Use a context to propagate column-related Props, and remove forceUpdate usage (#27548)

app/javascript/mastodon/components/column_back_button.jsx

@@ -1,65 +0,0 @@
-import PropTypes from 'prop-types';
-import { PureComponent } from 'react';
-import { createPortal } from 'react-dom';
-
-import { FormattedMessage } from 'react-intl';
-
-import { withRouter } from 'react-router-dom';
-
-import { ReactComponent as ArrowBackIcon } from '@material-symbols/svg-600/outlined/arrow_back.svg';
-
-import { Icon }  from 'mastodon/components/icon';
-import { WithRouterPropTypes } from 'mastodon/utils/react_router';
-
-export class ColumnBackButton extends PureComponent {
-
-  static propTypes = {
-    multiColumn: PropTypes.bool,
-    onClick: PropTypes.func,
-    ...WithRouterPropTypes,
-  };
-
-  handleClick = () => {
-    const { onClick, history } = this.props;
-
-    if (onClick) {
-      onClick();
-    } else if (history.location?.state?.fromMastodon) {
-      history.goBack();
-    } else {
-      history.push('/');
-    }
-  };
-
-  render () {
-    const { multiColumn } = this.props;
-
-    const component = (
-      <button onClick={this.handleClick} className='column-back-button'>
-        <Icon id='chevron-left' icon={ArrowBackIcon} className='column-back-button__icon' />
-        <FormattedMessage id='column_back_button.label' defaultMessage='Back' />
-      </button>
-    );
-
-    if (multiColumn) {
-      return component;
-    } else {
-      // The portal container and the component may be rendered to the DOM in
-      // the same React render pass, so the container might not be available at
-      // the time `render()` is called.
-      const container = document.getElementById('tabs-bar__portal');
-      if (container === null) {
-        // The container wasn't available, force a re-render so that the
-        // component can eventually be inserted in the container and not scroll
-        // with the rest of the area.
-        this.forceUpdate();
-        return component;
-      } else {
-        return createPortal(component, container);
-      }
-    }
-  }
-
-}
-
-export default withRouter(ColumnBackButton);

app/javascript/mastodon/components/column_back_button.tsx

@@ -0,0 +1,70 @@
+import { useCallback } from 'react';
+
+import { FormattedMessage } from 'react-intl';
+
+import { ReactComponent as ArrowBackIcon } from '@material-symbols/svg-600/outlined/arrow_back.svg';
+
+import { Icon } from 'mastodon/components/icon';
+import { ButtonInTabsBar } from 'mastodon/features/ui/util/columns_context';
+
+import { useAppHistory } from './router';
+
+type OnClickCallback = () => void;
+
+function useHandleClick(onClick?: OnClickCallback) {
+  const history = useAppHistory();
+
+  return useCallback(() => {
+    if (onClick) {
+      onClick();
+    } else if (history.location.state?.fromMastodon) {
+      history.goBack();
+    } else {
+      history.push('/');
+    }
+  }, [history, onClick]);
+}
+
+export const ColumnBackButton: React.FC<{ onClick: OnClickCallback }> = ({
+  onClick,
+}) => {
+  const handleClick = useHandleClick(onClick);
+
+  const component = (
+    <button onClick={handleClick} className='column-back-button'>
+      <Icon
+        id='chevron-left'
+        icon={ArrowBackIcon}
+        className='column-back-button__icon'
+      />
+      <FormattedMessage id='column_back_button.label' defaultMessage='Back' />
+    </button>
+  );
+
+  return <ButtonInTabsBar>{component}</ButtonInTabsBar>;
+};
+
+export const ColumnBackButtonSlim: React.FC<{ onClick: OnClickCallback }> = ({
+  onClick,
+}) => {
+  const handleClick = useHandleClick(onClick);
+
+  return (
+    <div className='column-back-button--slim'>
+      {/* eslint-disable-next-line jsx-a11y/click-events-have-key-events */}
+      <div
+        role='button'
+        tabIndex={0}
+        onClick={handleClick}
+        className='column-back-button column-back-button--slim-button'
+      >
+        <Icon
+          id='chevron-left'
+          icon={ArrowBackIcon}
+          className='column-back-button__icon'
+        />
+        <FormattedMessage id='column_back_button.label' defaultMessage='Back' />
+      </div>
+    </div>
+  );
+};

app/javascript/mastodon/components/column_back_button_slim.jsx

@@ -1,20 +0,0 @@
-import { FormattedMessage } from 'react-intl';
-
-import { ReactComponent as ArrowBackIcon } from '@material-symbols/svg-600/outlined/arrow_back.svg';
-
-import { Icon }  from 'mastodon/components/icon';
-
-import { ColumnBackButton } from './column_back_button';
-
-export default class ColumnBackButtonSlim extends ColumnBackButton {
-  render () {
-    return (
-      <div className='column-back-button--slim'>
-        <div role='button' tabIndex={0} onClick={this.handleClick} className='column-back-button column-back-button--slim-button'>
-          <Icon id='chevron-left' icon={ArrowBackIcon} className='column-back-button__icon' />
-          <FormattedMessage id='column_back_button.label' defaultMessage='Back' />
-        </div>
-      </div>
-    );
-  }
-}

app/javascript/mastodon/components/column_header.jsx

@@ -1,6 +1,5 @@
 import PropTypes from 'prop-types';
 import { PureComponent } from 'react';
-import { createPortal } from 'react-dom';
 
 import { FormattedMessage, injectIntl, defineMessages } from 'react-intl';
 
@@ -15,6 +14,7 @@ import { ReactComponent as CloseIcon } from '@material-symbols/svg-600/outlined/
 import { ReactComponent as TuneIcon } from '@material-symbols/svg-600/outlined/tune.svg';
 
 import { Icon }  from 'mastodon/components/icon';
+import { ButtonInTabsBar } from 'mastodon/features/ui/util/columns_context';
 import { WithRouterPropTypes } from 'mastodon/utils/react_router';
 
 const messages = defineMessages({
@@ -203,22 +203,12 @@ class ColumnHeader extends PureComponent {
       </div>
     );
 
-    if (multiColumn || placeholder) {
+    if (placeholder) {
       return component;
     } else {
-      // The portal container and the component may be rendered to the DOM in
-      // the same React render pass, so the container might not be available at
-      // the time `render()` is called.
-      const container = document.getElementById('tabs-bar__portal');
-      if (container === null) {
-        // The container wasn't available, force a re-render so that the
-        // component can eventually be inserted in the container and not scroll
-        // with the rest of the area.
-        this.forceUpdate();
-        return component;
-      } else {
-        return createPortal(component, container);
-      }
+      return (<ButtonInTabsBar>
+        {component}
+      </ButtonInTabsBar>);
     }
   }
 

app/javascript/mastodon/components/router.tsx

@@ -1,7 +1,7 @@
 import type { PropsWithChildren } from 'react';
 import React from 'react';
 
-import { Router as OriginalRouter } from 'react-router';
+import { Router as OriginalRouter, useHistory } from 'react-router';
 
 import type {
   LocationDescriptor,
@@ -16,18 +16,23 @@ interface MastodonLocationState {
   fromMastodon?: boolean;
   mastodonModalKey?: string;
 }
-type HistoryPath = Path | LocationDescriptor<MastodonLocationState>;
 
-const browserHistory = createBrowserHistory<
-  MastodonLocationState | undefined
->();
+type LocationState = MastodonLocationState | null | undefined;
+
+type HistoryPath = Path | LocationDescriptor<LocationState>;
+
+const browserHistory = createBrowserHistory<LocationState>();
 const originalPush = browserHistory.push.bind(browserHistory);
 const originalReplace = browserHistory.replace.bind(browserHistory);
 
+export function useAppHistory() {
+  return useHistory<LocationState>();
+}
+
 function normalizePath(
   path: HistoryPath,
-  state?: MastodonLocationState,
-): LocationDescriptorObject<MastodonLocationState> {
+  state?: LocationState,
+): LocationDescriptorObject<LocationState> {
   const location = typeof path === 'string' ? { pathname: path } : { ...path };
 
   if (location.state === undefined && state !== undefined) {

app/javascript/mastodon/features/account_gallery/index.jsx

@@ -8,7 +8,7 @@ import { connect } from 'react-redux';
 
 import { lookupAccount, fetchAccount } from 'mastodon/actions/accounts';
 import { openModal } from 'mastodon/actions/modal';
-import ColumnBackButton from 'mastodon/components/column_back_button';
+import { ColumnBackButton } from 'mastodon/components/column_back_button';
 import { LoadMore } from 'mastodon/components/load_more';
 import { LoadingIndicator } from 'mastodon/components/loading_indicator';
 import ScrollContainer from 'mastodon/containers/scroll_container';
@@ -203,7 +203,7 @@ class AccountGallery extends ImmutablePureComponent {
 
     return (
       <Column>
-        <ColumnBackButton multiColumn={multiColumn} />
+        <ColumnBackButton />
 
         <ScrollContainer scrollKey='account_gallery'>
           <div className='scrollable scrollable--flex' onScroll={this.handleScroll}>

app/javascript/mastodon/features/account_timeline/index.jsx

@@ -16,7 +16,7 @@ import { getAccountHidden } from 'mastodon/selectors';
 import { lookupAccount, fetchAccount } from '../../actions/accounts';
 import { fetchFeaturedTags } from '../../actions/featured_tags';
 import { expandAccountFeaturedTimeline, expandAccountTimeline, connectTimeline, disconnectTimeline } from '../../actions/timelines';
-import ColumnBackButton from '../../components/column_back_button';
+import { ColumnBackButton } from '../../components/column_back_button';
 import { LoadingIndicator } from '../../components/loading_indicator';
 import StatusList from '../../components/status_list';
 import Column from '../ui/components/column';
@@ -184,7 +184,7 @@ class AccountTimeline extends ImmutablePureComponent {
 
     return (
       <Column>
-        <ColumnBackButton multiColumn={multiColumn} />
+        <ColumnBackButton />
 
         <StatusList
           prepend={<HeaderContainer accountId={this.props.accountId} hideTabs={forceEmptyState} tagged={this.props.params.tagged} />}

app/javascript/mastodon/features/blocks/index.jsx

@@ -10,7 +10,7 @@ import { ReactComponent as BlockIcon } from '@material-symbols/svg-600/outlined/
 import { debounce } from 'lodash';
 
 import { fetchBlocks, expandBlocks } from '../../actions/blocks';
-import ColumnBackButtonSlim from '../../components/column_back_button_slim';
+import { ColumnBackButtonSlim } from '../../components/column_back_button';
 import { LoadingIndicator } from '../../components/loading_indicator';
 import ScrollableList from '../../components/scrollable_list';
 import AccountContainer from '../../containers/account_container';

app/javascript/mastodon/features/domain_blocks/index.jsx

@@ -12,7 +12,7 @@ import { ReactComponent as BlockIcon } from '@material-symbols/svg-600/outlined/
 import { debounce } from 'lodash';
 
 import { fetchDomainBlocks, expandDomainBlocks } from '../../actions/domain_blocks';
-import ColumnBackButtonSlim from '../../components/column_back_button_slim';
+import { ColumnBackButtonSlim } from '../../components/column_back_button';
 import { LoadingIndicator } from '../../components/loading_indicator';
 import ScrollableList from '../../components/scrollable_list';
 import DomainContainer from '../../containers/domain_container';

app/javascript/mastodon/features/follow_requests/index.jsx

@@ -12,7 +12,7 @@ import { ReactComponent as PersonAddIcon } from '@material-symbols/svg-600/outli
 import { debounce } from 'lodash';
 
 import { fetchFollowRequests, expandFollowRequests } from '../../actions/accounts';
-import ColumnBackButtonSlim from '../../components/column_back_button_slim';
+import { ColumnBackButtonSlim } from '../../components/column_back_button';
 import ScrollableList from '../../components/scrollable_list';
 import { me } from '../../initial_state';
 import Column from '../ui/components/column';

app/javascript/mastodon/features/followers/index.jsx

@@ -19,7 +19,7 @@ import {
   fetchFollowers,
   expandFollowers,
 } from '../../actions/accounts';
-import ColumnBackButton from '../../components/column_back_button';
+import { ColumnBackButton } from '../../components/column_back_button';
 import { LoadingIndicator } from '../../components/loading_indicator';
 import ScrollableList from '../../components/scrollable_list';
 import AccountContainer from '../../containers/account_container';
@@ -147,7 +147,7 @@ class Followers extends ImmutablePureComponent {
 
     return (
       <Column>
-        <ColumnBackButton multiColumn={multiColumn} />
+        <ColumnBackButton />
 
         <ScrollableList
           scrollKey='followers'

app/javascript/mastodon/features/following/index.jsx

@@ -19,7 +19,7 @@ import {
   fetchFollowing,
   expandFollowing,
 } from '../../actions/accounts';
-import ColumnBackButton from '../../components/column_back_button';
+import { ColumnBackButton } from '../../components/column_back_button';
 import { LoadingIndicator } from '../../components/loading_indicator';
 import ScrollableList from '../../components/scrollable_list';
 import AccountContainer from '../../containers/account_container';
@@ -147,7 +147,7 @@ class Following extends ImmutablePureComponent {
 
     return (
       <Column>
-        <ColumnBackButton multiColumn={multiColumn} />
+        <ColumnBackButton />
 
         <ScrollableList
           scrollKey='following'

app/javascript/mastodon/features/mutes/index.jsx

@@ -12,7 +12,7 @@ import { ReactComponent as VolumeOffIcon } from '@material-symbols/svg-600/outli
 import { debounce } from 'lodash';
 
 import { fetchMutes, expandMutes } from '../../actions/mutes';
-import ColumnBackButtonSlim from '../../components/column_back_button_slim';
+import { ColumnBackButtonSlim } from '../../components/column_back_button';
 import { LoadingIndicator } from '../../components/loading_indicator';
 import ScrollableList from '../../components/scrollable_list';
 import AccountContainer from '../../containers/account_container';

app/javascript/mastodon/features/onboarding/follows.jsx

@@ -9,7 +9,7 @@ import { connect } from 'react-redux';
 import { fetchSuggestions } from 'mastodon/actions/suggestions';
 import { markAsPartial } from 'mastodon/actions/timelines';
 import Column from 'mastodon/components/column';
-import ColumnBackButton from 'mastodon/components/column_back_button';
+import { ColumnBackButton } from 'mastodon/components/column_back_button';
 import { EmptyAccount } from 'mastodon/components/empty_account';
 import Account from 'mastodon/containers/account_container';
 
@@ -25,7 +25,6 @@ class Follows extends PureComponent {
     dispatch: PropTypes.func.isRequired,
     suggestions: ImmutablePropTypes.list,
     isLoading: PropTypes.bool,
-    multiColumn: PropTypes.bool,
   };
 
   componentDidMount () {
@@ -39,7 +38,7 @@ class Follows extends PureComponent {
   }
 
   render () {
-    const { onBack, isLoading, suggestions, multiColumn } = this.props;
+    const { onBack, isLoading, suggestions } = this.props;
 
     let loadedContent;
 
@@ -53,7 +52,7 @@ class Follows extends PureComponent {
 
     return (
       <Column>
-        <ColumnBackButton multiColumn={multiColumn} onClick={onBack} />
+        <ColumnBackButton onClick={onBack} />
 
         <div className='scrollable privacy-policy'>
           <div className='column-title'>

app/javascript/mastodon/features/onboarding/index.jsx

@@ -47,7 +47,6 @@ class Onboarding extends ImmutablePureComponent {
   static propTypes = {
     dispatch: PropTypes.func.isRequired,
     account: ImmutablePropTypes.map,
-    multiColumn: PropTypes.bool,
     ...WithRouterPropTypes,
   };
 
@@ -100,14 +99,14 @@ class Onboarding extends ImmutablePureComponent {
   }
 
   render () {
-    const { account, multiColumn } = this.props;
+    const { account } = this.props;
     const { step, shareClicked } = this.state;
 
     switch(step) {
     case 'follows':
-      return <Follows onBack={this.handleBackClick} multiColumn={multiColumn} />;
+      return <Follows onBack={this.handleBackClick} />;
     case 'share':
-      return <Share onBack={this.handleBackClick} multiColumn={multiColumn} />;
+      return <Share onBack={this.handleBackClick} />;
     }
 
     return (

app/javascript/mastodon/features/onboarding/share.jsx

@@ -14,7 +14,7 @@ import { ReactComponent as ContentCopyIcon } from '@material-symbols/svg-600/out
 import SwipeableViews from 'react-swipeable-views';
 
 import Column from 'mastodon/components/column';
-import ColumnBackButton from 'mastodon/components/column_back_button';
+import { ColumnBackButton } from 'mastodon/components/column_back_button';
 import { Icon }  from 'mastodon/components/icon';
 import { me, domain } from 'mastodon/initial_state';
 
@@ -146,18 +146,17 @@ class Share extends PureComponent {
   static propTypes = {
     onBack: PropTypes.func,
     account: ImmutablePropTypes.map,
-    multiColumn: PropTypes.bool,
     intl: PropTypes.object,
   };
 
   render () {
-    const { onBack, account, multiColumn, intl } = this.props;
+    const { onBack, account, intl } = this.props;
 
     const url = (new URL(`/@${account.get('username')}`, document.baseURI)).href;
 
     return (
       <Column>
-        <ColumnBackButton multiColumn={multiColumn} onClick={onBack} />
+        <ColumnBackButton onClick={onBack} />
 
         <div className='scrollable privacy-policy'>
           <div className='column-title'>

app/javascript/mastodon/features/pinned_statuses/index.jsx

@@ -13,7 +13,7 @@ import { ReactComponent as PushPinIcon } from '@material-symbols/svg-600/outline
 import { getStatusList } from 'mastodon/selectors';
 
 import { fetchPinnedStatuses } from '../../actions/pin_statuses';
-import ColumnBackButtonSlim from '../../components/column_back_button_slim';
+import { ColumnBackButtonSlim } from '../../components/column_back_button';
 import StatusList from '../../components/status_list';
 import Column from '../ui/components/column';
 

app/javascript/mastodon/features/ui/components/columns_area.jsx

@@ -1,5 +1,5 @@
 import PropTypes from 'prop-types';
-import { Children, cloneElement } from 'react';
+import { Children, cloneElement, useCallback } from 'react';
 
 import ImmutablePropTypes from 'react-immutable-proptypes';
 import ImmutablePureComponent from 'react-immutable-pure-component';
@@ -21,6 +21,7 @@ import {
   ListTimeline,
   Directory,
 } from '../util/async-components';
+import { useColumnsContext } from '../util/columns_context';
 
 import BundleColumnError from './bundle_column_error';
 import { ColumnLoading } from './column_loading';
@@ -43,6 +44,17 @@ const componentMap = {
   'DIRECTORY': Directory,
 };
 
+const TabsBarPortal = () => {
+  const {setTabsBarElement} = useColumnsContext();
+
+  const setRef = useCallback((element) => {
+    if(element)
+      setTabsBarElement(element);
+  }, [setTabsBarElement]);
+
+  return <div id='tabs-bar__portal' ref={setRef} />;
+};
+
 export default class ColumnsArea extends ImmutablePureComponent {
   static propTypes = {
     columns: ImmutablePropTypes.list.isRequired,
@@ -146,7 +158,7 @@ export default class ColumnsArea extends ImmutablePureComponent {
           </div>
 
           <div className='columns-area__panels__main'>
-            <div className='tabs-bar__wrapper'><div id='tabs-bar__portal' /></div>
+            <div className='tabs-bar__wrapper'><TabsBarPortal /></div>
             <div className='columns-area columns-area--mobile'>{children}</div>
           </div>
 

app/javascript/mastodon/features/ui/index.jsx

@@ -64,8 +64,8 @@ import {
   About,
   PrivacyPolicy,
 } from './util/async-components';
+import { ColumnsContextProvider } from './util/columns_context';
 import { WrappedSwitch, WrappedRoute } from './util/react_router_helpers';
-
 // Dummy import, to make sure that <Status /> ends up in the application bundle.
 // Without this it ends up in ~8 very commonly used bundles.
 import '../../components/status';
@@ -179,68 +179,70 @@ class SwitchingColumnsArea extends PureComponent {
     }
 
     return (
-      <ColumnsAreaContainer ref={this.setRef} singleColumn={singleColumn}>
-        <WrappedSwitch>
-          {redirect}
+      <ColumnsContextProvider multiColumn={!singleColumn}>
+        <ColumnsAreaContainer ref={this.setRef} singleColumn={singleColumn}>
+          <WrappedSwitch>
+            {redirect}
 
-          {singleColumn ? <Redirect from='/deck' to='/home' exact /> : null}
-          {singleColumn && pathName.startsWith('/deck/') ? <Redirect from={pathName} to={pathName.slice(5)} /> : null}
-          {/* Redirect old bookmarks (without /deck) with home-like routes to the advanced interface */}
-          {!singleColumn && pathName === '/getting-started' ? <Redirect from='/getting-started' to='/deck/getting-started' exact /> : null}
-          {!singleColumn && pathName === '/home' ? <Redirect from='/home' to='/deck/getting-started' exact /> : null}
+            {singleColumn ? <Redirect from='/deck' to='/home' exact /> : null}
+            {singleColumn && pathName.startsWith('/deck/') ? <Redirect from={pathName} to={pathName.slice(5)} /> : null}
+            {/* Redirect old bookmarks (without /deck) with home-like routes to the advanced interface */}
+            {!singleColumn && pathName === '/getting-started' ? <Redirect from='/getting-started' to='/deck/getting-started' exact /> : null}
+            {!singleColumn && pathName === '/home' ? <Redirect from='/home' to='/deck/getting-started' exact /> : null}
 
-          <WrappedRoute path='/getting-started' component={GettingStarted} content={children} />
-          <WrappedRoute path='/keyboard-shortcuts' component={KeyboardShortcuts} content={children} />
-          <WrappedRoute path='/about' component={About} content={children} />
-          <WrappedRoute path='/privacy-policy' component={PrivacyPolicy} content={children} />
+            <WrappedRoute path='/getting-started' component={GettingStarted} content={children} />
+            <WrappedRoute path='/keyboard-shortcuts' component={KeyboardShortcuts} content={children} />
+            <WrappedRoute path='/about' component={About} content={children} />
+            <WrappedRoute path='/privacy-policy' component={PrivacyPolicy} content={children} />
 
-          <WrappedRoute path={['/home', '/timelines/home']} component={HomeTimeline} content={children} />
-          <Redirect from='/timelines/public' to='/public' exact />
-          <Redirect from='/timelines/public/local' to='/public/local' exact />
-          <WrappedRoute path='/public' exact component={Firehose} componentParams={{ feedType: 'public' }} content={children} />
-          <WrappedRoute path='/public/local' exact component={Firehose} componentParams={{ feedType: 'community' }} content={children} />
-          <WrappedRoute path='/public/remote' exact component={Firehose} componentParams={{ feedType: 'public:remote' }} content={children} />
-          <WrappedRoute path={['/conversations', '/timelines/direct']} component={DirectTimeline} content={children} />
-          <WrappedRoute path='/tags/:id' component={HashtagTimeline} content={children} />
-          <WrappedRoute path='/lists/:id' component={ListTimeline} content={children} />
-          <WrappedRoute path='/notifications' component={Notifications} content={children} />
-          <WrappedRoute path='/favourites' component={FavouritedStatuses} content={children} />
+            <WrappedRoute path={['/home', '/timelines/home']} component={HomeTimeline} content={children} />
+            <Redirect from='/timelines/public' to='/public' exact />
+            <Redirect from='/timelines/public/local' to='/public/local' exact />
+            <WrappedRoute path='/public' exact component={Firehose} componentParams={{ feedType: 'public' }} content={children} />
+            <WrappedRoute path='/public/local' exact component={Firehose} componentParams={{ feedType: 'community' }} content={children} />
+            <WrappedRoute path='/public/remote' exact component={Firehose} componentParams={{ feedType: 'public:remote' }} content={children} />
+            <WrappedRoute path={['/conversations', '/timelines/direct']} component={DirectTimeline} content={children} />
+            <WrappedRoute path='/tags/:id' component={HashtagTimeline} content={children} />
+            <WrappedRoute path='/lists/:id' component={ListTimeline} content={children} />
+            <WrappedRoute path='/notifications' component={Notifications} content={children} />
+            <WrappedRoute path='/favourites' component={FavouritedStatuses} content={children} />
 
-          <WrappedRoute path='/bookmarks' component={BookmarkedStatuses} content={children} />
-          <WrappedRoute path='/pinned' component={PinnedStatuses} content={children} />
+            <WrappedRoute path='/bookmarks' component={BookmarkedStatuses} content={children} />
+            <WrappedRoute path='/pinned' component={PinnedStatuses} content={children} />
 
-          <WrappedRoute path='/start' exact component={Onboarding} content={children} />
-          <WrappedRoute path='/directory' component={Directory} content={children} />
-          <WrappedRoute path={['/explore', '/search']} component={Explore} content={children} />
-          <WrappedRoute path={['/publish', '/statuses/new']} component={Compose} content={children} />
+            <WrappedRoute path='/start' exact component={Onboarding} content={children} />
+            <WrappedRoute path='/directory' component={Directory} content={children} />
+            <WrappedRoute path={['/explore', '/search']} component={Explore} content={children} />
+            <WrappedRoute path={['/publish', '/statuses/new']} component={Compose} content={children} />
 
-          <WrappedRoute path={['/@:acct', '/accounts/:id']} exact component={AccountTimeline} content={children} />
-          <WrappedRoute path='/@:acct/tagged/:tagged?' exact component={AccountTimeline} content={children} />
-          <WrappedRoute path={['/@:acct/with_replies', '/accounts/:id/with_replies']} component={AccountTimeline} content={children} componentParams={{ withReplies: true }} />
-          <WrappedRoute path={['/accounts/:id/followers', '/users/:acct/followers', '/@:acct/followers']} component={Followers} content={children} />
-          <WrappedRoute path={['/accounts/:id/following', '/users/:acct/following', '/@:acct/following']} component={Following} content={children} />
-          <WrappedRoute path={['/@:acct/media', '/accounts/:id/media']} component={AccountGallery} content={children} />
-          <WrappedRoute path='/@:acct/:statusId' exact component={Status} content={children} />
-          <WrappedRoute path='/@:acct/:statusId/reblogs' component={Reblogs} content={children} />
-          <WrappedRoute path='/@:acct/:statusId/favourites' component={Favourites} content={children} />
+            <WrappedRoute path={['/@:acct', '/accounts/:id']} exact component={AccountTimeline} content={children} />
+            <WrappedRoute path='/@:acct/tagged/:tagged?' exact component={AccountTimeline} content={children} />
+            <WrappedRoute path={['/@:acct/with_replies', '/accounts/:id/with_replies']} component={AccountTimeline} content={children} componentParams={{ withReplies: true }} />
+            <WrappedRoute path={['/accounts/:id/followers', '/users/:acct/followers', '/@:acct/followers']} component={Followers} content={children} />
+            <WrappedRoute path={['/accounts/:id/following', '/users/:acct/following', '/@:acct/following']} component={Following} content={children} />
+            <WrappedRoute path={['/@:acct/media', '/accounts/:id/media']} component={AccountGallery} content={children} />
+            <WrappedRoute path='/@:acct/:statusId' exact component={Status} content={children} />
+            <WrappedRoute path='/@:acct/:statusId/reblogs' component={Reblogs} content={children} />
+            <WrappedRoute path='/@:acct/:statusId/favourites' component={Favourites} content={children} />
 
-          {/* Legacy routes, cannot be easily factored with other routes because they share a param name */}
-          <WrappedRoute path='/timelines/tag/:id' component={HashtagTimeline} content={children} />
-          <WrappedRoute path='/timelines/list/:id' component={ListTimeline} content={children} />
-          <WrappedRoute path='/statuses/:statusId' exact component={Status} content={children} />
-          <WrappedRoute path='/statuses/:statusId/reblogs' component={Reblogs} content={children} />
-          <WrappedRoute path='/statuses/:statusId/favourites' component={Favourites} content={children} />
+            {/* Legacy routes, cannot be easily factored with other routes because they share a param name */}
+            <WrappedRoute path='/timelines/tag/:id' component={HashtagTimeline} content={children} />
+            <WrappedRoute path='/timelines/list/:id' component={ListTimeline} content={children} />
+            <WrappedRoute path='/statuses/:statusId' exact component={Status} content={children} />
+            <WrappedRoute path='/statuses/:statusId/reblogs' component={Reblogs} content={children} />
+            <WrappedRoute path='/statuses/:statusId/favourites' component={Favourites} content={children} />
 
-          <WrappedRoute path='/follow_requests' component={FollowRequests} content={children} />
-          <WrappedRoute path='/blocks' component={Blocks} content={children} />
-          <WrappedRoute path='/domain_blocks' component={DomainBlocks} content={children} />
-          <WrappedRoute path='/followed_tags' component={FollowedTags} content={children} />
-          <WrappedRoute path='/mutes' component={Mutes} content={children} />
-          <WrappedRoute path='/lists' component={Lists} content={children} />
+            <WrappedRoute path='/follow_requests' component={FollowRequests} content={children} />
+            <WrappedRoute path='/blocks' component={Blocks} content={children} />
+            <WrappedRoute path='/domain_blocks' component={DomainBlocks} content={children} />
+            <WrappedRoute path='/followed_tags' component={FollowedTags} content={children} />
+            <WrappedRoute path='/mutes' component={Mutes} content={children} />
+            <WrappedRoute path='/lists' component={Lists} content={children} />
 
-          <Route component={BundleColumnError} />
-        </WrappedSwitch>
-      </ColumnsAreaContainer>
+            <Route component={BundleColumnError} />
+          </WrappedSwitch>
+        </ColumnsAreaContainer>
+      </ColumnsContextProvider>
     );
   }
 

app/javascript/mastodon/features/ui/util/columns_context.tsx

@@ -0,0 +1,51 @@
+import type { ReactElement } from 'react';
+import { createContext, useContext, useMemo, useState } from 'react';
+import { createPortal } from 'react-dom';
+
+export const ColumnsContext = createContext<{
+  tabsBarElement: HTMLElement | null;
+  setTabsBarElement: (element: HTMLElement) => void;
+  multiColumn: boolean;
+}>({
+  tabsBarElement: null,
+  multiColumn: false,
+  setTabsBarElement: () => undefined, // no-op
+});
+
+export function useColumnsContext() {
+  return useContext(ColumnsContext);
+}
+
+export const ButtonInTabsBar: React.FC<{
+  children: ReactElement | string | undefined;
+}> = ({ children }) => {
+  const { multiColumn, tabsBarElement } = useColumnsContext();
+
+  if (multiColumn) {
+    return children;
+  } else if (!tabsBarElement) {
+    return children;
+  } else {
+    return createPortal(children, tabsBarElement);
+  }
+};
+
+type ContextValue = React.ContextType<typeof ColumnsContext>;
+
+export const ColumnsContextProvider: React.FC<
+  React.PropsWithChildren<{ multiColumn: boolean }>
+> = ({ multiColumn, children }) => {
+  const [tabsBarElement, setTabsBarElement] =
+    useState<ContextValue['tabsBarElement']>(null);
+
+  const contextValue = useMemo<ContextValue>(
+    () => ({ multiColumn, tabsBarElement, setTabsBarElement }),
+    [multiColumn, tabsBarElement],
+  );
+
+  return (
+    <ColumnsContext.Provider value={contextValue}>
+      {children}
+    </ColumnsContext.Provider>
+  );
+};