Various fixes to scrollable lists and media gallery (#9501)

* Always use the scrollable class for the ScrollList component

Fixes #9499 as well as empty timelines' scrollbar “blinking”
between loading state and empty state.

* Do not display empty message when the list is known to have more elements

Fixes #9500

* Fix LoadMore usage in account media gallery

(Even though that codepath is probably never actually used…)

* Make account media gallery more consistent with account timeline

Fixes #9498

Display “load more” more consistently, add a loading indicator on first load.

* Fix “load more” button when no data has been fetched

5 files changed, 18 insertions, 16 deletions

diff --git a/app/javascript/mastodon/components/scrollable_list.js b/app/javascript/mastodon/components/scrollable_list.js
index ab4e7d59c..774c8835d 100644
--- a/app/javascript/mastodon/components/scrollable_list.js
+++ b/app/javascript/mastodon/components/scrollable_list.js
@@ -30,7 +30,6 @@ export default class ScrollableList extends PureComponent {
     hasMore: PropTypes.bool,
     prepend: PropTypes.node,
     alwaysPrepend: PropTypes.bool,
-    alwaysShowScrollbar: PropTypes.bool,
     emptyMessage: PropTypes.node,
     children: PropTypes.node,
   };
@@ -206,11 +205,11 @@ export default class ScrollableList extends PureComponent {
   }
 
   render () {
-    const { children, scrollKey, trackScroll, shouldUpdateScroll, showLoading, isLoading, hasMore, prepend, alwaysPrepend, alwaysShowScrollbar, emptyMessage, onLoadMore } = this.props;
+    const { children, scrollKey, trackScroll, shouldUpdateScroll, showLoading, isLoading, hasMore, prepend, alwaysPrepend, emptyMessage, onLoadMore } = this.props;
     const { fullscreen } = this.state;
     const childrenCount = React.Children.count(children);
 
-    const loadMore     = (hasMore && childrenCount > 0 && onLoadMore) ? <LoadMore visible={!isLoading} onClick={this.handleLoadMore} /> : null;
+    const loadMore     = (hasMore && onLoadMore) ? <LoadMore visible={!isLoading} onClick={this.handleLoadMore} /> : null;
     let scrollableArea = null;
 
     if (showLoading) {
@@ -225,7 +224,7 @@ export default class ScrollableList extends PureComponent {
           </div>
         </div>
       );
-    } else if (isLoading || childrenCount > 0 || !emptyMessage) {
+    } else if (isLoading || childrenCount > 0 || hasMore || !emptyMessage) {
       scrollableArea = (
         <div className={classNames('scrollable', { fullscreen })} ref={this.setRef} onMouseMove={this.handleMouseMove}>
           <div role='feed' className='item-list'>
@@ -249,10 +248,8 @@ export default class ScrollableList extends PureComponent {
         </div>
       );
     } else {
-      const scrollable = alwaysShowScrollbar;
-
       scrollableArea = (
-        <div className={classNames({ scrollable, fullscreen })} ref={this.setRef} style={{ flex: '1 1 auto', display: 'flex', flexDirection: 'column' }}>
+        <div className={classNames('scrollable scrollable--flex', { fullscreen })} ref={this.setRef}>
           {alwaysPrepend && prepend}
 
           <div className='empty-column-indicator'>
diff --git a/app/javascript/mastodon/components/status_list.js b/app/javascript/mastodon/components/status_list.js
index 01cc05661..e417f9a2b 100644
--- a/app/javascript/mastodon/components/status_list.js
+++ b/app/javascript/mastodon/components/status_list.js
@@ -55,7 +55,7 @@ export default class StatusList extends ImmutablePureComponent {
   }
 
   handleLoadOlder = debounce(() => {
-    this.props.onLoadMore(this.props.statusIds.last());
+    this.props.onLoadMore(this.props.statusIds.size > 0 ? this.props.statusIds.last() : undefined);
   }, 300, { leading: true })
 
   _selectChild (index) {
diff --git a/app/javascript/mastodon/features/account_gallery/index.js b/app/javascript/mastodon/features/account_gallery/index.js
index 32cb5ebdc..0d66868ed 100644
--- a/app/javascript/mastodon/features/account_gallery/index.js
+++ b/app/javascript/mastodon/features/account_gallery/index.js
@@ -36,7 +36,7 @@ class LoadMoreMedia extends ImmutablePureComponent {
     return (
       <LoadMore
         disabled={this.props.disabled}
-        onLoadMore={this.handleLoadMore}
+        onClick={this.handleLoadMore}
       />
     );
   }
@@ -68,7 +68,7 @@ class AccountGallery extends ImmutablePureComponent {
 
   handleScrollToBottom = () => {
     if (this.props.hasMore) {
-      this.handleLoadMore(this.props.medias.last().getIn(['status', 'id']));
+      this.handleLoadMore(this.props.medias.size > 0 ? this.props.medias.last().getIn(['status', 'id']) : undefined);
     }
   }
 
@@ -103,8 +103,8 @@ class AccountGallery extends ImmutablePureComponent {
       );
     }
 
-    if (!isLoading && medias.size > 0 && hasMore) {
-      loadOlder = <LoadMore onClick={this.handleLoadOlder} />;
+    if (hasMore) {
+      loadOlder = <LoadMore visible={!isLoading} onClick={this.handleLoadOlder} />;
     }
 
     return (
@@ -112,14 +112,15 @@ class AccountGallery extends ImmutablePureComponent {
         <ColumnBackButton />
 
         <ScrollContainer scrollKey='account_gallery' shouldUpdateScroll={shouldUpdateScroll}>
-          <div className='scrollable' onScroll={this.handleScroll}>
+          <div className='scrollable scrollable--flex' onScroll={this.handleScroll}>
             <HeaderContainer accountId={this.props.params.accountId} />
 
-            <div className='account-gallery__container'>
+            <div role='feed' className='account-gallery__container'>
               {medias.map((media, index) => media === null ? (
                 <LoadMoreMedia
                   key={'more:' + medias.getIn(index + 1, 'id')}
                   maxId={index > 0 ? medias.getIn(index - 1, 'id') : null}
+                  onLoadMore={this.handleLoadMore}
                 />
               ) : (
                 <MediaItem
@@ -129,6 +130,12 @@ class AccountGallery extends ImmutablePureComponent {
               ))}
               {loadOlder}
             </div>
+
+            {isLoading && medias.size === 0 && (
+              <div className='scrollable__append'>
+                <LoadingIndicator />
+              </div>
+            )}
           </div>
         </ScrollContainer>
       </Column>
diff --git a/app/javascript/mastodon/features/followers/index.js b/app/javascript/mastodon/features/followers/index.js
index b9ca7f3dd..ce56f270c 100644
--- a/app/javascript/mastodon/features/followers/index.js
+++ b/app/javascript/mastodon/features/followers/index.js
@@ -73,7 +73,6 @@ class Followers extends ImmutablePureComponent {
           shouldUpdateScroll={shouldUpdateScroll}
           prepend={<HeaderContainer accountId={this.props.params.accountId} hideTabs />}
           alwaysPrepend
-          alwaysShowScrollbar
           emptyMessage={emptyMessage}
         >
           {accountIds.map(id =>
diff --git a/app/javascript/mastodon/features/following/index.js b/app/javascript/mastodon/features/following/index.js
index b3e160240..bda0438a0 100644
--- a/app/javascript/mastodon/features/following/index.js
+++ b/app/javascript/mastodon/features/following/index.js
@@ -73,7 +73,6 @@ class Following extends ImmutablePureComponent {
           shouldUpdateScroll={shouldUpdateScroll}
           prepend={<HeaderContainer accountId={this.props.params.accountId} hideTabs />}
           alwaysPrepend
-          alwaysShowScrollbar
           emptyMessage={emptyMessage}
         >
           {accountIds.map(id =>