Fix height cache (#4909)

app/javascript/mastodon/actions/height_cache.js

+export const HEIGHT_CACHE_SET = 'HEIGHT_CACHE_SET';
+export const HEIGHT_CACHE_CLEAR = 'HEIGHT_CACHE_CLEAR';
+
+export function setHeight (key, id, height) {
+  return {
+    type: HEIGHT_CACHE_SET,
+    key,
+    id,
+    height,
+  };
+};
+
+export function clearHeight () {
+  return {
+    type: HEIGHT_CACHE_CLEAR,
+  };
+};

app/javascript/mastodon/actions/statuses.js

@@ -23,9 +23,6 @@ export const STATUS_UNMUTE_REQUEST = 'STATUS_UNMUTE_REQUEST';
 export const STATUS_UNMUTE_SUCCESS = 'STATUS_UNMUTE_SUCCESS';
 export const STATUS_UNMUTE_FAIL    = 'STATUS_UNMUTE_FAIL';
 
-export const STATUS_SET_HEIGHT = 'STATUS_SET_HEIGHT';
-export const STATUSES_CLEAR_HEIGHT = 'STATUSES_CLEAR_HEIGHT';
-
 export function fetchStatusRequest(id, skipLoading) {
   return {
     type: STATUS_FETCH_REQUEST,
@@ -218,17 +215,3 @@ export function unmuteStatusFail(id, error) {
     error,
   };
 };
-
-export function setStatusHeight (id, height) {
-  return {
-    type: STATUS_SET_HEIGHT,
-    id,
-    height,
-  };
-};
-
-export function clearStatusesHeight () {
-  return {
-    type: STATUSES_CLEAR_HEIGHT,
-  };
-};

app/javascript/mastodon/components/intersection_observer_article.js

@@ -7,10 +7,13 @@ import getRectFromEntry from '../features/ui/util/get_rect_from_entry';
 export default class IntersectionObserverArticle extends ImmutablePureComponent {
 
   static propTypes = {
-    intersectionObserverWrapper: PropTypes.object,
+    intersectionObserverWrapper: PropTypes.object.isRequired,
     id: PropTypes.oneOfType([PropTypes.string, PropTypes.number]),
     index: PropTypes.oneOfType([PropTypes.string, PropTypes.number]),
     listLength: PropTypes.oneOfType([PropTypes.string, PropTypes.number]),
+    saveHeightKey: PropTypes.string,
+    cachedHeight: PropTypes.number,
+    onHeightChange: PropTypes.func,
     children: PropTypes.node,
   };
 
@@ -34,13 +37,10 @@ export default class IntersectionObserverArticle extends ImmutablePureComponent
   }
 
   componentDidMount () {
-    if (!this.props.intersectionObserverWrapper) {
-      // TODO: enable IntersectionObserver optimization for notification statuses.
-      // These are managed in notifications/index.js rather than status_list.js
-      return;
-    }
-    this.props.intersectionObserverWrapper.observe(
-      this.props.id,
+    const { intersectionObserverWrapper, id } = this.props;
+
+    intersectionObserverWrapper.observe(
+      id,
       this.node,
       this.handleIntersection
     );
@@ -49,20 +49,21 @@ export default class IntersectionObserverArticle extends ImmutablePureComponent
   }
 
   componentWillUnmount () {
-    if (this.props.intersectionObserverWrapper) {
-      this.props.intersectionObserverWrapper.unobserve(this.props.id, this.node);
-    }
+    const { intersectionObserverWrapper, id } = this.props;
+    intersectionObserverWrapper.unobserve(id, this.node);
 
     this.componentMounted = false;
   }
 
   handleIntersection = (entry) => {
+    const { onHeightChange, saveHeightKey, id } = this.props;
+
     if (this.node && this.node.children.length !== 0) {
       // save the height of the fully-rendered element
       this.height = getRectFromEntry(entry).height;
 
-      if (this.props.onHeightChange) {
-        this.props.onHeightChange(this.props.status, this.height);
+      if (onHeightChange && saveHeightKey) {
+        onHeightChange(saveHeightKey, id, this.height);
       }
     }
 
@@ -94,16 +95,16 @@ export default class IntersectionObserverArticle extends ImmutablePureComponent
   }
 
   render () {
-    const { children, id, index, listLength } = this.props;
+    const { children, id, index, listLength, cachedHeight } = this.props;
     const { isIntersecting, isHidden } = this.state;
 
-    if (!isIntersecting && isHidden) {
+    if (!isIntersecting && (isHidden || cachedHeight)) {
       return (
         <article
           ref={this.handleRef}
           aria-posinset={index}
           aria-setsize={listLength}
-          style={{ height: `${this.height}px`, opacity: 0, overflow: 'hidden' }}
+          style={{ height: `${this.height || cachedHeight}px`, opacity: 0, overflow: 'hidden' }}
           data-id={id}
           tabIndex='0'
         >

app/javascript/mastodon/components/scrollable_list.js

 import React, { PureComponent } from 'react';
 import { ScrollContainer } from 'react-router-scroll';
 import PropTypes from 'prop-types';
-import IntersectionObserverArticle from './intersection_observer_article';
+import IntersectionObserverArticleContainer from '../containers/intersection_observer_article_container';
 import LoadMore from './load_more';
 import IntersectionObserverWrapper from '../features/ui/util/intersection_observer_wrapper';
 import { throttle } from 'lodash';
@@ -9,6 +9,10 @@ import { List as ImmutableList } from 'immutable';
 
 export default class ScrollableList extends PureComponent {
 
+  static contextTypes = {
+    router: PropTypes.object,
+  };
+
   static propTypes = {
     scrollKey: PropTypes.string.isRequired,
     onScrollToBottom: PropTypes.func,
@@ -173,9 +177,16 @@ export default class ScrollableList extends PureComponent {
             {prepend}
 
             {React.Children.map(this.props.children, (child, index) => (
-              <IntersectionObserverArticle key={child.key} id={child.key} index={index} listLength={childrenCount} intersectionObserverWrapper={this.intersectionObserverWrapper}>
+              <IntersectionObserverArticleContainer
+                key={child.key}
+                id={child.key}
+                index={index}
+                listLength={childrenCount}
+                intersectionObserverWrapper={this.intersectionObserverWrapper}
+                saveHeightKey={trackScroll ? `${this.context.router.route.location.key}:${scrollKey}` : null}
+              >
                 {child}
-              </IntersectionObserverArticle>
+              </IntersectionObserverArticleContainer>
             ))}
 
             {loadMore}

app/javascript/mastodon/containers/intersection_observer_article_container.js

+import { connect } from 'react-redux';
+import IntersectionObserverArticle from '../components/intersection_observer_article';
+import { setHeight } from '../actions/height_cache';
+
+const makeMapStateToProps = (state, props) => ({
+  cachedHeight: state.getIn(['height_cache', props.saveHeightKey, props.id]),
+});
+
+const mapDispatchToProps = (dispatch) => ({
+
+  onHeightChange (key, id, height) {
+    dispatch(setHeight(key, id, height));
+  },
+
+});
+
+export default connect(makeMapStateToProps, mapDispatchToProps)(IntersectionObserverArticle);

app/javascript/mastodon/containers/status_container.js

@@ -18,7 +18,7 @@ import {
   blockAccount,
   muteAccount,
 } from '../actions/accounts';
-import { muteStatus, unmuteStatus, deleteStatus, setStatusHeight } from '../actions/statuses';
+import { muteStatus, unmuteStatus, deleteStatus } from '../actions/statuses';
 import { initReport } from '../actions/reports';
 import { openModal } from '../actions/modal';
 import { defineMessages, injectIntl, FormattedMessage } from 'react-intl';
@@ -138,10 +138,6 @@ const mapDispatchToProps = (dispatch, { intl }) => ({
     }
   },
 
-  onHeightChange (status, height) {
-    dispatch(setStatusHeight(status.get('id'), height));
-  },
-
 });
 
 export default injectIntl(connect(makeMapStateToProps, mapDispatchToProps)(Status));

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

@@ -11,7 +11,7 @@ import { debounce } from 'lodash';
 import { uploadCompose } from '../../actions/compose';
 import { refreshHomeTimeline } from '../../actions/timelines';
 import { refreshNotifications } from '../../actions/notifications';
-import { clearStatusesHeight } from '../../actions/statuses';
+import { clearHeight } from '../../actions/height_cache';
 import { WrappedSwitch, WrappedRoute } from './util/react_router_helpers';
 import UploadArea from './components/upload_area';
 import ColumnsAreaContainer from './containers/columns_area_container';
@@ -68,7 +68,7 @@ export default class UI extends React.PureComponent {
 
   handleResize = debounce(() => {
     // The cached heights are no longer accurate, invalidate
-    this.props.dispatch(clearStatusesHeight());
+    this.props.dispatch(clearHeight());
 
     this.setState({ width: window.innerWidth });
   }, 500, {

app/javascript/mastodon/reducers/height_cache.js

+import { Map as ImmutableMap } from 'immutable';
+import { HEIGHT_CACHE_SET, HEIGHT_CACHE_CLEAR } from '../actions/height_cache';
+
+const initialState = ImmutableMap();
+
+const setHeight = (state, key, id, height) => {
+  return state.update(key, ImmutableMap(), map => map.set(id, height));
+};
+
+const clearHeights = () => {
+  return ImmutableMap();
+};
+
+export default function statuses(state = initialState, action) {
+  switch(action.type) {
+  case HEIGHT_CACHE_SET:
+    return setHeight(state, action.key, action.id, action.height);
+  case HEIGHT_CACHE_CLEAR:
+    return clearHeights();
+  default:
+    return state;
+  }
+};

app/javascript/mastodon/reducers/index.js

@@ -19,6 +19,7 @@ import compose from './compose';
 import search from './search';
 import media_attachments from './media_attachments';
 import notifications from './notifications';
+import height_cache from './height_cache';
 
 const reducers = {
   timelines,
@@ -41,6 +42,7 @@ const reducers = {
   search,
   media_attachments,
   notifications,
+  height_cache,
 };
 
 export default combineReducers(reducers);

app/javascript/mastodon/reducers/statuses.js

@@ -15,8 +15,6 @@ import {
   CONTEXT_FETCH_SUCCESS,
   STATUS_MUTE_SUCCESS,
   STATUS_UNMUTE_SUCCESS,
-  STATUS_SET_HEIGHT,
-  STATUSES_CLEAR_HEIGHT,
 } from '../actions/statuses';
 import {
   TIMELINE_REFRESH_SUCCESS,
@@ -95,18 +93,6 @@ const filterStatuses = (state, relationship) => {
   return state;
 };
 
-const setHeight = (state, id, height) => {
-  return state.update(id, ImmutableMap(), map => map.set('height', height));
-};
-
-const clearHeights = (state) => {
-  state.forEach(status => {
-    state = state.deleteIn([status.get('id'), 'height']);
-  });
-
-  return state;
-};
-
 const initialState = ImmutableMap();
 
 export default function statuses(state = initialState, action) {
@@ -148,10 +134,6 @@ export default function statuses(state = initialState, action) {
     return deleteStatus(state, action.id, action.references);
   case ACCOUNT_BLOCK_SUCCESS:
     return filterStatuses(state, action.relationship);
-  case STATUS_SET_HEIGHT:
-    return setHeight(state, action.id, action.height);
-  case STATUSES_CLEAR_HEIGHT:
-    return clearHeights(state);
   default:
     return state;
   }