1 files changed, 67 insertions, 15 deletions
diff --git a/app/javascript/flavours/glitch/components/scrollable_list.js b/app/javascript/flavours/glitch/components/scrollable_list.js
index 462185bbc..c022290a4 100644
--- a/app/javascript/flavours/glitch/components/scrollable_list.js
+++ b/app/javascript/flavours/glitch/components/scrollable_list.js
@@ -3,6 +3,7 @@ import { ScrollContainer } from 'react-router-scroll-4';
 import PropTypes from 'prop-types';
 import IntersectionObserverArticleContainer from 'flavours/glitch/containers/intersection_observer_article_container';
 import LoadMore from './load_more';
+import LoadPending from './load_pending';
 import IntersectionObserverWrapper from 'flavours/glitch/util/intersection_observer_wrapper';
 import { throttle } from 'lodash';
 import { List as ImmutableList } from 'immutable';
@@ -21,6 +22,7 @@ export default class ScrollableList extends PureComponent {
   static propTypes = {
     scrollKey: PropTypes.string.isRequired,
     onLoadMore: PropTypes.func,
+    onLoadPending: PropTypes.func,
     onScrollToTop: PropTypes.func,
     onScroll: PropTypes.func,
     trackScroll: PropTypes.bool,
@@ -28,10 +30,12 @@ export default class ScrollableList extends PureComponent {
     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 = {
@@ -47,7 +51,9 @@ export default class ScrollableList extends PureComponent {
 
   handleScroll = throttle(() => {
     if (this.node) {
-      const { scrollTop, scrollHeight, clientHeight } = 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) {
@@ -77,9 +83,14 @@ export default class ScrollableList extends PureComponent {
   scrollToTopOnMouseIdle = false;
 
   setScrollTop = newScrollTop => {
-    if (this.node.scrollTop !== newScrollTop) {
+    if (this.getScrollTop() !== newScrollTop) {
       this.lastScrollWasSynthetic = true;
-      this.node.scrollTop = newScrollTop;
+
+      if (this.props.bindToDocument) {
+        document.scrollingElement.scrollTop = newScrollTop;
+      } else {
+        this.node.scrollTop = newScrollTop;
+      }
     }
   };
 
@@ -97,7 +108,7 @@ export default class ScrollableList extends PureComponent {
     this.mouseIdleTimer =
       setTimeout(this.handleMouseIdle, MOUSE_IDLE_DELAY);
 
-    if (!this.mouseMovedRecently && this.node.scrollTop === 0) {
+    if (!this.mouseMovedRecently && this.getScrollTop() === 0) {
       // Only set if we just started moving and are scrolled to the top.
       this.scrollToTopOnMouseIdle = true;
     }
@@ -129,15 +140,27 @@ export default class ScrollableList extends PureComponent {
   }
 
   getScrollPosition = () => {
-    if (this.node && (this.node.scrollTop > 0 || this.mouseMovedRecently)) {
-      return {height: this.node.scrollHeight, top: this.node.scrollTop};
+    if (this.node && (this.getScrollTop() > 0 || this.mouseMovedRecently)) {
+      return { height: this.getScrollHeight(), top: this.getScrollTop() };
     } else {
       return null;
     }
   }
 
+  getScrollTop = () => {
+    return this.props.bindToDocument ? document.scrollingElement.scrollTop : this.node.scrollTop;
+  }
+
+  getScrollHeight = () => {
+    return this.props.bindToDocument ? document.scrollingElement.scrollHeight : this.node.scrollHeight;
+  }
+
+  getClientHeight = () => {
+    return this.props.bindToDocument ? document.scrollingElement.clientHeight : this.node.clientHeight;
+  }
+
   updateScrollBottom = (snapshot) => {
-    const newScrollTop = this.node.scrollHeight - snapshot;
+    const newScrollTop = this.getScrollHeight() - snapshot;
 
     this.setScrollTop(newScrollTop);
   }
@@ -150,8 +173,10 @@ export default class ScrollableList extends PureComponent {
     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);
-    if (someItemInserted && (this.node.scrollTop > 0 || this.mouseMovedRecently)) {
-      return this.node.scrollHeight - this.node.scrollTop;
+    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;
     }
@@ -160,7 +185,9 @@ export default class ScrollableList extends PureComponent {
   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.updateScrollBottom(snapshot);
+    if (snapshot !== null) {
+      this.updateScrollBottom(snapshot);
+    }
   }
 
   componentWillUnmount () {
@@ -186,13 +213,23 @@ export default class ScrollableList extends PureComponent {
   }
 
   attachScrollListener () {
-    this.node.addEventListener('scroll', this.handleScroll);
-    this.node.addEventListener('wheel', this.handleWheel);
+    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 () {
-    this.node.removeEventListener('scroll', this.handleScroll);
-    this.node.removeEventListener('wheel', this.handleWheel);
+    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) {
@@ -222,12 +259,25 @@ export default class ScrollableList extends PureComponent {
     return !(location.state && location.state.mastodonModalOpen);
   }
 
+  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, prepend, alwaysPrepend, emptyMessage, onLoadMore } = this.props;
+    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) {
@@ -248,6 +298,8 @@ export default class ScrollableList extends PureComponent {
           <div role='feed' className='item-list'>
             {prepend}
 
+            {loadPending}
+
             {React.Children.map(this.props.children, (child, index) => (
               <IntersectionObserverArticleContainer
                 key={child.key}