Do not scroll the columns area due to redirection (#4541)

Commit 9d1f8b9d6af1d384a4dd68bc6353a2fde5735b33 scrolls the columns area
when the route changes since the user is likely to want to see the
rightmost column in such cases.

However, redirection is automatic and does not indicate users' intension.
Do not scroll the columns area due to one.

3 files changed, 20 insertions, 8 deletions

diff --git a/app/javascript/mastodon/features/ui/components/columns_area.js b/app/javascript/mastodon/features/ui/components/columns_area.js
index 47d5a2e20..de3a199c7 100644
--- a/app/javascript/mastodon/features/ui/components/columns_area.js
+++ b/app/javascript/mastodon/features/ui/components/columns_area.js
@@ -24,7 +24,7 @@ const componentMap = {
   'FAVOURITES': FavouritedStatuses,
 };
 
-@injectIntl
+@component => injectIntl(component, { withRef: true })
 export default class ColumnsArea extends ImmutablePureComponent {
 
   static contextTypes = {
@@ -51,13 +51,13 @@ export default class ColumnsArea extends ImmutablePureComponent {
     this.setState({ shouldAnimate: true });
   }
 
-  componentDidUpdate(prevProps) {
+  componentDidUpdate() {
     this.lastIndex = getIndex(this.context.router.history.location.pathname);
     this.setState({ shouldAnimate: true });
+  }
 
-    if (this.props.children !== prevProps.children && !this.props.singleColumn) {
-      scrollRight(this.node);
-    }
+  handleChildrenContentChange() {
+    scrollRight(this.node);
   }
 
   handleSwipe = (index) => {
diff --git a/app/javascript/mastodon/features/ui/containers/columns_area_container.js b/app/javascript/mastodon/features/ui/containers/columns_area_container.js
index 6420f0784..95f95618b 100644
--- a/app/javascript/mastodon/features/ui/containers/columns_area_container.js
+++ b/app/javascript/mastodon/features/ui/containers/columns_area_container.js
@@ -5,4 +5,4 @@ const mapStateToProps = state => ({
   columns: state.getIn(['settings', 'columns']),
 });
 
-export default connect(mapStateToProps)(ColumnsArea);
+export default connect(mapStateToProps, null, null, { withRef: true })(ColumnsArea);
diff --git a/app/javascript/mastodon/features/ui/index.js b/app/javascript/mastodon/features/ui/index.js
index 44243d370..34b59fcc5 100644
--- a/app/javascript/mastodon/features/ui/index.js
+++ b/app/javascript/mastodon/features/ui/index.js
@@ -1,12 +1,12 @@
 import React from 'react';
 import classNames from 'classnames';
-import Redirect from 'react-router-dom/Redirect';
 import NotificationsContainer from './containers/notifications_container';
 import PropTypes from 'prop-types';
 import LoadingBarContainer from './containers/loading_bar_container';
 import TabsBar from './components/tabs_bar';
 import ModalContainer from './containers/modal_container';
 import { connect } from 'react-redux';
+import { Redirect, withRouter } from 'react-router-dom';
 import { isMobile } from '../../is_mobile';
 import { debounce } from 'lodash';
 import { uploadCompose } from '../../actions/compose';
@@ -48,6 +48,7 @@ const mapStateToProps = state => ({
 });
 
 @connect(mapStateToProps)
+@withRouter
 export default class UI extends React.PureComponent {
 
   static contextTypes = {
@@ -59,6 +60,7 @@ export default class UI extends React.PureComponent {
     children: PropTypes.node,
     systemFontUi: PropTypes.bool,
     isComposing: PropTypes.bool,
+    location: PropTypes.object,
   };
 
   state = {
@@ -168,6 +170,12 @@ export default class UI extends React.PureComponent {
     return true;
   }
 
+  componentDidUpdate (prevProps) {
+    if (![this.props.location.pathname, '/'].includes(prevProps.location.pathname)) {
+      this.columnsAreaNode.handleChildrenContentChange();
+    }
+  }
+
   componentWillUnmount () {
     window.removeEventListener('resize', this.handleResize);
     document.removeEventListener('dragenter', this.handleDragEnter);
@@ -181,6 +189,10 @@ export default class UI extends React.PureComponent {
     this.node = c;
   }
 
+  setColumnsAreaRef = (c) => {
+    this.columnsAreaNode = c.getWrappedInstance().getWrappedInstance();
+  }
+
   render () {
     const { width, draggingOver } = this.state;
     const { children } = this.props;
@@ -192,7 +204,7 @@ export default class UI extends React.PureComponent {
     return (
       <div className={className} ref={this.setRef}>
         <TabsBar />
-        <ColumnsAreaContainer singleColumn={isMobile(width)}>
+        <ColumnsAreaContainer ref={this.setColumnsAreaRef} singleColumn={isMobile(width)}>
           <WrappedSwitch>
             <Redirect from='/' to='/getting-started' exact />
             <WrappedRoute path='/getting-started' component={GettingStarted} content={children} />