Merge branch 'fix-tl-jump' into 'main'

Fix home timeline jump when navigating back

See merge request soapbox-pub/soapbox!2772

src/components/scroll-top-button.tsx

@@ -1,10 +1,8 @@
-import clsx from 'clsx';
 import throttle from 'lodash/throttle';
 import React, { useState, useEffect, useCallback } from 'react';
 import { useIntl, MessageDescriptor } from 'react-intl';
 
-import Icon from 'soapbox/components/icon';
-import { Text } from 'soapbox/components/ui';
+import { Icon, Text } from 'soapbox/components/ui';
 import { useSettings } from 'soapbox/hooks';
 
 interface IScrollTopButton {
@@ -31,67 +29,77 @@ const ScrollTopButton: React.FC<IScrollTopButton> = ({
   const intl = useIntl();
   const settings = useSettings();
 
+  // Whether we are scrolled past the `threshold`.
   const [scrolled, setScrolled] = useState<boolean>(false);
-  const autoload = settings.get('autoloadTimelines') === true;
+  // Whether we are scrolled above the `autoloadThreshold`.
+  const [scrolledTop, setScrolledTop] = useState<boolean>(false);
 
+  const autoload = settings.get('autoloadTimelines') === true;
   const visible = count > 0 && scrolled;
 
-  const classes = clsx('fixed left-1/2 top-20 z-50 -translate-x-1/2', {
-    'hidden': !visible,
-  });
-
+  /** Number of pixels scrolled down from the top of the page. */
   const getScrollTop = (): number => {
     return (document.scrollingElement || document.documentElement).scrollTop;
   };
 
-  const maybeUnload = () => {
-    if (autoload && getScrollTop() <= autoloadThreshold) {
+  /** Unload feed items if scrolled to the top. */
+  const maybeUnload = useCallback(() => {
+    if (autoload && scrolledTop) {
       onClick();
     }
-  };
+  }, [autoload, scrolledTop, onClick]);
 
+  /** Set state while scrolling. */
   const handleScroll = useCallback(throttle(() => {
-    maybeUnload();
+    const scrollTop = getScrollTop();
 
-    if (getScrollTop() > threshold) {
-      setScrolled(true);
-    } else {
-      setScrolled(false);
-    }
-  }, 150, { trailing: true }), [autoload, threshold, autoloadThreshold, onClick]);
+    setScrolled(scrollTop > threshold);
+    setScrolledTop(scrollTop <= autoloadThreshold);
 
-  const scrollUp = () => {
+  }, 150, { trailing: true }), [threshold, autoloadThreshold]);
+
+  /** Scroll to top and trigger `onClick`. */
+  const handleClick: React.MouseEventHandler = useCallback(() => {
     window.scrollTo({ top: 0 });
-  };
-
-  const handleClick: React.MouseEventHandler = () => {
-    setTimeout(scrollUp, 10);
     onClick();
-  };
+  }, [onClick]);
 
   useEffect(() => {
-    window.addEventListener('scroll', handleScroll);
+    // Delay adding the scroll listener so navigating back doesn't
+    // unload feed items before the feed is rendered.
+    setTimeout(() => {
+      window.addEventListener('scroll', handleScroll);
+      handleScroll();
+    }, 250);
 
     return () => {
       window.removeEventListener('scroll', handleScroll);
     };
-  }, [onClick]);
+  }, [handleScroll]);
 
   useEffect(() => {
     maybeUnload();
-  }, [count]);
+  }, [maybeUnload]);
+
+  if (!visible) {
+    return null;
+  }
 
   return (
-    <div className={classes}>
-      <a className='flex cursor-pointer items-center space-x-1.5 whitespace-nowrap rounded-full bg-primary-600 px-4 py-2 text-white transition-transform hover:scale-105 hover:bg-primary-700 active:scale-100' onClick={handleClick}>
-        <Icon src={require('@tabler/icons/arrow-bar-to-up.svg')} />
+    <div className='fixed left-1/2 top-20 z-50 -translate-x-1/2'>
+      <button
+        className='flex cursor-pointer items-center space-x-1.5 whitespace-nowrap rounded-full bg-primary-600 px-4 py-2 text-white transition-transform hover:scale-105 hover:bg-primary-700 active:scale-100'
+        onClick={handleClick}
+      >
+        <Icon
+          className='h-4 w-4'
+          src={require('@tabler/icons/arrow-bar-to-up.svg')}
+        />
 
-        {(count > 0) && (
-          <Text theme='inherit' size='sm'>
-            {intl.formatMessage(message, { count })}
-          </Text>
-        )}
-      </a>
+        <Text theme='inherit' size='sm'>
+          {intl.formatMessage(message, { count })}
+        </Text>
+      </button>
     </div>
   );
 };

src/features/notifications/index.tsx

@@ -14,7 +14,7 @@ import { getSettings } from 'soapbox/actions/settings';
 import PullToRefresh from 'soapbox/components/pull-to-refresh';
 import ScrollTopButton from 'soapbox/components/scroll-top-button';
 import ScrollableList from 'soapbox/components/scrollable-list';
-import { Column } from 'soapbox/components/ui';
+import { Column, Portal } from 'soapbox/components/ui';
 import PlaceholderNotification from 'soapbox/features/placeholder/components/placeholder-notification';
 import { useAppDispatch, useAppSelector, useSettings } from 'soapbox/hooks';
 
@@ -104,13 +104,13 @@ const Notifications = () => {
     });
   };
 
-  const handleDequeueNotifications = () => {
+  const handleDequeueNotifications = useCallback(() => {
     dispatch(dequeueNotifications());
-  };
+  }, []);
 
-  const handleRefresh = () => {
+  const handleRefresh = useCallback(() => {
     return dispatch(expandNotifications());
-  };
+  }, []);
 
   useEffect(() => {
     handleDequeueNotifications();
@@ -176,11 +176,15 @@ const Notifications = () => {
   return (
     <Column ref={column} label={intl.formatMessage(messages.title)} withHeader={false}>
       {filterBarContainer}
-      <ScrollTopButton
-        onClick={handleDequeueNotifications}
-        count={totalQueuedNotificationsCount}
-        message={messages.queue}
-      />
+
+      <Portal>
+        <ScrollTopButton
+          onClick={handleDequeueNotifications}
+          count={totalQueuedNotificationsCount}
+          message={messages.queue}
+        />
+      </Portal>
+
       <PullToRefresh onRefresh={handleRefresh}>
         {scrollContainer}
       </PullToRefresh>

src/features/ui/components/timeline.tsx

@@ -6,6 +6,7 @@ import { defineMessages } from 'react-intl';
 import { dequeueTimeline, scrollTopTimeline } from 'soapbox/actions/timelines';
 import ScrollTopButton from 'soapbox/components/scroll-top-button';
 import StatusList, { IStatusList } from 'soapbox/components/status-list';
+import { Portal } from 'soapbox/components/ui';
 import { useAppSelector, useAppDispatch } from 'soapbox/hooks';
 import { makeGetStatusIds } from 'soapbox/selectors';
 
@@ -37,9 +38,9 @@ const Timeline: React.FC<ITimeline> = ({
   const hasMore = useAppSelector(state => state.timelines.get(timelineId)?.hasMore === true);
   const totalQueuedItemsCount = useAppSelector(state => state.timelines.get(timelineId)?.totalQueuedItemsCount || 0);
 
-  const handleDequeueTimeline = () => {
+  const handleDequeueTimeline = useCallback(() => {
     dispatch(dequeueTimeline(timelineId, onLoadMore));
-  };
+  }, []);
 
   const handleScrollToTop = useCallback(debounce(() => {
     dispatch(scrollTopTimeline(timelineId, true));
@@ -51,12 +52,14 @@ const Timeline: React.FC<ITimeline> = ({
 
   return (
     <>
-      <ScrollTopButton
-        key='timeline-queue-button-header'
-        onClick={handleDequeueTimeline}
-        count={totalQueuedItemsCount}
-        message={messages.queue}
-      />
+      <Portal>
+        <ScrollTopButton
+          key='timeline-queue-button-header'
+          onClick={handleDequeueTimeline}
+          count={totalQueuedItemsCount}
+          message={messages.queue}
+        />
+      </Portal>
 
       <StatusList
         timelineId={timelineId}