Improve switch room rendering

res/css/structures/_RoomView.scss

@@ -237,6 +237,7 @@ hr.mx_RoomView_myReadMarker {
     position: relative;
     top: -1px;
     z-index: 1;
+    will-change: width;
     transition: width 400ms easeinsine 1s, opacity 400ms easeinsine 1s;
     width: 99%;
     opacity: 1;

res/css/views/rooms/_IRCLayout.scss

@@ -115,8 +115,7 @@ $irc-line-height: $font-18px;
         .mx_EventTile_line {
             .mx_EventTile_e2eIcon,
             .mx_TextualEvent,
-            .mx_MTextBody,
-            .mx_ReplyThread_wrapper_empty {
+            .mx_MTextBody {
                 display: inline-block;
             }
         }
@@ -177,16 +176,13 @@ $irc-line-height: $font-18px;
     .mx_SenderProfile_hover {
         background-color: $primary-bg-color;
         overflow: hidden;
+        display: flex;
 
-        > span {
-            display: flex;
-
-            > .mx_SenderProfile_name {
-                overflow: hidden;
-                text-overflow: ellipsis;
-                min-width: var(--name-width);
-                text-align: end;
-            }
+        > .mx_SenderProfile_name {
+            overflow: hidden;
+            text-overflow: ellipsis;
+            min-width: var(--name-width);
+            text-align: end;
         }
     }
 

res/css/views/rooms/_RoomBreadcrumbs.scss

@@ -32,14 +32,14 @@ limitations under the License.
     // first triggering the enter state with the newest breadcrumb off screen (-40px) then
     // sliding it into view.
     &.mx_RoomBreadcrumbs-enter {
-        margin-left: -40px; // 32px for the avatar, 8px for the margin
+        transform: translateX(-40px); // 32px for the avatar, 8px for the margin
     }
     &.mx_RoomBreadcrumbs-enter-active {
-        margin-left: 0;
+        transform: translateX(0);
 
         // Timing function is as-requested by design.
         // NOTE: The transition time MUST match the value passed to CSSTransition!
-        transition: margin-left 640ms cubic-bezier(0.66, 0.02, 0.36, 1);
+        transition: transform 640ms cubic-bezier(0.66, 0.02, 0.36, 1);
     }
 
     .mx_RoomBreadcrumbs_placeholder {

src/components/structures/MessagePanel.js

@@ -645,39 +645,37 @@ export default class MessagePanel extends React.Component {
 
         // use txnId as key if available so that we don't remount during sending
         ret.push(
-            <li
-                key={mxEv.getTxnId() || eventId}
-                ref={this._collectEventNode.bind(this, eventId)}
-                data-scroll-tokens={scrollToken}
-            >
-                <TileErrorBoundary mxEvent={mxEv}>
-                    <EventTile
-                        mxEvent={mxEv}
-                        continuation={continuation}
-                        isRedacted={mxEv.isRedacted()}
-                        replacingEventId={mxEv.replacingEventId()}
-                        editState={isEditing && this.props.editState}
-                        onHeightChanged={this._onHeightChanged}
-                        readReceipts={readReceipts}
-                        readReceiptMap={this._readReceiptMap}
-                        showUrlPreview={this.props.showUrlPreview}
-                        checkUnmounting={this._isUnmounting}
-                        eventSendStatus={mxEv.getAssociatedStatus()}
-                        tileShape={this.props.tileShape}
-                        isTwelveHour={this.props.isTwelveHour}
-                        permalinkCreator={this.props.permalinkCreator}
-                        last={last}
-                        lastInSection={willWantDateSeparator}
-                        lastSuccessful={isLastSuccessful}
-                        isSelectedEvent={highlight}
-                        getRelationsForEvent={this.props.getRelationsForEvent}
-                        showReactions={this.props.showReactions}
-                        layout={this.props.layout}
-                        enableFlair={this.props.enableFlair}
-                        showReadReceipts={this.props.showReadReceipts}
-                    />
-                </TileErrorBoundary>
-            </li>,
+            <TileErrorBoundary key={mxEv.getTxnId() || eventId} mxEvent={mxEv}>
+                <EventTile
+                    as="li"
+                    data-scroll-tokens={scrollToken}
+                    ref={this._collectEventNode.bind(this, eventId)}
+                    alwaysShowTimestamps={this.props.alwaysShowTimestamps}
+                    mxEvent={mxEv}
+                    continuation={continuation}
+                    isRedacted={mxEv.isRedacted()}
+                    replacingEventId={mxEv.replacingEventId()}
+                    editState={isEditing && this.props.editState}
+                    onHeightChanged={this._onHeightChanged}
+                    readReceipts={readReceipts}
+                    readReceiptMap={this._readReceiptMap}
+                    showUrlPreview={this.props.showUrlPreview}
+                    checkUnmounting={this._isUnmounting}
+                    eventSendStatus={mxEv.getAssociatedStatus()}
+                    tileShape={this.props.tileShape}
+                    isTwelveHour={this.props.isTwelveHour}
+                    permalinkCreator={this.props.permalinkCreator}
+                    last={last}
+                    lastInSection={willWantDateSeparator}
+                    lastSuccessful={isLastSuccessful}
+                    isSelectedEvent={highlight}
+                    getRelationsForEvent={this.props.getRelationsForEvent}
+                    showReactions={this.props.showReactions}
+                    layout={this.props.layout}
+                    enableFlair={this.props.enableFlair}
+                    showReadReceipts={this.props.showReadReceipts}
+                />
+            </TileErrorBoundary>,
         );
 
         return ret;
@@ -779,7 +777,7 @@ export default class MessagePanel extends React.Component {
     }
 
     _collectEventNode = (eventId, node) => {
-        this.eventNodes[eventId] = node;
+        this.eventNodes[eventId] = node?.ref?.current;
     }
 
     // once dynamic content in the events load, make the scrollPanel check the

src/components/structures/RoomView.tsx

@@ -83,6 +83,7 @@ import { objectHasDiff } from "../../utils/objects";
 import SpaceRoomView from "./SpaceRoomView";
 import { IOpts } from "../../createRoom";
 import {replaceableComponent} from "../../utils/replaceableComponent";
+import { omit } from 'lodash';
 import UIStore from "../../stores/UIStore";
 
 const DEBUG = false;
@@ -176,6 +177,7 @@ export interface IState {
     statusBarVisible: boolean;
     // We load this later by asking the js-sdk to suggest a version for us.
     // This object is the result of Room#getRecommendedVersion()
+
     upgradeRecommendation?: {
         version: string;
         needsUpgrade: boolean;
@@ -529,7 +531,20 @@ export default class RoomView extends React.Component<IProps, IState> {
     }
 
     shouldComponentUpdate(nextProps, nextState) {
-        return (objectHasDiff(this.props, nextProps) || objectHasDiff(this.state, nextState));
+        const hasPropsDiff = objectHasDiff(this.props, nextProps);
+
+        // React only shallow comparison and we only want to trigger
+        // a component re-render if a room requires an upgrade
+        const newUpgradeRecommendation = nextState.upgradeRecommendation || {}
+
+        const state = omit(this.state, ['upgradeRecommendation']);
+        const newState = omit(nextState, ['upgradeRecommendation'])
+
+        const hasStateDiff =
+            objectHasDiff(state, newState) ||
+            (newUpgradeRecommendation.needsUpgrade === true)
+
+        return hasPropsDiff || hasStateDiff;
     }
 
     componentDidUpdate() {
@@ -812,7 +827,7 @@ export default class RoomView extends React.Component<IProps, IState> {
     };
 
     private onEvent = (ev) => {
-        if (ev.isBeingDecrypted() || ev.isDecryptionFailure() || ev.shouldAttemptDecryption()) return;
+        if (ev.isBeingDecrypted() || ev.isDecryptionFailure()) return;
         this.handleEffects(ev);
     };
 

src/components/structures/TimelinePanel.js

@@ -36,7 +36,6 @@ import shouldHideEvent from '../../shouldHideEvent';
 import EditorStateTransfer from '../../utils/EditorStateTransfer';
 import {haveTileForEvent} from "../views/rooms/EventTile";
 import {UIFeature} from "../../settings/UIFeature";
-import {objectHasDiff} from "../../utils/objects";
 import {replaceableComponent} from "../../utils/replaceableComponent";
 import { arrayFastClone } from "../../utils/arrays";
 
@@ -265,30 +264,6 @@ class TimelinePanel extends React.Component {
         }
     }
 
-    shouldComponentUpdate(nextProps, nextState) {
-        if (objectHasDiff(this.props, nextProps)) {
-            if (DEBUG) {
-                console.group("Timeline.shouldComponentUpdate: props change");
-                console.log("props before:", this.props);
-                console.log("props after:", nextProps);
-                console.groupEnd();
-            }
-            return true;
-        }
-
-        if (objectHasDiff(this.state, nextState)) {
-            if (DEBUG) {
-                console.group("Timeline.shouldComponentUpdate: state change");
-                console.log("state before:", this.state);
-                console.log("state after:", nextState);
-                console.groupEnd();
-            }
-            return true;
-        }
-
-        return false;
-    }
-
     componentWillUnmount() {
         // set a boolean to say we've been unmounted, which any pending
         // promises can use to throw away their results.

src/components/structures/ToastContainer.tsx

@@ -55,6 +55,7 @@ export default class ToastContainer extends React.Component<{}, IState> {
         const totalCount = this.state.toasts.length;
         const isStacked = totalCount > 1;
         let toast;
+        let containerClasses;
         if (totalCount !== 0) {
             const topToast = this.state.toasts[0];
             const {title, icon, key, component, className, props} = topToast;
@@ -79,16 +80,17 @@ export default class ToastContainer extends React.Component<{}, IState> {
                 </div>
                 <div className="mx_Toast_body">{React.createElement(component, toastProps)}</div>
             </div>);
-        }
-
-        const containerClasses = classNames("mx_ToastContainer", {
-            "mx_ToastContainer_stacked": isStacked,
-        });
 
-        return (
-            <div className={containerClasses} role="alert">
-                {toast}
-            </div>
-        );
+            containerClasses = classNames("mx_ToastContainer", {
+                "mx_ToastContainer_stacked": isStacked,
+            });
+        }
+        return toast
+            ? (
+                <div className={containerClasses} role="alert">
+                    {toast}
+                </div>
+            )
+            : null;
     }
 }

src/components/views/elements/AccessibleTooltipButton.tsx

@@ -73,7 +73,7 @@ export default class AccessibleTooltipButton extends React.PureComponent<IToolti
             tooltipClassName={classNames("mx_AccessibleTooltipButton_tooltip", tooltipClassName)}
             label={tooltip || title}
             yOffset={yOffset}
-        /> : <div />;
+        /> : null;
         return (
             <AccessibleButton
                 {...props}

src/components/views/elements/Flair.js

@@ -116,7 +116,7 @@ export default class Flair extends React.Component {
 
     render() {
         if (this.state.profiles.length === 0) {
-            return <span className="mx_Flair" />;
+            return null;
         }
         const avatars = this.state.profiles.map((profile, index) => {
             return <FlairAvatar key={index} groupProfile={profile} />;

src/components/views/elements/ReplyThread.js

@@ -214,7 +214,7 @@ export default class ReplyThread extends React.Component {
 
     static makeThread(parentEv, onHeightChanged, permalinkCreator, ref, layout) {
         if (!ReplyThread.getParentEventId(parentEv)) {
-            return <div className="mx_ReplyThread_wrapper_empty" />;
+            return null;
         }
         return <ReplyThread
             parentEv={parentEv}
@@ -269,36 +269,27 @@ export default class ReplyThread extends React.Component {
         const {parentEv} = this.props;
         // at time of making this component we checked that props.parentEv has a parentEventId
         const ev = await this.getEvent(ReplyThread.getParentEventId(parentEv));
+
         if (this.unmounted) return;
 
         if (ev) {
+            const loadedEv = await this.getNextEvent(ev);
             this.setState({
                 events: [ev],
-            }, this.loadNextEvent);
+                loadedEv,
+                loading: false,
+            });
         } else {
             this.setState({err: true});
         }
     }
 
-    async loadNextEvent() {
-        if (this.unmounted) return;
-        const ev = this.state.events[0];
-        const inReplyToEventId = ReplyThread.getParentEventId(ev);
-
-        if (!inReplyToEventId) {
-            this.setState({
-                loading: false,
-            });
-            return;
-        }
-
-        const loadedEv = await this.getEvent(inReplyToEventId);
-        if (this.unmounted) return;
-
-        if (loadedEv) {
-            this.setState({loadedEv});
-        } else {
-            this.setState({err: true});
+    async getNextEvent(ev) {
+        try {
+            const inReplyToEventId = ReplyThread.getParentEventId(ev);
+            return await this.getEvent(inReplyToEventId);
+        } catch (e) {
+            return null;
         }
     }
 
@@ -326,13 +317,18 @@ export default class ReplyThread extends React.Component {
         this.initialize();
     }
 
-    onQuoteClick() {
+    async onQuoteClick() {
         const events = [this.state.loadedEv, ...this.state.events];
 
+        let loadedEv = null;
+        if (events.length > 0) {
+            loadedEv = await this.getNextEvent(events[0]);
+        }
+
         this.setState({
-            loadedEv: null,
+            loadedEv,
             events,
-        }, this.loadNextEvent);
+        });
 
         dis.fire(Action.FocusComposer);
     }