Fix chat scroll

ui/component/livestreamChatLayout/view.jsx

@@ -74,15 +74,9 @@ export default function LivestreamChatLayout(props: Props) {
   const allCommentsElem = document.querySelectorAll('.livestream__comment');
   const lastCommentElem = allCommentsElem && allCommentsElem[allCommentsElem.length - 1];
   const minScrollPos =
-    discussionElement && lastCommentElem && discussionElement.scrollHeight - lastCommentElem.offsetHeight;
+    discussionElement && lastCommentElem && discussionElement.scrollHeight - lastCommentElem.offsetHeight * 2;
   const minOffset = discussionElement && minScrollPos && discussionElement.scrollHeight - minScrollPos;
 
-  const restoreScrollPos = React.useCallback(() => {
-    if (discussionElement) discussionElement.scrollTop = !isMobile ? 0 : discussionElement.scrollHeight;
-  }, [discussionElement, isMobile]);
-
-  const commentsRef = React.createRef();
-
   const [viewMode, setViewMode] = React.useState(VIEW_MODES.CHAT);
   const [scrollPos, setScrollPos] = React.useState(0);
   const [showPinned, setShowPinned] = React.useState(true);
@@ -91,6 +85,7 @@ export default function LivestreamChatLayout(props: Props) {
   const [chatHidden, setChatHidden] = React.useState(false);
   const [didInitialScroll, setDidInitialScroll] = React.useState(false);
   const [bottomScrollTop, setBottomScrollTop] = React.useState(0);
+  const [inputDrawerOpen, setInputDrawerOpen] = React.useState(false);
 
   const recentScrollPos = isMobile ? (bottomScrollTop > 0 && minOffset ? bottomScrollTop - minOffset : 0) : 0;
   const claimId = claim && claim.claim_id;
@@ -98,6 +93,18 @@ export default function LivestreamChatLayout(props: Props) {
   const commentsLength = commentsToDisplay && commentsToDisplay.length;
   const pinnedComment = pinnedComments.length > 0 ? pinnedComments[0] : null;
   const { superChatsChannelUrls, superChatsFiatAmount, superChatsLBCAmount } = getTipValues(superChatsByAmount);
+  const hasRecentComments = Boolean(
+    scrollPos && (!isMobile || recentScrollPos) && scrollPos < recentScrollPos && viewMode === VIEW_MODES.CHAT
+  );
+
+  const restoreScrollPos = React.useCallback(() => {
+    if (discussionElement) {
+      discussionElement.scrollTop = !isMobile ? 0 : discussionElement.scrollHeight;
+      setBottomScrollTop(discussionElement.scrollTop);
+    }
+  }, [discussionElement, isMobile]);
+
+  const commentsRef = React.createRef();
 
   function toggleSuperChat() {
     if (superChatsChannelUrls && superChatsChannelUrls.length > 0) {
@@ -129,14 +136,14 @@ export default function LivestreamChatLayout(props: Props) {
       isMobile &&
       discussionElement &&
       viewMode === VIEW_MODES.CHAT &&
-      !didInitialScroll &&
+      (!didInitialScroll || bottomScrollTop === 0) &&
       discussionElement.scrollTop < discussionElement.scrollHeight
     ) {
       discussionElement.scrollTop = discussionElement.scrollHeight;
       setDidInitialScroll(true);
       setBottomScrollTop(discussionElement.scrollTop);
     }
-  }, [didInitialScroll, discussionElement, isMobile, viewMode]);
+  }, [bottomScrollTop, didInitialScroll, discussionElement, isMobile, viewMode]);
 
   // Register scroll handler (TODO: Should throttle/debounce)
   React.useEffect(() => {
@@ -334,10 +341,15 @@ export default function LivestreamChatLayout(props: Props) {
             <Spinner />
           </div>
         ) : (
-          <LivestreamComments uri={uri} commentsToDisplay={commentsToDisplay} isMobile={isMobile} />
+          <LivestreamComments
+            uri={uri}
+            commentsToDisplay={commentsToDisplay}
+            isMobile={isMobile}
+            restoreScrollPos={!hasRecentComments && !inputDrawerOpen && restoreScrollPos}
+          />
         )}
 
-        {scrollPos && (!isMobile || recentScrollPos) && scrollPos < recentScrollPos && viewMode === VIEW_MODES.CHAT ? (
+        {hasRecentComments ? (
           <Button
             button="secondary"
             className="livestream-comments__scroll-to-recent"
@@ -354,13 +366,10 @@ export default function LivestreamChatLayout(props: Props) {
             embed={embed}
             uri={uri}
             onDoneReplying={restoreScrollPos}
-            onSlimInputClick={
-              scrollPos &&
-              recentScrollPos &&
-              scrollPos >= recentScrollPos &&
-              viewMode === VIEW_MODES.CHAT &&
-              restoreScrollPos
-            }
+            onSlimInputClick={() => {
+              restoreScrollPos();
+              setInputDrawerOpen(!inputDrawerOpen);
+            }}
           />
         </div>
       </div>

ui/component/livestreamComment/view.jsx

@@ -28,10 +28,21 @@ type Props = {
   stakedLevel: number,
   isMobile?: boolean,
   handleDismissPin?: () => void,
+  restoreScrollPos?: () => void,
 };
 
 export default function LivestreamComment(props: Props) {
-  const { comment, forceUpdate, uri, claim, myChannelIds, stakedLevel, isMobile, handleDismissPin } = props;
+  const {
+    comment,
+    forceUpdate,
+    uri,
+    claim,
+    myChannelIds,
+    stakedLevel,
+    isMobile,
+    handleDismissPin,
+    restoreScrollPos,
+  } = props;
 
   const {
     channel_url: authorUri,
@@ -46,8 +57,6 @@ export default function LivestreamComment(props: Props) {
     timestamp,
   } = comment;
 
-  const commentRef = React.useRef();
-
   const [hasUserMention, setUserMention] = React.useState(false);
 
   const isStreamer = claim && claim.signing_channel && claim.signing_channel.permanent_url === authorUri;
@@ -56,10 +65,6 @@ export default function LivestreamComment(props: Props) {
   const isSticker = Boolean(stickerUrlFromMessage);
   const timePosted = timestamp * 1000;
   const commentIsMine = comment.channel_id && isMyComment(comment.channel_id);
-  const discussionElement = document.querySelector('.livestream__comments--mobile');
-  const currentComment = commentRef && commentRef.current;
-  const minScrollPos =
-    discussionElement && currentComment && discussionElement.scrollHeight - currentComment.offsetHeight;
 
   // todo: implement comment_list --mine in SDK so redux can grab with selectCommentIsMine
   function isMyComment(channelId: string) {
@@ -69,10 +74,10 @@ export default function LivestreamComment(props: Props) {
   // For every new <LivestreamComment /> component that is rendered on mobile view,
   // keep the scroll at the bottom (newest)
   React.useEffect(() => {
-    if (isMobile && discussionElement && minScrollPos && discussionElement.scrollTop >= minScrollPos) {
-      discussionElement.scrollTop = discussionElement.scrollHeight;
+    if (isMobile && restoreScrollPos) {
+      restoreScrollPos();
     }
-  }, [discussionElement, isMobile, minScrollPos]);
+  }, [isMobile, restoreScrollPos]);
 
   return (
     <li
@@ -82,7 +87,6 @@ export default function LivestreamComment(props: Props) {
         'livestream__comment--mentioned': hasUserMention,
         'livestream__comment--mobile': isMobile,
       })}
-      ref={commentRef}
     >
       {supportAmount > 0 && (
         <div className="livestreamComment__superchatBanner">

ui/component/livestreamComments/view.jsx

@@ -12,10 +12,11 @@ type Props = {
   fetchingComments: boolean,
   uri: string,
   isMobile?: boolean,
+  restoreScrollPos?: () => void,
 };
 
 export default function LivestreamComments(props: Props) {
-  const { commentsToDisplay, fetchingComments, uri, isMobile } = props;
+  const { commentsToDisplay, fetchingComments, uri, isMobile, restoreScrollPos } = props;
 
   const [forceUpdate, setForceUpdate] = React.useState(0);
 
@@ -56,6 +57,7 @@ export default function LivestreamComments(props: Props) {
               uri={uri}
               forceUpdate={forceUpdate}
               isMobile
+              restoreScrollPos={restoreScrollPos}
             />
           ))}
       </div>