.Children.count(this.props.children) &&
 | |
|       this.getFirstChildKey(prevProps) !== this.getFirstChildKey(this.props);
 | |
|     const pendingChanged = (prevProps.numPending > 0) !== (this.props.numPending > 0);
 | |
| 
 | |
|     if (pendingChanged || someItemInserted && (this.getScrollTop() > 0 || this.mouseMovedRecently)) {
 | |
|       return this.getScrollHeight() - this.getScrollTop();
 | |
|     } else {
 | |
|       return null;
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   componentDidUpdate (prevProps, prevState, snapshot) {
 | |
|     // Reset the scroll position when a new child comes in in order not to
 | |
|     // jerk the scrollbar around if you're already scrolled down the page.
 | |
|     if (snapshot !== null) {
 | |
|       this.setScrollTop(this.getScrollHeight() - snapshot);
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   cacheMediaWidth = (width) => {
 | |
|     if (width && this.state.cachedMediaWidth !== width) {
 | |
|       this.setState({ cachedMediaWidth: width });
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   componentWillUnmount () {
 | |
|     this.clearMouseIdleTimer();
 | |
|     this.detachScrollListener();
 | |
|     this.detachIntersectionObserver();
 | |
| 
 | |
|     detachFullscreenListener(this.onFullScreenChange);
 | |
|   }
 | |
| 
 | |
|   onFullScreenChange = () => {
 | |
|     this.setState({ fullscreen: isFullscreen() });
 | |
|   }
 | |
| 
 | |
|   attachIntersectionObserver () {
 | |
|     let nodeOptions = {
 | |
|       root: this.node,
 | |
|       rootMargin: '300% 0px',
 | |
|     };
 | |
| 
 | |
|     this.intersectionObserverWrapper
 | |
|       .connect(this.props.bindToDocument ? {} : nodeOptions);
 | |
|   }
 | |
| 
 | |
|   detachIntersectionObserver () {
 | |
|     this.intersectionObserverWrapper.disconnect();
 | |
|   }
 | |
| 
 | |
|   attachScrollListener () {
 | |
|     if (this.props.bindToDocument) {
 | |
|       document.addEventListener('scroll', this.handleScroll);
 | |
|       document.addEventListener('wheel', this.handleWheel);
 | |
|     } else {
 | |
|       this.node.addEventListener('scroll', this.handleScroll);
 | |
|       this.node.addEventListener('wheel', this.handleWheel);
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   detachScrollListener () {
 | |
|     if (this.props.bindToDocument) {
 | |
|       document.removeEventListener('scroll', this.handleScroll);
 | |
|       document.removeEventListener('wheel', this.handleWheel);
 | |
|     } else {
 | |
|       this.node.removeEventListener('scroll', this.handleScroll);
 | |
|       this.node.removeEventListener('wheel', this.handleWheel);
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   getFirstChildKey (props) {
 | |
|     const { children } = props;
 | |
|     let firstChild     = children;
 | |
| 
 | |
|     if (children instanceof ImmutableList) {
 | |
|       firstChild = children.get(0);
 | |
|     } else if (Array.isArray(children)) {
 | |
|       firstChild = children[0];
 | |
|     }
 | |
| 
 | |
|     return firstChild && firstChild.key;
 | |
|   }
 | |
| 
 | |
|   setRef = (c) => {
 | |
|     this.node = c;
 | |
|   }
 | |
| 
 | |
|   handleLoadMore = e => {
 | |
|     e.preventDefault();
 | |
|     this.props.onLoadMore();
 | |
|   }
 | |
| 
 | |
|   handleLoadPending = e => {
 | |
|     e.preventDefault();
 | |
|     this.props.onLoadPending();
 | |
|     // Prevent the weird scroll-jumping behavior, as we explicitly don't want to
 | |
|     // scroll to top, and we know the scroll height is going to change
 | |
|     this.scrollToTopOnMouseIdle = false;
 | |
|     this.lastScrollWasSynthetic = false;
 | |
|     this.clearMouseIdleTimer();
 | |
|     this.mouseIdleTimer = setTimeout(this.handleMouseIdle, MOUSE_IDLE_DELAY);
 | |
|     this.mouseMovedRecently = true;
 | |
|   }
 | |
| 
 | |
|   render () {
 | |
|     const { children, scrollKey, trackScroll, shouldUpdateScroll, showLoading, isLoading, hasMore, numPending, prepend, alwaysPrepend, emptyMessage, onLoadMore } = this.props;
 | |
|     const { fullscreen } = this.state;
 | |
|     const childrenCount = React.Children.count(children);
 | |
| 
 | |
|     const loadMore     = (hasMore && onLoadMore) ? <LoadMore visible={!isLoading} onClick={this.handleLoadMore} /> : null;
 | |
|     const loadPending  = (numPending > 0) ? <LoadPending count={numPending} onClick={this.handleLoadPending} /> : null;
 | |
|     let scrollableArea = null;
 | |
| 
 | |
|     if (showLoading) {
 | |
|       scrollableArea = (
 | |
|         <div className='scrollable scrollable--flex' ref={this.setRef}>
 | |
|           <div role='feed' className='item-list'>
 | |
|             {prepend}
 | |
|           </div>
 | |
| 
 | |
|           <div className='scrollable__append'>
 | |
|             <LoadingIndicator />
 | |
|           </div>
 | |
|         </div>
 | |
|       );
 | |
|     } else if (isLoading || childrenCount > 0 || numPending > 0 || hasMore || !emptyMessage) {
 | |
|       scrollableArea = (
 | |
|         <div className={classNames('scrollable', { fullscreen })} ref={this.setRef} onMouseMove={this.handleMouseMove}>
 | |
|           <div role='feed' className='item-list'>
 | |
|             {prepend}
 | |
| 
 | |
|             {loadPending}
 | |
| 
 | |
|             {React.Children.map(this.props.children, (child, index) => (
 | |
|               <IntersectionObserverArticleContainer
 | |
|                 key={child.key}
 | |
|                 id={child.key}
 | |
|                 index={index}
 | |
|                 listLength={childrenCount}
 | |
|                 intersectionObserverWrapper={this.intersectionObserverWrapper}
 | |
|                 saveHeightKey={trackScroll ? `${this.context.router.route.location.key}:${scrollKey}` : null}
 | |
|               >
 | |
|                 {React.cloneElement(child, {
 | |
|                   getScrollPosition: this.getScrollPosition,
 | |
|                   updateScrollBottom: this.updateScrollBottom,
 | |
|                   cachedMediaWidth: this.state.cachedMediaWidth,
 | |
|                   cacheMediaWidth: this.cacheMediaWidth,
 | |
|                 })}
 | |
|               </IntersectionObserverArticleContainer>
 | |
|             ))}
 | |
| 
 | |
|             {loadMore}
 | |
|           </div>
 | |
|         </div>
 | |
|       );
 | |
|     } else {
 | |
|       scrollableArea = (
 | |
|         <div className={classNames('scrollable scrollable--flex', { fullscreen })} ref={this.setRef}>
 | |
|           {alwaysPrepend && prepend}
 | |
| 
 | |
|           <div className='empty-column-indicator'>
 | |
|             {emptyMessage}
 | |
|           </div>
 | |
|         </div>
 | |
|       );
 | |
|     }
 | |
| 
 | |
|     if (trackScroll) {
 | |
|       return (
 | |
|         <ScrollContainer scrollKey={scrollKey} shouldUpdateScroll={shouldUpdateScroll}>
 | |
|           {scrollableArea}
 | |
|         </ScrollContainer>
 | |
|       );
 | |
|     } else {
 | |
|       return scrollableArea;
 | |
|     }
 | |
|   }
 | |
| 
 | |
| }
 |