DELETE INTERSECTION OBSERVER ARTICLE

app/soapbox/actions/height_cache.js

@@ -1,17 +0,0 @@
-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/soapbox/components/intersection_observer_article.js

@@ -1,131 +0,0 @@
-import { is } from 'immutable';
-import PropTypes from 'prop-types';
-import React from 'react';
-
-import getRectFromEntry from '../features/ui/util/get_rect_from_entry';
-import scheduleIdleTask from '../features/ui/util/schedule_idle_task';
-
-// Diff these props in the "rendered" state
-const updateOnPropsForRendered = ['id', 'index', 'listLength'];
-// Diff these props in the "unrendered" state
-const updateOnPropsForUnrendered = ['id', 'index', 'listLength', 'cachedHeight'];
-
-export default class IntersectionObserverArticle extends React.Component {
-
-  static propTypes = {
-    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,
-  };
-
-  state = {
-    isHidden: false, // set to true in requestIdleCallback to trigger un-render
-    isIntersecting: true,
-  }
-
-  shouldComponentUpdate(nextProps, nextState) {
-    const isUnrendered = !this.state.isIntersecting && (this.state.isHidden || this.props.cachedHeight);
-    const willBeUnrendered = !nextState.isIntersecting && (nextState.isHidden || nextProps.cachedHeight);
-    if (!!isUnrendered !== !!willBeUnrendered) {
-      // If we're going from rendered to unrendered (or vice versa) then update
-      return true;
-    }
-    // Otherwise, diff based on props
-    const propsToDiff = isUnrendered ? updateOnPropsForUnrendered : updateOnPropsForRendered;
-    return !propsToDiff.every(prop => is(nextProps[prop], this.props[prop]));
-  }
-
-  componentDidMount() {
-    const { intersectionObserverWrapper, id } = this.props;
-
-    intersectionObserverWrapper.observe(
-      id,
-      this.node,
-      this.handleIntersection,
-    );
-
-    this.componentMounted = true;
-  }
-
-  componentWillUnmount() {
-    const { intersectionObserverWrapper, id } = this.props;
-    intersectionObserverWrapper.unobserve(id, this.node);
-
-    this.componentMounted = false;
-  }
-
-  handleIntersection = (entry) => {
-    this.entry = entry;
-
-    scheduleIdleTask(this.calculateHeight);
-    this.setState(this.updateStateAfterIntersection);
-  }
-
-  updateStateAfterIntersection = (prevState) => {
-    if (prevState.isIntersecting !== false && !this.entry.isIntersecting) {
-      scheduleIdleTask(this.hideIfNotIntersecting);
-    }
-    return {
-      isIntersecting: this.entry.isIntersecting,
-      isHidden: false,
-    };
-  }
-
-  calculateHeight = () => {
-    const { onHeightChange, saveHeightKey, id } = this.props;
-    // save the height of the fully-rendered element (this is expensive
-    // on Chrome, where we need to fall back to getBoundingClientRect)
-    this.height = getRectFromEntry(this.entry).height;
-
-    if (onHeightChange && saveHeightKey) {
-      onHeightChange(saveHeightKey, id, this.height);
-    }
-  }
-
-  hideIfNotIntersecting = () => {
-    if (!this.componentMounted) {
-      return;
-    }
-
-    // When the browser gets a chance, test if we're still not intersecting,
-    // and if so, set our isHidden to true to trigger an unrender. The point of
-    // this is to save DOM nodes and avoid using up too much memory.
-    this.setState((prevState) => ({ isHidden: !prevState.isIntersecting }));
-  }
-
-  handleRef = (node) => {
-    this.node = node;
-  }
-
-  render() {
-    const { children, id, index, listLength, cachedHeight } = this.props;
-    const { isIntersecting, isHidden } = this.state;
-
-    if (!isIntersecting && (isHidden || cachedHeight)) {
-      return (
-        <article
-          ref={this.handleRef}
-          aria-posinset={index + 1}
-          aria-setsize={listLength}
-          style={{ height: `${this.height || cachedHeight}px`, opacity: 0, overflow: 'hidden' }}
-          data-id={id}
-          tabIndex='0'
-        >
-          {children && React.cloneElement(children, { hidden: true })}
-        </article>
-      );
-    }
-
-    return (
-      <article ref={this.handleRef} aria-posinset={index + 1} aria-setsize={listLength} data-id={id} tabIndex='0'>
-        {children && React.cloneElement(children, { hidden: false })}
-      </article>
-    );
-  }
-
-}

app/soapbox/containers/intersection_observer_article_container.js

@@ -1,18 +0,0 @@
-import { connect } from 'react-redux';
-
-import { setHeight } from '../actions/height_cache';
-import IntersectionObserverArticle from '../components/intersection_observer_article';
-
-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/soapbox/features/ui/index.js

@@ -35,7 +35,6 @@ import { fetchFollowRequests } from '../../actions/accounts';
 import { fetchReports, fetchUsers, fetchConfig } from '../../actions/admin';
 import { uploadCompose, resetCompose } from '../../actions/compose';
 import { fetchFilters } from '../../actions/filters';
-import { clearHeight } from '../../actions/height_cache';
 import { openModal } from '../../actions/modals';
 import { expandNotifications } from '../../actions/notifications';
 import { fetchScheduledStatuses } from '../../actions/scheduled_statuses';
@@ -187,7 +186,6 @@ class SwitchingColumnsArea extends React.PureComponent {
   static propTypes = {
     children: PropTypes.node,
     location: PropTypes.object,
-    onLayoutChange: PropTypes.func.isRequired,
     soapbox: ImmutablePropTypes.record.isRequired,
     features: PropTypes.object.isRequired,
   };
@@ -205,9 +203,6 @@ class SwitchingColumnsArea extends React.PureComponent {
   }
 
   handleResize = debounce(() => {
-    // The cached heights are no longer accurate, invalidate
-    this.props.onLayoutChange();
-
     this.setState({ mobile: isMobile(window.innerWidth) });
   }, 500, {
     trailing: true,
@@ -408,11 +403,6 @@ class UI extends React.PureComponent {
     mobile: isMobile(window.innerWidth),
   };
 
-  handleLayoutChange = () => {
-    // The cached heights are no longer accurate, invalidate
-    this.props.dispatch(clearHeight());
-  }
-
   handleDragEnter = (e) => {
     e.preventDefault();
 
@@ -756,7 +746,7 @@ class UI extends React.PureComponent {
           <div className='z-10 flex flex-col'>
             <Navbar />
 
-            <SwitchingColumnsArea location={location} onLayoutChange={this.handleLayoutChange} soapbox={soapbox} features={features}>
+            <SwitchingColumnsArea location={location} soapbox={soapbox} features={features}>
               {children}
             </SwitchingColumnsArea>
 

app/soapbox/features/ui/util/get_rect_from_entry.js

@@ -1,21 +0,0 @@
-
-// Get the bounding client rect from an IntersectionObserver entry.
-// This is to work around a bug in Chrome: https://crbug.com/737228
-
-let hasBoundingRectBug;
-
-function getRectFromEntry(entry) {
-  if (typeof hasBoundingRectBug !== 'boolean') {
-    const boundingRect = entry.target.getBoundingClientRect();
-    const observerRect = entry.boundingClientRect;
-    hasBoundingRectBug = boundingRect.height !== observerRect.height ||
-      boundingRect.top !== observerRect.top ||
-      boundingRect.width !== observerRect.width ||
-      boundingRect.bottom !== observerRect.bottom ||
-      boundingRect.left !== observerRect.left ||
-      boundingRect.right !== observerRect.right;
-  }
-  return hasBoundingRectBug ? entry.target.getBoundingClientRect() : entry.boundingClientRect;
-}
-
-export default getRectFromEntry;

app/soapbox/features/ui/util/intersection_observer_wrapper.js

@@ -1,57 +0,0 @@
-// Wrapper for IntersectionObserver in order to make working with it
-// a bit easier. We also follow this performance advice:
-// "If you need to observe multiple elements, it is both possible and
-// advised to observe multiple elements using the same IntersectionObserver
-// instance by calling observe() multiple times."
-// https://developers.google.com/web/updates/2016/04/intersectionobserver
-
-class IntersectionObserverWrapper {
-
-  callbacks = {};
-  observerBacklog = [];
-  observer = null;
-
-  connect(options) {
-    const onIntersection = (entries) => {
-      entries.forEach(entry => {
-        const id = entry.target.getAttribute('data-id');
-        if (this.callbacks[id]) {
-          this.callbacks[id](entry);
-        }
-      });
-    };
-
-    this.observer = new IntersectionObserver(onIntersection, options);
-    this.observerBacklog.forEach(([ id, node, callback ]) => {
-      this.observe(id, node, callback);
-    });
-    this.observerBacklog = null;
-  }
-
-  observe(id, node, callback) {
-    if (!this.observer) {
-      this.observerBacklog.push([ id, node, callback ]);
-    } else {
-      this.callbacks[id] = callback;
-      this.observer.observe(node);
-    }
-  }
-
-  unobserve(id, node) {
-    if (this.observer) {
-      delete this.callbacks[id];
-      this.observer.unobserve(node);
-    }
-  }
-
-  disconnect() {
-    if (this.observer) {
-      this.callbacks = {};
-      this.observer.disconnect();
-      this.observer = null;
-    }
-  }
-
-}
-
-export default IntersectionObserverWrapper;

app/soapbox/reducers/__tests__/height_cache-test.js

@@ -1,14 +0,0 @@
-import { Map as ImmutableMap } from 'immutable';
-
-import reducer from '../height_cache';
-import { HEIGHT_CACHE_CLEAR } from '../height_cache';
-
-describe('height_cache reducer', () => {
-  it('should return the initial state', () => {
-    expect(reducer(undefined, {})).toEqual(ImmutableMap());
-  });
-
-  it('should handle HEIGHT_CACHE_CLEAR', () => {
-    expect(reducer(undefined, { type: HEIGHT_CACHE_CLEAR })).toEqual(ImmutableMap());
-  });
-});

app/soapbox/reducers/height_cache.js

@@ -1,24 +0,0 @@
-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/soapbox/reducers/index.ts

@@ -28,7 +28,6 @@ import group_editor from './group_editor';
 import group_lists from './group_lists';
 import group_relationships from './group_relationships';
 import groups from './groups';
-import height_cache from './height_cache';
 import identity_proofs from './identity_proofs';
 import instance from './instance';
 import listAdder from './list_adder';
@@ -83,7 +82,6 @@ const reducers = {
   compose,
   search,
   notifications,
-  height_cache,
   custom_emojis,
   identity_proofs,
   lists,