RoomView.tsx

/*
Copyright 2015, 2016 OpenMarket Ltd
Copyright 2017 Vector Creations Ltd
Copyright 2018, 2019 New Vector Ltd
Copyright 2019 - 2022 The Matrix.org Foundation C.I.C.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

// TODO: This component is enormous! There's several things which could stand-alone:
//  - Search results component

import React, { createRef, ReactElement, ReactNode, RefObject, useContext } from 'react';
import classNames from 'classnames';
import { IRecommendedVersion, NotificationCountType, Room, RoomEvent } from "matrix-js-sdk/src/models/room";
import { IThreadBundledRelationship, MatrixEvent, MatrixEventEvent } from "matrix-js-sdk/src/models/event";
import { ISearchResults } from 'matrix-js-sdk/src/@types/search';
import { logger } from "matrix-js-sdk/src/logger";
import { EventTimeline } from 'matrix-js-sdk/src/models/event-timeline';
import { EventType } from 'matrix-js-sdk/src/@types/event';
import { RoomState, RoomStateEvent } from 'matrix-js-sdk/src/models/room-state';
import { EventTimelineSet } from "matrix-js-sdk/src/models/event-timeline-set";
import { CallState, MatrixCall } from "matrix-js-sdk/src/webrtc/call";
import { throttle } from "lodash";
import { MatrixError } from 'matrix-js-sdk/src/http-api';
import { ClientEvent } from "matrix-js-sdk/src/client";
import { CryptoEvent } from "matrix-js-sdk/src/crypto";
import { THREAD_RELATION_TYPE } from 'matrix-js-sdk/src/models/thread';
import { HistoryVisibility } from 'matrix-js-sdk/src/@types/partials';

import shouldHideEvent from '../../shouldHideEvent';
import { _t } from '../../languageHandler';
import { RoomPermalinkCreator } from '../../utils/permalinks/Permalinks';
import ResizeNotifier from '../../utils/ResizeNotifier';
import ContentMessages from '../../ContentMessages';
import Modal from '../../Modal';
import { LegacyCallHandlerEvent } from '../../LegacyCallHandler';
import dis, { defaultDispatcher } from '../../dispatcher/dispatcher';
import * as Rooms from '../../Rooms';
import eventSearch, { searchPagination } from '../../Searching';
import MainSplit from './MainSplit';
import RightPanel from './RightPanel';
import RoomScrollStateStore, { ScrollState } from '../../stores/RoomScrollStateStore';
import WidgetEchoStore from '../../stores/WidgetEchoStore';
import SettingsStore from "../../settings/SettingsStore";
import { Layout } from "../../settings/enums/Layout";
import AccessibleButton from "../views/elements/AccessibleButton";
import RoomContext, { TimelineRenderingType } from "../../contexts/RoomContext";
import { E2EStatus, shieldStatusForRoom } from '../../utils/ShieldUtils';
import { Action } from "../../dispatcher/actions";
import { IMatrixClientCreds } from "../../MatrixClientPeg";
import ScrollPanel from "./ScrollPanel";
import TimelinePanel from "./TimelinePanel";
import ErrorBoundary from "../views/elements/ErrorBoundary";
import RoomPreviewBar from "../views/rooms/RoomPreviewBar";
import RoomPreviewCard from "../views/rooms/RoomPreviewCard";
import SearchBar, { SearchScope } from "../views/rooms/SearchBar";
import RoomUpgradeWarningBar from "../views/rooms/RoomUpgradeWarningBar";
import AuxPanel from "../views/rooms/AuxPanel";
import RoomHeader from "../views/rooms/RoomHeader";
import { XOR } from "../../@types/common";
import { IOOBData, IThreepidInvite } from "../../stores/ThreepidInviteStore";
import EffectsOverlay from "../views/elements/EffectsOverlay";
import { containsEmoji } from '../../effects/utils';
import { CHAT_EFFECTS } from '../../effects';
import { CallView } from "../views/voip/CallView";
import { UPDATE_EVENT } from "../../stores/AsyncStore";
import Notifier from "../../Notifier";
import { showToast as showNotificationsToast } from "../../toasts/DesktopNotificationsToast";
import { Container, WidgetLayoutStore } from "../../stores/widgets/WidgetLayoutStore";
import { getKeyBindingsManager } from '../../KeyBindingsManager';
import { objectHasDiff } from "../../utils/objects";
import SpaceRoomView from "./SpaceRoomView";
import { IOpts } from "../../createRoom";
import EditorStateTransfer from "../../utils/EditorStateTransfer";
import ErrorDialog from '../views/dialogs/ErrorDialog';
import SearchResultTile from '../views/rooms/SearchResultTile';
import Spinner from "../views/elements/Spinner";
import UploadBar from './UploadBar';
import RoomStatusBar from "./RoomStatusBar";
import MessageComposer from '../views/rooms/MessageComposer';
import JumpToBottomButton from "../views/rooms/JumpToBottomButton";
import TopUnreadMessagesBar from "../views/rooms/TopUnreadMessagesBar";
import { fetchInitialEvent } from "../../utils/EventUtils";
import { ComposerInsertPayload, ComposerType } from "../../dispatcher/payloads/ComposerInsertPayload";
import AppsDrawer from '../views/rooms/AppsDrawer';
import { RightPanelPhases } from '../../stores/right-panel/RightPanelStorePhases';
import { ActionPayload } from "../../dispatcher/payloads";
import { KeyBindingAction } from "../../accessibility/KeyboardShortcuts";
import { ViewRoomPayload } from "../../dispatcher/payloads/ViewRoomPayload";
import { JoinRoomPayload } from "../../dispatcher/payloads/JoinRoomPayload";
import { DoAfterSyncPreparedPayload } from '../../dispatcher/payloads/DoAfterSyncPreparedPayload';
import FileDropTarget from './FileDropTarget';
import Measured from '../views/elements/Measured';
import { FocusComposerPayload } from '../../dispatcher/payloads/FocusComposerPayload';
import { haveRendererForEvent } from "../../events/EventTileFactory";
import { LocalRoom, LocalRoomState } from '../../models/LocalRoom';
import { createRoomFromLocalRoom } from '../../utils/direct-messages';
import NewRoomIntro from '../views/rooms/NewRoomIntro';
import EncryptionEvent from '../views/messages/EncryptionEvent';
import { StaticNotificationState } from '../../stores/notifications/StaticNotificationState';
import { isLocalRoom } from '../../utils/localRoom/isLocalRoom';
import { ShowThreadPayload } from "../../dispatcher/payloads/ShowThreadPayload";
import { RoomStatusBarUnsentMessages } from './RoomStatusBarUnsentMessages';
import { LargeLoader } from './LargeLoader';
import { isVideoRoom } from '../../utils/video-rooms';
import { SDKContext } from '../../contexts/SDKContext';
import { CallStore, CallStoreEvent } from "../../stores/CallStore";
import { Call } from "../../models/Call";

const DEBUG = false;
let debuglog = function(msg: string) {};

const BROWSER_SUPPORTS_SANDBOX = 'sandbox' in document.createElement('iframe');

if (DEBUG) {
    // using bind means that we get to keep useful line numbers in the console
    debuglog = logger.log.bind(console);
}

interface IRoomProps {
    threepidInvite: IThreepidInvite;
    oobData?: IOOBData;

    resizeNotifier: ResizeNotifier;
    justCreatedOpts?: IOpts;

    forceTimeline?: boolean; // should we force access to the timeline, overriding (for eg) spaces

    // Called with the credentials of a registered user (if they were a ROU that transitioned to PWLU)
    onRegistered?(credentials: IMatrixClientCreds): void;
}

// This defines the content of the mainSplit.
// If the mainSplit does not contain the Timeline, the chat is shown in the right panel.
enum MainSplitContentType {
    Timeline,
    MaximisedWidget,
    Call,
}
export interface IRoomState {
    room?: Room;
    roomId?: string;
    roomAlias?: string;
    roomLoading: boolean;
    peekLoading: boolean;
    shouldPeek: boolean;
    // used to trigger a rerender in TimelinePanel once the members are loaded,
    // so RR are rendered again (now with the members available), ...
    membersLoaded: boolean;
    // The event to be scrolled to initially
    initialEventId?: string;
    // The offset in pixels from the event with which to scroll vertically
    initialEventPixelOffset?: number;
    // Whether to highlight the event scrolled to
    isInitialEventHighlighted?: boolean;
    // Whether to scroll the event into view
    initialEventScrollIntoView?: boolean;
    replyToEvent?: MatrixEvent;
    numUnreadMessages: number;
    searchTerm?: string;
    searchScope?: SearchScope;
    searchResults?: XOR<{}, ISearchResults>;
    searchHighlights?: string[];
    searchInProgress?: boolean;
    callState?: CallState;
    activeCall: Call | null;
    canPeek: boolean;
    canSelfRedact: boolean;
    showApps: boolean;
    isPeeking: boolean;
    showRightPanel: boolean;
    // error object, as from the matrix client/server API
    // If we failed to load information about the room,
    // store the error here.
    roomLoadError?: MatrixError;
    // Have we sent a request to join the room that we're waiting to complete?
    joining: boolean;
    // this is true if we are fully scrolled-down, and are looking at
    // the end of the live timeline. It has the effect of hiding the
    // 'scroll to bottom' knob, among a couple of other things.
    atEndOfLiveTimeline?: boolean;
    showTopUnreadMessagesBar: boolean;
    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?: IRecommendedVersion;
    canReact: boolean;
    canSendMessages: boolean;
    tombstone?: MatrixEvent;
    resizing: boolean;
    layout: Layout;
    lowBandwidth: boolean;
    alwaysShowTimestamps: boolean;
    showTwelveHourTimestamps: boolean;
    readMarkerInViewThresholdMs: number;
    readMarkerOutOfViewThresholdMs: number;
    showHiddenEvents: boolean;
    showReadReceipts: boolean;
    showRedactions: boolean;
    showJoinLeaves: boolean;
    showAvatarChanges: boolean;
    showDisplaynameChanges: boolean;
    matrixClientIsReady: boolean;
    showUrlPreview?: boolean;
    e2eStatus?: E2EStatus;
    rejecting?: boolean;
    rejectError?: Error;
    hasPinnedWidgets?: boolean;
    mainSplitContentType?: MainSplitContentType;
    // whether or not a spaces context switch brought us here,
    // if it did we don't want the room to be marked as read as soon as it is loaded.
    wasContextSwitch?: boolean;
    editState?: EditorStateTransfer;
    timelineRenderingType: TimelineRenderingType;
    threadId?: string;
    liveTimeline?: EventTimeline;
    narrow: boolean;
}

interface LocalRoomViewProps {
    resizeNotifier: ResizeNotifier;
    permalinkCreator: RoomPermalinkCreator;
    roomView: RefObject<HTMLElement>;
    onFileDrop: (dataTransfer: DataTransfer) => Promise<void>;
}

/**
 * Local room view. Uses only the bits necessary to display a local room view like room header or composer.
 *
 * @param {LocalRoomViewProps} props Room view props
 * @returns {ReactElement}
 */
function LocalRoomView(props: LocalRoomViewProps): ReactElement {
    const context = useContext(RoomContext);
    const room = context.room as LocalRoom;
    const encryptionEvent = context.room.currentState.getStateEvents(EventType.RoomEncryption)[0];
    let encryptionTile: ReactNode;

    if (encryptionEvent) {
        encryptionTile = <EncryptionEvent mxEvent={encryptionEvent} />;
    }

    const onRetryClicked = () => {
        room.state = LocalRoomState.NEW;
        defaultDispatcher.dispatch({
            action: "local_room_event",
            roomId: room.roomId,
        });
    };

    let statusBar: ReactElement;
    let composer: ReactElement;

    if (room.isError) {
        const buttons = (
            <AccessibleButton onClick={onRetryClicked} className="mx_RoomStatusBar_unsentRetry">
                { _t("Retry") }
            </AccessibleButton>
        );

        statusBar = <RoomStatusBarUnsentMessages
            title={_t("Some of your messages have not been sent")}
            notificationState={StaticNotificationState.RED_EXCLAMATION}
            buttons={buttons}
        />;
    } else {
        composer = <MessageComposer
            room={context.room}
            resizeNotifier={props.resizeNotifier}
            permalinkCreator={props.permalinkCreator}
        />;
    }

    return (
        <div className="mx_RoomView mx_RoomView--local">
            <ErrorBoundary>
                <RoomHeader
                    room={context.room}
                    searchInfo={null}
                    inRoom={true}
                    onSearchClick={null}
                    onInviteClick={null}
                    onForgetClick={null}
                    e2eStatus={E2EStatus.Normal}
                    onAppsClick={null}
                    appsShown={false}
                    excludedRightPanelPhaseButtons={[]}
                    showButtons={false}
                    enableRoomOptionsMenu={false}
                    viewingCall={false}
                    activeCall={null}
                />
                <main className="mx_RoomView_body" ref={props.roomView}>
                    <FileDropTarget parent={props.roomView.current} onFileDrop={props.onFileDrop} />
                    <div className="mx_RoomView_timeline">
                        <ScrollPanel
                            className="mx_RoomView_messagePanel"
                            resizeNotifier={props.resizeNotifier}
                        >
                            { encryptionTile }
                            <NewRoomIntro />
                        </ScrollPanel>
                    </div>
                    { statusBar }
                    { composer }
                </main>
            </ErrorBoundary>
        </div>
    );
}

interface ILocalRoomCreateLoaderProps {
    names: string;
    resizeNotifier: ResizeNotifier;
}

/**
 * Room create loader view displaying a message and a spinner.
 *
 * @param {ILocalRoomCreateLoaderProps} props Room view props
 * @return {ReactElement}
 */
function LocalRoomCreateLoader(props: ILocalRoomCreateLoaderProps): ReactElement {
    const context = useContext(RoomContext);
    const text = _t("We're creating a room with %(names)s", { names: props.names });
    return (
        <div className="mx_RoomView mx_RoomView--local">
            <ErrorBoundary>
                <RoomHeader
                    room={context.room}
                    searchInfo={null}
                    inRoom={true}
                    onSearchClick={null}
                    onInviteClick={null}
                    onForgetClick={null}
                    e2eStatus={E2EStatus.Normal}
                    onAppsClick={null}
                    appsShown={false}
                    excludedRightPanelPhaseButtons={[]}
                    showButtons={false}
                    enableRoomOptionsMenu={false}
                    viewingCall={false}
                    activeCall={null}
                />
                <div className="mx_RoomView_body">
                    <LargeLoader text={text} />
                </div>
            </ErrorBoundary>
        </div>
    );
}

export class RoomView extends React.Component<IRoomProps, IRoomState> {
    private readonly dispatcherRef: string;
    private settingWatchers: string[];

    private unmounted = false;
    private permalinkCreators: Record<string, RoomPermalinkCreator> = {};
    private searchId: number;

    private roomView = createRef<HTMLElement>();
    private searchResultsPanel = createRef<ScrollPanel>();
    private messagePanel: TimelinePanel;
    private roomViewBody = createRef<HTMLDivElement>();

    static contextType = SDKContext;
    public context!: React.ContextType<typeof SDKContext>;

    constructor(props: IRoomProps, context: React.ContextType<typeof SDKContext>) {
        super(props, context);

        const llMembers = context.client.hasLazyLoadMembersEnabled();
        this.state = {
            roomId: null,
            roomLoading: true,
            peekLoading: false,
            shouldPeek: true,
            membersLoaded: !llMembers,
            numUnreadMessages: 0,
            searchResults: null,
            callState: null,
            activeCall: null,
            canPeek: false,
            canSelfRedact: false,
            showApps: false,
            isPeeking: false,
            showRightPanel: false,
            joining: false,
            showTopUnreadMessagesBar: false,
            statusBarVisible: false,
            canReact: false,
            canSendMessages: false,
            resizing: false,
            layout: SettingsStore.getValue("layout"),
            lowBandwidth: SettingsStore.getValue("lowBandwidth"),
            alwaysShowTimestamps: SettingsStore.getValue("alwaysShowTimestamps"),
            showTwelveHourTimestamps: SettingsStore.getValue("showTwelveHourTimestamps"),
            readMarkerInViewThresholdMs: SettingsStore.getValue("readMarkerInViewThresholdMs"),
            readMarkerOutOfViewThresholdMs: SettingsStore.getValue("readMarkerOutOfViewThresholdMs"),
            showHiddenEvents: SettingsStore.getValue("showHiddenEventsInTimeline"),
            showReadReceipts: true,
            showRedactions: true,
            showJoinLeaves: true,
            showAvatarChanges: true,
            showDisplaynameChanges: true,
            matrixClientIsReady: context.client?.isInitialSyncComplete(),
            mainSplitContentType: MainSplitContentType.Timeline,
            timelineRenderingType: TimelineRenderingType.Room,
            liveTimeline: undefined,
            narrow: false,
        };

        this.dispatcherRef = dis.register(this.onAction);
        context.client.on(ClientEvent.Room, this.onRoom);
        context.client.on(RoomEvent.Timeline, this.onRoomTimeline);
        context.client.on(RoomEvent.TimelineReset, this.onRoomTimelineReset);
        context.client.on(RoomEvent.Name, this.onRoomName);
        context.client.on(RoomStateEvent.Events, this.onRoomStateEvents);
        context.client.on(RoomStateEvent.Update, this.onRoomStateUpdate);
        context.client.on(RoomEvent.MyMembership, this.onMyMembership);
        context.client.on(CryptoEvent.KeyBackupStatus, this.onKeyBackupStatus);
        context.client.on(CryptoEvent.DeviceVerificationChanged, this.onDeviceVerificationChanged);
        context.client.on(CryptoEvent.UserTrustStatusChanged, this.onUserVerificationChanged);
        context.client.on(CryptoEvent.KeysChanged, this.onCrossSigningKeysChanged);
        context.client.on(MatrixEventEvent.Decrypted, this.onEventDecrypted);
        // Start listening for RoomViewStore updates
        context.roomViewStore.on(UPDATE_EVENT, this.onRoomViewStoreUpdate);

        context.rightPanelStore.on(UPDATE_EVENT, this.onRightPanelStoreUpdate);

        WidgetEchoStore.on(UPDATE_EVENT, this.onWidgetEchoStoreUpdate);
        context.widgetStore.on(UPDATE_EVENT, this.onWidgetStoreUpdate);

        CallStore.instance.on(CallStoreEvent.ActiveCalls, this.onActiveCalls);

        this.props.resizeNotifier.on("isResizing", this.onIsResizing);

        this.settingWatchers = [
            SettingsStore.watchSetting("layout", null, (...[,,, value]) =>
                this.setState({ layout: value as Layout }),
            ),
            SettingsStore.watchSetting("lowBandwidth", null, (...[,,, value]) =>
                this.setState({ lowBandwidth: value as boolean }),
            ),
            SettingsStore.watchSetting("alwaysShowTimestamps", null, (...[,,, value]) =>
                this.setState({ alwaysShowTimestamps: value as boolean }),
            ),
            SettingsStore.watchSetting("showTwelveHourTimestamps", null, (...[,,, value]) =>
                this.setState({ showTwelveHourTimestamps: value as boolean }),
            ),
            SettingsStore.watchSetting("readMarkerInViewThresholdMs", null, (...[,,, value]) =>
                this.setState({ readMarkerInViewThresholdMs: value as number }),
            ),
            SettingsStore.watchSetting("readMarkerOutOfViewThresholdMs", null, (...[,,, value]) =>
                this.setState({ readMarkerOutOfViewThresholdMs: value as number }),
            ),
            SettingsStore.watchSetting("showHiddenEventsInTimeline", null, (...[,,, value]) =>
                this.setState({ showHiddenEvents: value as boolean }),
            ),
            SettingsStore.watchSetting("urlPreviewsEnabled", null, this.onUrlPreviewsEnabledChange),
            SettingsStore.watchSetting("urlPreviewsEnabled_e2ee", null, this.onUrlPreviewsEnabledChange),
        ];
    }

    private onIsResizing = (resizing: boolean) => {
        this.setState({ resizing });
    };

    private onWidgetStoreUpdate = () => {
        if (!this.state.room) return;
        this.checkWidgets(this.state.room);
    };

    private onWidgetEchoStoreUpdate = () => {
        if (!this.state.room) return;
        this.checkWidgets(this.state.room);
    };

    private onWidgetLayoutChange = () => {
        if (!this.state.room) return;
        dis.dispatch({
            action: "appsDrawer",
            show: true,
        });
        if (this.context.widgetLayoutStore.hasMaximisedWidget(this.state.room)) {
            // Show chat in right panel when a widget is maximised
            this.context.rightPanelStore.setCard({ phase: RightPanelPhases.Timeline });
        }
        this.checkWidgets(this.state.room);
    };

    private checkWidgets = (room: Room): void => {
        this.setState({
            hasPinnedWidgets: this.context.widgetLayoutStore.hasPinnedWidgets(room),
            mainSplitContentType: this.getMainSplitContentType(room),
            showApps: this.shouldShowApps(room),
        });
    };

    private getMainSplitContentType = (room: Room) => {
        if (
            (SettingsStore.getValue("feature_group_calls") && this.context.roomViewStore.isViewingCall())
            || isVideoRoom(room)
        ) {
            return MainSplitContentType.Call;
        }
        if (this.context.widgetLayoutStore.hasMaximisedWidget(room)) {
            return MainSplitContentType.MaximisedWidget;
        }
        return MainSplitContentType.Timeline;
    };

    private onRoomViewStoreUpdate = async (initial?: boolean): Promise<void> => {
        if (this.unmounted) {
            return;
        }

        if (!initial && this.state.roomId !== this.context.roomViewStore.getRoomId()) {
            // RoomView explicitly does not support changing what room
            // is being viewed: instead it should just be re-mounted when
            // switching rooms. Therefore, if the room ID changes, we
            // ignore this. We either need to do this or add code to handle
            // saving the scroll position (otherwise we end up saving the
            // scroll position against the wrong room).

            // Given that doing the setState here would cause a bunch of
            // unnecessary work, we just ignore the change since we know
            // that if the current room ID has changed from what we thought
            // it was, it means we're about to be unmounted.
            return;
        }

        const roomId = this.context.roomViewStore.getRoomId();
        const room = this.context.client.getRoom(roomId);

        // This convoluted type signature ensures we get IntelliSense *and* correct typing
        const newState: Partial<IRoomState> & Pick<IRoomState, any> = {
            roomId,
            roomAlias: this.context.roomViewStore.getRoomAlias(),
            roomLoading: this.context.roomViewStore.isRoomLoading(),
            roomLoadError: this.context.roomViewStore.getRoomLoadError(),
            joining: this.context.roomViewStore.isJoining(),
            replyToEvent: this.context.roomViewStore.getQuotingEvent(),
            // we should only peek once we have a ready client
            shouldPeek: this.state.matrixClientIsReady && this.context.roomViewStore.shouldPeek(),
            showReadReceipts: SettingsStore.getValue("showReadReceipts", roomId),
            showRedactions: SettingsStore.getValue("showRedactions", roomId),
            showJoinLeaves: SettingsStore.getValue("showJoinLeaves", roomId),
            showAvatarChanges: SettingsStore.getValue("showAvatarChanges", roomId),
            showDisplaynameChanges: SettingsStore.getValue("showDisplaynameChanges", roomId),
            wasContextSwitch: this.context.roomViewStore.getWasContextSwitch(),
            mainSplitContentType: room === null ? undefined : this.getMainSplitContentType(room),
            initialEventId: null, // default to clearing this, will get set later in the method if needed
            showRightPanel: this.context.rightPanelStore.isOpenForRoom(roomId),
            activeCall: CallStore.instance.getActiveCall(roomId),
        };

        if (
            this.state.mainSplitContentType !== MainSplitContentType.Timeline
            && newState.mainSplitContentType === MainSplitContentType.Timeline
            && this.context.rightPanelStore.isOpen
            && this.context.rightPanelStore.currentCard.phase === RightPanelPhases.Timeline
            && this.context.rightPanelStore.roomPhaseHistory.some(card => (card.phase === RightPanelPhases.Timeline))
        ) {
            // We're returning to the main timeline, so hide the right panel timeline
            this.context.rightPanelStore.setCard({ phase: RightPanelPhases.RoomSummary });
            this.context.rightPanelStore.togglePanel(this.state.roomId ?? null);
            newState.showRightPanel = false;
        }

        const initialEventId = this.context.roomViewStore.getInitialEventId();
        if (initialEventId) {
            let initialEvent = room?.findEventById(initialEventId);
            // The event does not exist in the current sync data
            // We need to fetch it to know whether to route this request
            // to the main timeline or to a threaded one
            // In the current state, if a thread does not exist in the sync data
            // We will only display the event targeted by the `matrix.to` link
            // and the root event.
            // The rest will be lost for now, until the aggregation API on the server
            // becomes available to fetch a whole thread
            if (!initialEvent) {
                initialEvent = await fetchInitialEvent(
                    this.context.client,
                    roomId,
                    initialEventId,
                );
            }

            // If we have an initial event, we want to reset the event pixel offset to ensure it ends up
            // visible
            newState.initialEventPixelOffset = null;

            const thread = initialEvent?.getThread();
            if (thread && !initialEvent?.isThreadRoot) {
                dis.dispatch<ShowThreadPayload>({
                    action: Action.ShowThread,
                    rootEvent: thread.rootEvent,
                    initialEvent,
                    highlighted: this.context.roomViewStore.isInitialEventHighlighted(),
                    scroll_into_view: this.context.roomViewStore.initialEventScrollIntoView(),
                });
            } else {
                newState.initialEventId = initialEventId;
                newState.isInitialEventHighlighted = this.context.roomViewStore.isInitialEventHighlighted();
                newState.initialEventScrollIntoView = this.context.roomViewStore.initialEventScrollIntoView();

                if (thread && initialEvent?.isThreadRoot) {
                    dis.dispatch<ShowThreadPayload>({
                        action: Action.ShowThread,
                        rootEvent: thread.rootEvent,
                        initialEvent,
                        highlighted: this.context.roomViewStore.isInitialEventHighlighted(),
                        scroll_into_view: this.context.roomViewStore.initialEventScrollIntoView(),
                    });
                }
            }
        }

        // Add watchers for each of the settings we just looked up
        this.settingWatchers = this.settingWatchers.concat([
            SettingsStore.watchSetting("showReadReceipts", roomId, (...[,,, value]) =>
                this.setState({ showReadReceipts: value as boolean }),
            ),
            SettingsStore.watchSetting("showRedactions", roomId, (...[,,, value]) =>
                this.setState({ showRedactions: value as boolean }),
            ),
            SettingsStore.watchSetting("showJoinLeaves", roomId, (...[,,, value]) =>
                this.setState({ showJoinLeaves: value as boolean }),
            ),
            SettingsStore.watchSetting("showAvatarChanges", roomId, (...[,,, value]) =>
                this.setState({ showAvatarChanges: value as boolean }),
            ),
            SettingsStore.watchSetting("showDisplaynameChanges", roomId, (...[,,, value]) =>
                this.setState({ showDisplaynameChanges: value as boolean }),
            ),
        ]);

        if (!initial && this.state.shouldPeek && !newState.shouldPeek) {
            // Stop peeking because we have joined this room now
            this.context.client.stopPeeking();
        }

        // Temporary logging to diagnose https://github.com/vector-im/element-web/issues/4307
        logger.log(
            'RVS update:',
            newState.roomId,
            newState.roomAlias,
            'loading?', newState.roomLoading,
            'joining?', newState.joining,
            'initial?', initial,
            'shouldPeek?', newState.shouldPeek,
        );

        // NB: This does assume that the roomID will not change for the lifetime of
        // the RoomView instance
        if (initial) {
            newState.room = this.context.client.getRoom(newState.roomId);
            if (newState.room) {
                newState.showApps = this.shouldShowApps(newState.room);
                this.onRoomLoaded(newState.room);
            }
        }

        if (this.state.roomId === null && newState.roomId !== null) {
            // Get the scroll state for the new room

            // If an event ID wasn't specified, default to the one saved for this room
            // in the scroll state store. Assume initialEventPixelOffset should be set.
            if (!newState.initialEventId) {
                const roomScrollState = RoomScrollStateStore.getScrollState(newState.roomId);
                if (roomScrollState) {
                    newState.initialEventId = roomScrollState.focussedEvent;
                    newState.initialEventPixelOffset = roomScrollState.pixelOffset;
                }
            }
        }

        // Clear the search results when clicking a search result (which changes the
        // currently scrolled to event, this.state.initialEventId).
        if (this.state.initialEventId !== newState.initialEventId) {
            newState.searchResults = null;
        }

        this.setState(newState);
        // At this point, newState.roomId could be null (e.g. the alias might not
        // have been resolved yet) so anything called here must handle this case.

        // We pass the new state into this function for it to read: it needs to
        // observe the new state but we don't want to put it in the setState
        // callback because this would prevent the setStates from being batched,
        // ie. cause it to render RoomView twice rather than the once that is necessary.
        if (initial) {
            this.setupRoom(newState.room, newState.roomId, newState.joining, newState.shouldPeek);
        }
    };

    private onActiveCalls = () => {
        if (this.state.roomId === undefined) return;
        const activeCall = CallStore.instance.getActiveCall(this.state.roomId);

        if (activeCall === null) {
            // We disconnected from the call, so stop viewing it
            dis.dispatch<ViewRoomPayload>({
                action: Action.ViewRoom,
                room_id: this.state.roomId,
                view_call: false,
                metricsTrigger: undefined,
            }, true); // Synchronous so that CallView disappears immediately
        }

        this.setState({ activeCall });
    };

    private getRoomId = () => {
        // According to `onRoomViewStoreUpdate`, `state.roomId` can be null
        // if we have a room alias we haven't resolved yet. To work around this,
        // first we'll try the room object if it's there, and then fallback to
        // the bare room ID. (We may want to update `state.roomId` after
        // resolving aliases, so we could always trust it.)
        return this.state.room ? this.state.room.roomId : this.state.roomId;
    };

    private getPermalinkCreatorForRoom(room: Room) {
        if (this.permalinkCreators[room.roomId]) return this.permalinkCreators[room.roomId];

        this.permalinkCreators[room.roomId] = new RoomPermalinkCreator(room);
        if (this.state.room && room.roomId === this.state.room.roomId) {
            // We want to watch for changes in the creator for the primary room in the view, but
            // don't need to do so for search results.
            this.permalinkCreators[room.roomId].start();
        } else {
            this.permalinkCreators[room.roomId].load();
        }
        return this.permalinkCreators[room.roomId];
    }

    private stopAllPermalinkCreators() {
        if (!this.permalinkCreators) return;
        for (const roomId of Object.keys(this.permalinkCreators)) {
            this.permalinkCreators[roomId].stop();
        }
    }

    private setupRoom(room: Room, roomId: string, joining: boolean, shouldPeek: boolean) {
        // if this is an unknown room then we're in one of three states:
        // - This is a room we can peek into (search engine) (we can /peek)
        // - This is a room we can publicly join or were invited to. (we can /join)
        // - This is a room we cannot join at all. (no action can help us)
        // We can't try to /join because this may implicitly accept invites (!)
        // We can /peek though. If it fails then we present the join UI. If it
        // succeeds then great, show the preview (but we still may be able to /join!).
        // Note that peeking works by room ID and room ID only, as opposed to joining
        // which must be by alias or invite wherever possible (peeking currently does
        // not work over federation).

        // NB. We peek if we have never seen the room before (i.e. js-sdk does not know
        // about it). We don't peek in the historical case where we were joined but are
        // now not joined because the js-sdk peeking API will clobber our historical room,
        // making it impossible to indicate a newly joined room.
        if (!joining && roomId) {
            if (!room && shouldPeek) {
                logger.info("Attempting to peek into room %s", roomId);
                this.setState({
                    peekLoading: true,
                    isPeeking: true, // this will change to false if peeking fails
                });
                this.context.client.peekInRoom(roomId).then((room) => {
                    if (this.unmounted) {
                        return;
                    }
                    this.setState({
                        room: room,
                        peekLoading: false,
                    });
                    this.onRoomLoaded(room);
                }).catch((err) => {
                    if (this.unmounted) {
                        return;
                    }

                    // Stop peeking if anything went wrong
                    this.setState({
                        isPeeking: false,
                    });

                    // This won't necessarily be a MatrixError, but we duck-type
                    // here and say if it's got an 'errcode' key with the right value,
                    // it means we can't peek.
                    if (err.errcode === "M_GUEST_ACCESS_FORBIDDEN" || err.errcode === 'M_FORBIDDEN') {
                        // This is fine: the room just isn't peekable (we assume).
                        this.setState({
                            peekLoading: false,
                        });
                    } else {
                        throw err;
                    }
                });
            } else if (room) {
                // Stop peeking because we have joined this room previously
                this.context.client.stopPeeking();
                this.setState({ isPeeking: false });
            }
        }
    }

    private shouldShowApps(room: Room) {
        if (!BROWSER_SUPPORTS_SANDBOX || !room) return false;

        // Check if user has previously chosen to hide the app drawer for this
        // room. If so, do not show apps
        const hideWidgetKey = room.roomId + "_hide_widget_drawer";
        const hideWidgetDrawer = localStorage.getItem(hideWidgetKey);

        // If unset show the Tray
        // Otherwise (in case the user set hideWidgetDrawer by clicking the button) follow the parameter.
        const isManuallyShown = hideWidgetDrawer ? hideWidgetDrawer === "false": true;

        const widgets = this.context.widgetLayoutStore.getContainerWidgets(room, Container.Top);
        return isManuallyShown && widgets.length > 0;
    }

    componentDidMount() {
        this.onRoomViewStoreUpdate(true);

        const call = this.getCallForRoom();
        const callState = call ? call.state : null;
        this.setState({
            callState: callState,
        });

        this.context.legacyCallHandler.on(LegacyCallHandlerEvent.CallState, this.onCallState);
        window.addEventListener('beforeunload', this.onPageUnload);
    }

    shouldComponentUpdate(nextProps, nextState) {
        const hasPropsDiff = objectHasDiff(this.props, nextProps);

        const { upgradeRecommendation, ...state } = this.state;
        const { upgradeRecommendation: newUpgradeRecommendation, ...newState } = nextState;

        const hasStateDiff =
            newUpgradeRecommendation?.needsUpgrade !== upgradeRecommendation?.needsUpgrade ||
            objectHasDiff(state, newState);

        return hasPropsDiff || hasStateDiff;
    }

    componentDidUpdate() {
        // Note: We check the ref here with a flag because componentDidMount, despite
        // documentation, does not define our messagePanel ref. It looks like our spinner
        // in render() prevents the ref from being set on first mount, so we try and
        // catch the messagePanel when it does mount. Because we only want the ref once,
        // we use a boolean flag to avoid duplicate work.
        if (this.messagePanel && this.state.atEndOfLiveTimeline === undefined) {
            this.setState({
                atEndOfLiveTimeline: this.messagePanel.isAtEndOfLiveTimeline(),
            });
        }
    }

    componentWillUnmount() {
        // set a boolean to say we've been unmounted, which any pending
        // promises can use to throw away their results.
        //
        // (We could use isMounted, but facebook have deprecated that.)
        this.unmounted = true;

        this.context.legacyCallHandler.removeListener(LegacyCallHandlerEvent.CallState, this.onCallState);

        // update the scroll map before we get unmounted
        if (this.state.roomId) {
            RoomScrollStateStore.setScrollState(this.state.roomId, this.getScrollState());
        }

        if (this.state.shouldPeek) {
            this.context.client.stopPeeking();
        }

        // stop tracking room changes to format permalinks
        this.stopAllPermalinkCreators();

        dis.unregister(this.dispatcherRef);
        if (this.context.client) {
            this.context.client.removeListener(ClientEvent.Room, this.onRoom);
            this.context.client.removeListener(RoomEvent.Timeline, this.onRoomTimeline);
            this.context.client.removeListener(RoomEvent.TimelineReset, this.onRoomTimelineReset);
            this.context.client.removeListener(RoomEvent.Name, this.onRoomName);
            this.context.client.removeListener(RoomStateEvent.Events, this.onRoomStateEvents);
            this.context.client.removeListener(RoomEvent.MyMembership, this.onMyMembership);
            this.context.client.removeListener(RoomStateEvent.Update, this.onRoomStateUpdate);
            this.context.client.removeListener(CryptoEvent.KeyBackupStatus, this.onKeyBackupStatus);
            this.context.client.removeListener(CryptoEvent.DeviceVerificationChanged, this.onDeviceVerificationChanged);
            this.context.client.removeListener(CryptoEvent.UserTrustStatusChanged, this.onUserVerificationChanged);
            this.context.client.removeListener(CryptoEvent.KeysChanged, this.onCrossSigningKeysChanged);
            this.context.client.removeListener(MatrixEventEvent.Decrypted, this.onEventDecrypted);
        }

        window.removeEventListener('beforeunload', this.onPageUnload);

        this.context.roomViewStore.off(UPDATE_EVENT, this.onRoomViewStoreUpdate);

        this.context.rightPanelStore.off(UPDATE_EVENT, this.onRightPanelStoreUpdate);
        WidgetEchoStore.removeListener(UPDATE_EVENT, this.onWidgetEchoStoreUpdate);
        this.context.widgetStore.removeListener(UPDATE_EVENT, this.onWidgetStoreUpdate);

        this.props.resizeNotifier.off("isResizing", this.onIsResizing);

        if (this.state.room) {
            this.context.widgetLayoutStore.off(
                WidgetLayoutStore.emissionForRoom(this.state.room),
                this.onWidgetLayoutChange,
            );
        }

        CallStore.instance.off(CallStoreEvent.ActiveCalls, this.onActiveCalls);
        this.context.legacyCallHandler.off(LegacyCallHandlerEvent.CallState, this.onCallState);

        // cancel any pending calls to the throttled updated
        this.updateRoomMembers.cancel();

        for (const watcher of this.settingWatchers) {
            SettingsStore.unwatchSetting(watcher);
        }

        if (this.viewsLocalRoom) {
            // clean up if this was a local room
            this.context.client.store.removeRoom(this.state.room.roomId);
        }
    }

    private onRightPanelStoreUpdate = () => {
        this.setState({
            showRightPanel: this.context.rightPanelStore.isOpenForRoom(this.state.roomId),
        });
    };

    private onPageUnload = event => {
        if (ContentMessages.sharedInstance().getCurrentUploads().length > 0) {
            return event.returnValue =
                _t("You seem to be uploading files, are you sure you want to quit?");
        } else if (this.getCallForRoom() && this.state.callState !== 'ended') {
            return event.returnValue =
                _t("You seem to be in a call, are you sure you want to quit?");
        }
    };

    private onReactKeyDown = ev => {
        let handled = false;

        const action = getKeyBindingsManager().getRoomAction(ev);
        switch (action) {
            case KeyBindingAction.DismissReadMarker:
                this.messagePanel.forgetReadMarker();
                this.jumpToLiveTimeline();
                handled = true;
                break;
            case KeyBindingAction.JumpToOldestUnread:
                this.jumpToReadMarker();
                handled = true;
                break;
            case KeyBindingAction.UploadFile: {
                dis.dispatch({
                    action: "upload_file",
                    context: TimelineRenderingType.Room,
                }, true);
                handled = true;
                break;
            }
        }

        if (handled) {
            ev.stopPropagation();
            ev.preventDefault();
        }
    };

    private onCallState = (roomId: string): void => {
        // don't filter out payloads for room IDs other than props.room because
        // we may be interested in the conf 1:1 room

        if (!roomId) return;
        const call = this.getCallForRoom();
        this.setState({ callState: call ? call.state : null });
    };

    private onAction = async (payload: ActionPayload): Promise<void> => {
        switch (payload.action) {
            case 'message_sent':
                this.checkDesktopNotifications();
                break;
            case 'post_sticker_message':
                this.injectSticker(
                    payload.data.content.url,
                    payload.data.content.info,
                    payload.data.description || payload.data.name,
                    payload.data.threadId);
                break;
            case 'picture_snapshot':
                ContentMessages.sharedInstance().sendContentListToRoom(
                    [payload.file], this.state.room.roomId, null, this.context.client);
                break;
            case 'notifier_enabled':
            case Action.UploadStarted:
            case Action.UploadFinished:
            case Action.UploadCanceled:
                this.forceUpdate();
                break;
            case 'appsDrawer':
                this.setState({
                    showApps: payload.show,
                });
                break;
            case 'reply_to_event':
                if (!this.unmounted &&
                    this.state.searchResults &&
                    payload.event?.getRoomId() === this.state.roomId &&
                    payload.context === TimelineRenderingType.Search
                ) {
                    this.onCancelSearchClick();
                    // we don't need to re-dispatch as RoomViewStore knows to persist with context=Search also
                }
                break;
            case 'MatrixActions.sync':
                if (!this.state.matrixClientIsReady) {
                    this.setState({
                        matrixClientIsReady: this.context.client?.isInitialSyncComplete(),
                    }, () => {
                        // send another "initial" RVS update to trigger peeking if needed
                        this.onRoomViewStoreUpdate(true);
                    });
                }
                break;
            case 'focus_search':
                this.onSearchClick();
                break;

            case 'local_room_event':
                this.onLocalRoomEvent(payload.roomId);
                break;

            case Action.EditEvent: {
                // Quit early if we're trying to edit events in wrong rendering context
                if (payload.timelineRenderingType !== this.state.timelineRenderingType) return;
                const editState = payload.event ? new EditorStateTransfer(payload.event) : null;
                this.setState({ editState }, () => {
                    if (payload.event) {
                        this.messagePanel?.scrollToEventIfNeeded(payload.event.getId());
                    }
                });
                break;
            }

            case Action.ComposerInsert: {
                if (payload.composerType) break;

                let timelineRenderingType: TimelineRenderingType = payload.timelineRenderingType;
                // ThreadView handles Action.ComposerInsert itself due to it having its own editState
                if (timelineRenderingType === TimelineRenderingType.Thread) break;
                if (this.state.timelineRenderingType === TimelineRenderingType.Search &&
                    payload.timelineRenderingType === TimelineRenderingType.Search
                ) {
                    // we don't have the composer rendered in this state, so bring it back first
                    await this.onCancelSearchClick();
                    timelineRenderingType = TimelineRenderingType.Room;
                }

                // re-dispatch to the correct composer
                dis.dispatch<ComposerInsertPayload>({
                    ...(payload as ComposerInsertPayload),
                    timelineRenderingType,
                    composerType: this.state.editState ? ComposerType.Edit : ComposerType.Send,
                });
                break;
            }

            case Action.FocusAComposer: {
                dis.dispatch<FocusComposerPayload>({
                    ...(payload as FocusComposerPayload),
                    // re-dispatch to the correct composer
                    action: this.state.editState ? Action.FocusEditMessageComposer : Action.FocusSendMessageComposer,
                });
                break;
            }

            case "scroll_to_bottom":
                if (payload.timelineRenderingType === TimelineRenderingType.Room) {
                    this.messagePanel?.jumpToLiveTimeline();
                }
                break;
        }
    };

    private onLocalRoomEvent(roomId: string) {
        if (roomId !== this.state.room.roomId) return;
        createRoomFromLocalRoom(this.context.client, this.state.room as LocalRoom);
    }

    private onRoomTimeline = (ev: MatrixEvent, room: Room | null, toStartOfTimeline: boolean, removed, data) => {
        if (this.unmounted) return;

        // ignore events for other rooms or the notification timeline set
        if (!room || room.roomId !== this.state.room?.roomId) return;

        // ignore events from filtered timelines
        if (data.timeline.getTimelineSet() !== room.getUnfilteredTimelineSet()) return;

        if (ev.getType() === "org.matrix.room.preview_urls") {
            this.updatePreviewUrlVisibility(room);
        }

        if (ev.getType() === "m.room.encryption") {
            this.updateE2EStatus(room);
            this.updatePreviewUrlVisibility(room);
        }

        // ignore anything but real-time updates at the end of the room:
        // updates from pagination will happen when the paginate completes.
        if (toStartOfTimeline || !data || !data.liveEvent) return;

        // no point handling anything while we're waiting for the join to finish:
        // we'll only be showing a spinner.
        if (this.state.joining) return;

        if (!ev.isBeingDecrypted() && !ev.isDecryptionFailure()) {
            this.handleEffects(ev);
        }

        if (ev.getSender() !== this.context.client.credentials.userId) {
            // update unread count when scrolled up
            if (!this.state.searchResults && this.state.atEndOfLiveTimeline) {
                // no change
            } else if (!shouldHideEvent(ev, this.state)) {
                this.setState((state, props) => {
                    return { numUnreadMessages: state.numUnreadMessages + 1 };
                });
            }
        }
    };

    private onEventDecrypted = (ev: MatrixEvent) => {
        if (!this.state.room || !this.state.matrixClientIsReady) return; // not ready at all
        if (ev.getRoomId() !== this.state.room.roomId) return; // not for us
        if (ev.isDecryptionFailure()) return;
        this.handleEffects(ev);
    };

    private handleEffects = (ev: MatrixEvent) => {
        const notifState = this.context.roomNotificationStateStore.getRoomState(this.state.room);
        if (!notifState.isUnread) return;

        CHAT_EFFECTS.forEach(effect => {
            if (containsEmoji(ev.getContent(), effect.emojis) || ev.getContent().msgtype === effect.msgType) {
                // For initial threads launch, chat effects are disabled see #19731
                if (!SettingsStore.getValue("feature_thread") || !ev.isRelation(THREAD_RELATION_TYPE.name)) {
                    dis.dispatch({ action: `effects.${effect.command}` });
                }
            }
        });
    };

    private onRoomName = (room: Room) => {
        if (this.state.room && room.roomId == this.state.room.roomId) {
            this.forceUpdate();
        }
    };

    private onKeyBackupStatus = () => {
        // Key backup status changes affect whether the in-room recovery
        // reminder is displayed.
        this.forceUpdate();
    };

    public canResetTimeline = () => {
        if (!this.messagePanel) {
            return true;
        }
        return this.messagePanel.canResetTimeline();
    };

    // called when state.room is first initialised (either at initial load,
    // after a successful peek, or after we join the room).
    private onRoomLoaded = (room: Room) => {
        if (this.unmounted) return;
        // Attach a widget store listener only when we get a room
        this.context.widgetLayoutStore.on(WidgetLayoutStore.emissionForRoom(room), this.onWidgetLayoutChange);

        this.calculatePeekRules(room);
        this.updatePreviewUrlVisibility(room);
        this.loadMembersIfJoined(room);
        this.calculateRecommendedVersion(room);
        this.updateE2EStatus(room);
        this.updatePermissions(room);
        this.checkWidgets(room);

        if (
            this.getMainSplitContentType(room) !== MainSplitContentType.Timeline
            && this.context.roomNotificationStateStore.getRoomState(room).isUnread
        ) {
            // Automatically open the chat panel to make unread messages easier to discover
            this.context.rightPanelStore.setCard({ phase: RightPanelPhases.Timeline }, true, room.roomId);
        }

        this.setState({
            tombstone: this.getRoomTombstone(room),
            liveTimeline: room.getLiveTimeline(),
        });
    };

    private onRoomTimelineReset = (room: Room, timelineSet: EventTimelineSet) => {
        if (!room || room.roomId !== this.state.room?.roomId) return;
        logger.log(`Live timeline of ${room.roomId} was reset`);
        this.setState({ liveTimeline: timelineSet.getLiveTimeline() });
    };

    private getRoomTombstone(room = this.state.room) {
        return room?.currentState.getStateEvents(EventType.RoomTombstone, "");
    }

    private async calculateRecommendedVersion(room: Room) {
        const upgradeRecommendation = await room.getRecommendedVersion();
        if (this.unmounted) return;
        this.setState({ upgradeRecommendation });
    }

    private async loadMembersIfJoined(room: Room) {
        // lazy load members if enabled
        if (this.context.client.hasLazyLoadMembersEnabled()) {
            if (room && room.getMyMembership() === 'join') {
                try {
                    await room.loadMembersIfNeeded();
                    if (!this.unmounted) {
                        this.setState({ membersLoaded: true });
                    }
                } catch (err) {
                    const errorMessage = `Fetching room members for ${room.roomId} failed.` +
                        " Room members will appear incomplete.";
                    logger.error(errorMessage);
                    logger.error(err);
                }
            }
        }
    }

    private calculatePeekRules(room: Room) {
        const historyVisibility = room.currentState.getStateEvents(EventType.RoomHistoryVisibility, "");
        this.setState({
            canPeek: historyVisibility?.getContent().history_visibility === HistoryVisibility.WorldReadable,
        });
    }

    private updatePreviewUrlVisibility({ roomId }: Room) {
        // URL Previews in E2EE rooms can be a privacy leak so use a different setting which is per-room explicit
        const key = this.context.client.isRoomEncrypted(roomId) ? 'urlPreviewsEnabled_e2ee' : 'urlPreviewsEnabled';
        this.setState({
            showUrlPreview: SettingsStore.getValue(key, roomId),
        });
    }

    private onRoom = (room: Room) => {
        if (!room || room.roomId !== this.state.roomId) {
            return;
        }

        // Detach the listener if the room is changing for some reason
        if (this.state.room) {
            this.context.widgetLayoutStore.off(
                WidgetLayoutStore.emissionForRoom(this.state.room),
                this.onWidgetLayoutChange,
            );
        }

        this.setState({
            room: room,
        }, () => {
            this.onRoomLoaded(room);
        });
    };

    private onDeviceVerificationChanged = (userId: string) => {
        const room = this.state.room;
        if (!room.currentState.getMember(userId)) {
            return;
        }
        this.updateE2EStatus(room);
    };

    private onUserVerificationChanged = (userId: string) => {
        const room = this.state.room;
        if (!room || !room.currentState.getMember(userId)) {
            return;
        }
        this.updateE2EStatus(room);
    };

    private onCrossSigningKeysChanged = () => {
        const room = this.state.room;
        if (room) {
            this.updateE2EStatus(room);
        }
    };

    private async updateE2EStatus(room: Room) {
        if (!this.context.client.isRoomEncrypted(room.roomId)) return;

        // If crypto is not currently enabled, we aren't tracking devices at all,
        // so we don't know what the answer is. Let's error on the safe side and show
        // a warning for this case.
        let e2eStatus = E2EStatus.Warning;
        if (this.context.client.isCryptoEnabled()) {
            /* At this point, the user has encryption on and cross-signing on */
            e2eStatus = await shieldStatusForRoom(this.context.client, room);
        }

        if (this.unmounted) return;
        this.setState({ e2eStatus });
    }

    private onUrlPreviewsEnabledChange = () => {
        if (this.state.room) {
            this.updatePreviewUrlVisibility(this.state.room);
        }
    };

    private onRoomStateEvents = (ev: MatrixEvent, state: RoomState) => {
        // ignore if we don't have a room yet
        if (!this.state.room || this.state.room.roomId !== state.roomId) return;

        switch (ev.getType()) {
            case EventType.RoomTombstone:
                this.setState({ tombstone: this.getRoomTombstone() });
                break;

            default:
                this.updatePermissions(this.state.room);
        }
    };

    private onRoomStateUpdate = (state: RoomState) => {
        // ignore members in other rooms
        if (state.roomId !== this.state.room?.roomId) {
            return;
        }

        this.updateRoomMembers();
    };

    private onMyMembership = (room: Room, membership: string, oldMembership: string) => {
        if (room.roomId === this.state.roomId) {
            this.forceUpdate();
            this.loadMembersIfJoined(room);
            this.updatePermissions(room);
        }
    };

    private updatePermissions(room: Room) {
        if (room) {
            const me = this.context.client.getUserId();
            const canReact = (
                room.getMyMembership() === "join" &&
                room.currentState.maySendEvent(EventType.Reaction, me)
            );
            const canSendMessages = room.maySendMessage();
            const canSelfRedact = room.currentState.maySendEvent(EventType.RoomRedaction, me);

            this.setState({
                canReact,
                canSendMessages,
                canSelfRedact,
            });
        }
    }

    // rate limited because a power level change will emit an event for every member in the room.
    private updateRoomMembers = throttle(() => {
        this.updateDMState();
        this.updateE2EStatus(this.state.room);
    }, 500, { leading: true, trailing: true });

    private checkDesktopNotifications() {
        const memberCount = this.state.room.getJoinedMemberCount() + this.state.room.getInvitedMemberCount();
        // if they are not alone prompt the user about notifications so they don't miss replies
        if (memberCount > 1 && Notifier.shouldShowPrompt()) {
            showNotificationsToast(true);
        }
    }

    private updateDMState() {
        const room = this.state.room;
        if (room.getMyMembership() != "join") {
            return;
        }
        const dmInviter = room.getDMInviter();
        if (dmInviter) {
            Rooms.setDMRoom(room.roomId, dmInviter);
        }
    }

    private onSearchResultsFillRequest = (backwards: boolean): Promise<boolean> => {
        if (!backwards) {
            return Promise.resolve(false);
        }

        if (this.state.searchResults.next_batch) {
            debuglog("requesting more search results");
            const searchPromise = searchPagination(this.state.searchResults as ISearchResults);
            return this.handleSearchResult(searchPromise);
        } else {
            debuglog("no more search results");
            return Promise.resolve(false);
        }
    };

    private onInviteClick = () => {
        // open the room inviter
        dis.dispatch({
            action: 'view_invite',
            roomId: this.state.room.roomId,
        });
    };

    private onJoinButtonClicked = () => {
        // If the user is a ROU, allow them to transition to a PWLU
        if (this.context.client?.isGuest()) {
            // Join this room once the user has registered and logged in
            // (If we failed to peek, we may not have a valid room object.)
            dis.dispatch<DoAfterSyncPreparedPayload<ViewRoomPayload>>({
                action: Action.DoAfterSyncPrepared,
                deferred_action: {
                    action: Action.ViewRoom,
                    room_id: this.getRoomId(),
                    metricsTrigger: undefined,
                },
            });
            dis.dispatch({ action: 'require_registration' });
        } else {
            Promise.resolve().then(() => {
                const signUrl = this.props.threepidInvite?.signUrl;
                dis.dispatch<JoinRoomPayload>({
                    action: Action.JoinRoom,
                    roomId: this.getRoomId(),
                    opts: { inviteSignUrl: signUrl },
                    metricsTrigger: this.state.room?.getMyMembership() === "invite" ? "Invite" : "RoomPreview",
                });
                return Promise.resolve();
            });
        }
    };

    private onMessageListScroll = ev => {
        if (this.messagePanel.isAtEndOfLiveTimeline()) {
            this.setState({
                numUnreadMessages: 0,
                atEndOfLiveTimeline: true,
            });
        } else {
            this.setState({
                atEndOfLiveTimeline: false,
            });
        }
        this.updateTopUnreadMessagesBar();
    };

    private resetJumpToEvent = (eventId?: string) => {
        if (this.state.initialEventId && this.state.initialEventScrollIntoView &&
            this.state.initialEventId === eventId) {
            debuglog("Removing scroll_into_view flag from initial event");
            dis.dispatch<ViewRoomPayload>({
                action: Action.ViewRoom,
                room_id: this.state.room.roomId,
                event_id: this.state.initialEventId,
                highlighted: this.state.isInitialEventHighlighted,
                scroll_into_view: false,
                replyingToEvent: this.state.replyToEvent,
                metricsTrigger: undefined, // room doesn't change
            });
        }
    };

    private injectSticker(url: string, info: object, text: string, threadId: string | null) {
        if (this.context.client.isGuest()) {
            dis.dispatch({ action: 'require_registration' });
            return;
        }

        ContentMessages.sharedInstance()
            .sendStickerContentToRoom(url, this.state.room.roomId, threadId, info, text, this.context.client)
            .then(undefined, (error) => {
                if (error.name === "UnknownDeviceError") {
                    // Let the staus bar handle this
                    return;
                }
            });
    }

    private onSearch = (term: string, scope: SearchScope) => {
        this.setState({
            searchTerm: term,
            searchScope: scope,
            searchResults: {},
            searchHighlights: [],
        });

        // if we already have a search panel, we need to tell it to forget
        // about its scroll state.
        if (this.searchResultsPanel.current) {
            this.searchResultsPanel.current.resetScrollState();
        }

        // make sure that we don't end up showing results from
        // an aborted search by keeping a unique id.
        //
        // todo: should cancel any previous search requests.
        this.searchId = new Date().getTime();

        let roomId;
        if (scope === SearchScope.Room) roomId = this.state.room.roomId;

        debuglog("sending search request");
        const searchPromise = eventSearch(term, roomId);
        this.handleSearchResult(searchPromise);
    };

    private handleSearchResult(searchPromise: Promise<ISearchResults>): Promise<boolean> {
        // keep a record of the current search id, so that if the search terms
        // change before we get a response, we can ignore the results.
        const localSearchId = this.searchId;

        this.setState({
            searchInProgress: true,
        });

        return searchPromise.then(async (results) => {
            debuglog("search complete");
            if (this.unmounted ||
                this.state.timelineRenderingType !== TimelineRenderingType.Search ||
                this.searchId != localSearchId
            ) {
                logger.error("Discarding stale search results");
                return false;
            }

            // postgres on synapse returns us precise details of the strings
            // which actually got matched for highlighting.
            //
            // In either case, we want to highlight the literal search term
            // whether it was used by the search engine or not.

            let highlights = results.highlights;
            if (highlights.indexOf(this.state.searchTerm) < 0) {
                highlights = highlights.concat(this.state.searchTerm);
            }

            // For overlapping highlights,
            // favour longer (more specific) terms first
            highlights = highlights.sort(function(a, b) {
                return b.length - a.length;
            });

            if (this.context.client.supportsExperimentalThreads()) {
                // Process all thread roots returned in this batch of search results
                // XXX: This won't work for results coming from Seshat which won't include the bundled relationship
                for (const result of results.results) {
                    for (const event of result.context.getTimeline()) {
                        const bundledRelationship = event
                            .getServerAggregatedRelation<IThreadBundledRelationship>(THREAD_RELATION_TYPE.name);
                        if (!bundledRelationship || event.getThread()) continue;
                        const room = this.context.client.getRoom(event.getRoomId());
                        const thread = room.findThreadForEvent(event);
                        if (thread) {
                            event.setThread(thread);
                        } else {
                            room.createThread(event.getId(), event, [], true);
                        }
                    }
                }
            }

            this.setState({
                searchHighlights: highlights,
                searchResults: results,
            });
        }, (error) => {
            logger.error("Search failed", error);
            Modal.createDialog(ErrorDialog, {
                title: _t("Search failed"),
                description: ((error && error.message) ? error.message :
                    _t("Server may be unavailable, overloaded, or search timed out :(")),
            });
            return false;
        }).finally(() => {
            this.setState({
                searchInProgress: false,
            });
        });
    }

    private getSearchResultTiles() {
        // XXX: todo: merge overlapping results somehow?
        // XXX: why doesn't searching on name work?

        const ret = [];

        if (this.state.searchInProgress) {
            ret.push(<li key="search-spinner">
                <Spinner />
            </li>);
        }

        if (!this.state.searchResults.next_batch) {
            if (!this.state.searchResults?.results?.length) {
                ret.push(<li key="search-top-marker">
                    <h2 className="mx_RoomView_topMarker">{ _t("No results") }</h2>
                </li>,
                );
            } else {
                ret.push(<li key="search-top-marker">
                    <h2 className="mx_RoomView_topMarker">{ _t("No more results") }</h2>
                </li>,
                );
            }
        }

        // once dynamic content in the search results load, make the scrollPanel check
        // the scroll offsets.
        const onHeightChanged = () => {
            const scrollPanel = this.searchResultsPanel.current;
            if (scrollPanel) {
                scrollPanel.checkScroll();
            }
        };

        let lastRoomId;

        for (let i = (this.state.searchResults?.results?.length || 0) - 1; i >= 0; i--) {
            const result = this.state.searchResults.results[i];

            const mxEv = result.context.getEvent();
            const roomId = mxEv.getRoomId();
            const room = this.context.client.getRoom(roomId);
            if (!room) {
                // if we do not have the room in js-sdk stores then hide it as we cannot easily show it
                // As per the spec, an all rooms search can create this condition,
                // it happens with Seshat but not Synapse.
                // It will make the result count not match the displayed count.
                logger.log("Hiding search result from an unknown room", roomId);
                continue;
            }

            if (!haveRendererForEvent(mxEv, this.state.showHiddenEvents)) {
                // XXX: can this ever happen? It will make the result count
                // not match the displayed count.
                continue;
            }

            if (this.state.searchScope === 'All') {
                if (roomId !== lastRoomId) {
                    ret.push(<li key={mxEv.getId() + "-room"}>
                        <h2>{ _t("Room") }: { room.name }</h2>
                    </li>);
                    lastRoomId = roomId;
                }
            }

            const resultLink = "#/room/"+roomId+"/"+mxEv.getId();

            ret.push(<SearchResultTile
                key={mxEv.getId()}
                searchResult={result}
                searchHighlights={this.state.searchHighlights}
                resultLink={resultLink}
                permalinkCreator={this.permalinkCreator}
                onHeightChanged={onHeightChanged}
            />);
        }
        return ret;
    }

    private onAppsClick = () => {
        dis.dispatch({
            action: "appsDrawer",
            show: !this.state.showApps,
        });
    };

    private onForgetClick = () => {
        dis.dispatch({
            action: 'forget_room',
            room_id: this.state.room.roomId,
        });
    };

    private onRejectButtonClicked = () => {
        this.setState({
            rejecting: true,
        });
        this.context.client.leave(this.state.roomId).then(() => {
            dis.dispatch({ action: Action.ViewHomePage });
            this.setState({
                rejecting: false,
            });
        }, (error) => {
            logger.error("Failed to reject invite: %s", error);

            const msg = error.message ? error.message : JSON.stringify(error);
            Modal.createDialog(ErrorDialog, {
                title: _t("Failed to reject invite"),
                description: msg,
            });

            this.setState({
                rejecting: false,
                rejectError: error,
            });
        });
    };

    private onRejectAndIgnoreClick = async () => {
        this.setState({
            rejecting: true,
        });

        try {
            const myMember = this.state.room.getMember(this.context.client.getUserId());
            const inviteEvent = myMember.events.member;
            const ignoredUsers = this.context.client.getIgnoredUsers();
            ignoredUsers.push(inviteEvent.getSender()); // de-duped internally in the js-sdk
            await this.context.client.setIgnoredUsers(ignoredUsers);

            await this.context.client.leave(this.state.roomId);
            dis.dispatch({ action: Action.ViewHomePage });
            this.setState({
                rejecting: false,
            });
        } catch (error) {
            logger.error("Failed to reject invite: %s", error);

            const msg = error.message ? error.message : JSON.stringify(error);
            Modal.createDialog(ErrorDialog, {
                title: _t("Failed to reject invite"),
                description: msg,
            });

            this.setState({
                rejecting: false,
                rejectError: error,
            });
        }
    };

    private onRejectThreepidInviteButtonClicked = () => {
        // We can reject 3pid invites in the same way that we accept them,
        // using /leave rather than /join. In the short term though, we
        // just ignore them.
        // https://github.com/vector-im/vector-web/issues/1134
        dis.fire(Action.ViewRoomDirectory);
    };

    private onSearchClick = () => {
        this.setState({
            timelineRenderingType: this.state.timelineRenderingType === TimelineRenderingType.Search
                ? TimelineRenderingType.Room
                : TimelineRenderingType.Search,
        });
    };

    private onCancelSearchClick = (): Promise<void> => {
        return new Promise<void>(resolve => {
            this.setState({
                timelineRenderingType: TimelineRenderingType.Room,
                searchResults: null,
            }, resolve);
        });
    };

    // jump down to the bottom of this room, where new events are arriving
    private jumpToLiveTimeline = () => {
        if (this.state.initialEventId && this.state.isInitialEventHighlighted) {
            // If we were viewing a highlighted event, firing view_room without
            // an event will take care of both clearing the URL fragment and
            // jumping to the bottom
            dis.dispatch<ViewRoomPayload>({
                action: Action.ViewRoom,
                room_id: this.state.room.roomId,
                metricsTrigger: undefined, // room doesn't change
            });
        } else {
            // Otherwise we have to jump manually
            this.messagePanel.jumpToLiveTimeline();
            dis.fire(Action.FocusSendMessageComposer);
        }
    };

    // jump up to wherever our read marker is
    private jumpToReadMarker = () => {
        this.messagePanel.jumpToReadMarker();
    };

    // update the read marker to match the read-receipt
    private forgetReadMarker = ev => {
        ev.stopPropagation();
        this.messagePanel.forgetReadMarker();
    };

    // decide whether or not the top 'unread messages' bar should be shown
    private updateTopUnreadMessagesBar = () => {
        if (!this.messagePanel) {
            return;
        }

        const showBar = this.messagePanel.canJumpToReadMarker();
        if (this.state.showTopUnreadMessagesBar != showBar) {
            this.setState({ showTopUnreadMessagesBar: showBar });
        }
    };

    // get the current scroll position of the room, so that it can be
    // restored when we switch back to it.
    //
    private getScrollState(): ScrollState {
        const messagePanel = this.messagePanel;
        if (!messagePanel) return null;

        // if we're following the live timeline, we want to return null; that
        // means that, if we switch back, we will jump to the read-up-to mark.
        //
        // That should be more intuitive than slavishly preserving the current
        // scroll state, in the case where the room advances in the meantime
        // (particularly in the case that the user reads some stuff on another
        // device).
        //
        if (this.state.atEndOfLiveTimeline) {
            return null;
        }

        const scrollState = messagePanel.getScrollState();

        // getScrollState on TimelinePanel *may* return null, so guard against that
        if (!scrollState || scrollState.stuckAtBottom) {
            // we don't really expect to be in this state, but it will
            // occasionally happen when no scroll state has been set on the
            // messagePanel (ie, we didn't have an initial event (so it's
            // probably a new room), there has been no user-initiated scroll, and
            // no read-receipts have arrived to update the scroll position).
            //
            // Return null, which will cause us to scroll to last unread on
            // reload.
            return null;
        }

        return {
            focussedEvent: scrollState.trackedScrollToken,
            pixelOffset: scrollState.pixelOffset,
        };
    }

    private onStatusBarVisible = () => {
        if (this.unmounted || this.state.statusBarVisible) return;
        this.setState({ statusBarVisible: true });
    };

    private onStatusBarHidden = () => {
        // This is currently not desired as it is annoying if it keeps expanding and collapsing
        if (this.unmounted || !this.state.statusBarVisible) return;
        this.setState({ statusBarVisible: false });
    };

    /**
     * called by the parent component when PageUp/Down/etc is pressed.
     *
     * We pass it down to the scroll panel.
     */
    public handleScrollKey = ev => {
        let panel: ScrollPanel | TimelinePanel;
        if (this.searchResultsPanel.current) {
            panel = this.searchResultsPanel.current;
        } else if (this.messagePanel) {
            panel = this.messagePanel;
        }

        if (panel) {
            panel.handleScrollKey(ev);
        }
    };

    /**
     * get any current call for this room
     */
    private getCallForRoom(): MatrixCall {
        if (!this.state.room) {
            return null;
        }
        return this.context.legacyCallHandler.getCallForRoom(this.state.room.roomId);
    }

    // this has to be a proper method rather than an unnamed function,
    // otherwise react calls it with null on each update.
    private gatherTimelinePanelRef = r => {
        this.messagePanel = r;
    };

    private getOldRoom() {
        const createEvent = this.state.room.currentState.getStateEvents(EventType.RoomCreate, "");
        if (!createEvent || !createEvent.getContent()['predecessor']) return null;

        return this.context.client.getRoom(createEvent.getContent()['predecessor']['room_id']);
    }

    getHiddenHighlightCount() {
        const oldRoom = this.getOldRoom();
        if (!oldRoom) return 0;
        return oldRoom.getUnreadNotificationCount(NotificationCountType.Highlight);
    }

    onHiddenHighlightsClick = () => {
        const oldRoom = this.getOldRoom();
        if (!oldRoom) return;
        dis.dispatch<ViewRoomPayload>({
            action: Action.ViewRoom,
            room_id: oldRoom.roomId,
            metricsTrigger: "Predecessor",
        });
    };

    private get messagePanelClassNames(): string {
        return classNames("mx_RoomView_messagePanel", {
            mx_IRCLayout: this.state.layout === Layout.IRC,
        });
    }

    private onFileDrop = (dataTransfer: DataTransfer) => ContentMessages.sharedInstance().sendContentListToRoom(
        Array.from(dataTransfer.files),
        this.state.room?.roomId ?? this.state.roomId,
        null,
        this.context.client,
        TimelineRenderingType.Room,
    );

    private onMeasurement = (narrow: boolean): void => {
        this.setState({ narrow });
    };

    private get viewsLocalRoom(): boolean {
        return isLocalRoom(this.state.room);
    }

    private get permalinkCreator(): RoomPermalinkCreator {
        return this.getPermalinkCreatorForRoom(this.state.room);
    }

    private renderLocalRoomCreateLoader(): ReactElement {
        const names = this.state.room.getDefaultRoomName(this.context.client.getUserId());
        return <RoomContext.Provider value={this.state}>
            <LocalRoomCreateLoader
                names={names}
                resizeNotifier={this.props.resizeNotifier}
            />
        </RoomContext.Provider>;
    }

    private renderLocalRoomView(): ReactElement {
        return <RoomContext.Provider value={this.state}>
            <LocalRoomView
                resizeNotifier={this.props.resizeNotifier}
                permalinkCreator={this.permalinkCreator}
                roomView={this.roomView}
                onFileDrop={this.onFileDrop}
            />
        </RoomContext.Provider>;
    }

    render() {
        if (this.state.room instanceof LocalRoom) {
            if (this.state.room.state === LocalRoomState.CREATING) {
                return this.renderLocalRoomCreateLoader();
            }

            return this.renderLocalRoomView();
        }

        if (!this.state.room) {
            const loading = !this.state.matrixClientIsReady || this.state.roomLoading || this.state.peekLoading;
            if (loading) {
                // Assume preview loading if we don't have a ready client or a room ID (still resolving the alias)
                const previewLoading = !this.state.matrixClientIsReady || !this.state.roomId || this.state.peekLoading;
                return (
                    <div className="mx_RoomView">
                        <ErrorBoundary>
                            <RoomPreviewBar
                                canPreview={false}
                                previewLoading={previewLoading && !this.state.roomLoadError}
                                error={this.state.roomLoadError}
                                loading={loading}
                                joining={this.state.joining}
                                oobData={this.props.oobData}
                            />
                        </ErrorBoundary>
                    </div>
                );
            } else {
                let inviterName = undefined;
                if (this.props.oobData) {
                    inviterName = this.props.oobData.inviterName;
                }
                const invitedEmail = this.props.threepidInvite?.toEmail;

                // We have no room object for this room, only the ID.
                // We've got to this room by following a link, possibly a third party invite.
                const roomAlias = this.state.roomAlias;
                return (
                    <div className="mx_RoomView">
                        <ErrorBoundary>
                            <RoomPreviewBar
                                onJoinClick={this.onJoinButtonClicked}
                                onForgetClick={this.onForgetClick}
                                onRejectClick={this.onRejectThreepidInviteButtonClicked}
                                canPreview={false}
                                error={this.state.roomLoadError}
                                roomAlias={roomAlias}
                                joining={this.state.joining}
                                inviterName={inviterName}
                                invitedEmail={invitedEmail}
                                oobData={this.props.oobData}
                                signUrl={this.props.threepidInvite?.signUrl}
                                room={this.state.room}
                            />
                        </ErrorBoundary>
                    </div>
                );
            }
        }

        const myMembership = this.state.room.getMyMembership();
        if (
            isVideoRoom(this.state.room)
            && !(SettingsStore.getValue("feature_video_rooms") && myMembership === "join")
        ) {
            return <ErrorBoundary>
                <div className="mx_MainSplit">
                    <RoomPreviewCard
                        room={this.state.room}
                        onJoinButtonClicked={this.onJoinButtonClicked}
                        onRejectButtonClicked={this.onRejectButtonClicked}
                    />
                </div>;
            </ErrorBoundary>;
        }

        // SpaceRoomView handles invites itself
        if (myMembership === "invite" && !this.state.room.isSpaceRoom()) {
            if (this.state.joining || this.state.rejecting) {
                return (
                    <ErrorBoundary>
                        <RoomPreviewBar
                            canPreview={false}
                            error={this.state.roomLoadError}
                            joining={this.state.joining}
                            rejecting={this.state.rejecting}
                        />
                    </ErrorBoundary>
                );
            } else {
                const myUserId = this.context.client.credentials.userId;
                const myMember = this.state.room.getMember(myUserId);
                const inviteEvent = myMember ? myMember.events.member : null;
                let inviterName = _t("Unknown");
                if (inviteEvent) {
                    inviterName = inviteEvent.sender ? inviteEvent.sender.name : inviteEvent.getSender();
                }

                // We deliberately don't try to peek into invites, even if we have permission to peek
                // as they could be a spam vector.
                // XXX: in future we could give the option of a 'Preview' button which lets them view anyway.

                // We have a regular invite for this room.
                return (
                    <div className="mx_RoomView">
                        <ErrorBoundary>
                            <RoomPreviewBar
                                onJoinClick={this.onJoinButtonClicked}
                                onForgetClick={this.onForgetClick}
                                onRejectClick={this.onRejectButtonClicked}
                                onRejectAndIgnoreClick={this.onRejectAndIgnoreClick}
                                inviterName={inviterName}
                                canPreview={false}
                                joining={this.state.joining}
                                room={this.state.room}
                            />
                        </ErrorBoundary>
                    </div>
                );
            }
        }

        // We have successfully loaded this room, and are not previewing.
        // Display the "normal" room view.

        let activeCall = null;
        {
            // New block because this variable doesn't need to hang around for the rest of the function
            const call = this.getCallForRoom();
            if (call && (this.state.callState !== 'ended' && this.state.callState !== 'ringing')) {
                activeCall = call;
            }
        }

        const scrollheaderClasses = classNames({
            mx_RoomView_scrollheader: true,
        });

        let statusBar;
        let isStatusAreaExpanded = true;

        if (ContentMessages.sharedInstance().getCurrentUploads().length > 0) {
            statusBar = <UploadBar room={this.state.room} />;
        } else if (!this.state.searchResults) {
            isStatusAreaExpanded = this.state.statusBarVisible;
            statusBar = <RoomStatusBar
                room={this.state.room}
                isPeeking={myMembership !== "join"}
                onInviteClick={this.onInviteClick}
                onVisible={this.onStatusBarVisible}
                onHidden={this.onStatusBarHidden}
            />;
        }

        const statusBarAreaClass = classNames("mx_RoomView_statusArea", {
            "mx_RoomView_statusArea_expanded": isStatusAreaExpanded,
        });

        // if statusBar does not exist then statusBarArea is blank and takes up unnecessary space on the screen
        // show statusBarArea only if statusBar is present
        const statusBarArea = statusBar && <div className={statusBarAreaClass}>
            <div className="mx_RoomView_statusAreaBox">
                <div className="mx_RoomView_statusAreaBox_line" />
                { statusBar }
            </div>
        </div>;

        const roomVersionRecommendation = this.state.upgradeRecommendation;
        const showRoomUpgradeBar = (
            roomVersionRecommendation &&
            roomVersionRecommendation.needsUpgrade &&
            this.state.room.userMayUpgradeRoom(this.context.client.credentials.userId)
        );

        const hiddenHighlightCount = this.getHiddenHighlightCount();

        let aux = null;
        let previewBar;
        if (this.state.timelineRenderingType === TimelineRenderingType.Search) {
            aux = <SearchBar
                searchInProgress={this.state.searchInProgress}
                onCancelClick={this.onCancelSearchClick}
                onSearch={this.onSearch}
                isRoomEncrypted={this.context.client.isRoomEncrypted(this.state.room.roomId)}
            />;
        } else if (showRoomUpgradeBar) {
            aux = <RoomUpgradeWarningBar room={this.state.room} />;
        } else if (myMembership !== "join") {
            // We do have a room object for this room, but we're not currently in it.
            // We may have a 3rd party invite to it.
            let inviterName = undefined;
            if (this.props.oobData) {
                inviterName = this.props.oobData.inviterName;
            }
            const invitedEmail = this.props.threepidInvite?.toEmail;
            previewBar = (
                <RoomPreviewBar
                    onJoinClick={this.onJoinButtonClicked}
                    onForgetClick={this.onForgetClick}
                    onRejectClick={this.onRejectThreepidInviteButtonClicked}
                    joining={this.state.joining}
                    inviterName={inviterName}
                    invitedEmail={invitedEmail}
                    oobData={this.props.oobData}
                    canPreview={this.state.canPeek}
                    room={this.state.room}
                />
            );
            if (!this.state.canPeek && !this.state.room?.isSpaceRoom()) {
                return (
                    <div className="mx_RoomView">
                        { previewBar }
                    </div>
                );
            }
        } else if (hiddenHighlightCount > 0) {
            aux = (
                <AccessibleButton
                    element="div"
                    className="mx_RoomView_auxPanel_hiddenHighlights"
                    onClick={this.onHiddenHighlightsClick}
                >
                    { _t(
                        "You have %(count)s unread notifications in a prior version of this room.",
                        { count: hiddenHighlightCount },
                    ) }
                </AccessibleButton>
            );
        }

        if (this.state.room?.isSpaceRoom() && !this.props.forceTimeline) {
            return <SpaceRoomView
                space={this.state.room}
                justCreatedOpts={this.props.justCreatedOpts}
                resizeNotifier={this.props.resizeNotifier}
                onJoinButtonClicked={this.onJoinButtonClicked}
                onRejectButtonClicked={this.props.threepidInvite
                    ? this.onRejectThreepidInviteButtonClicked
                    : this.onRejectButtonClicked}
            />;
        }

        const auxPanel = (
            <AuxPanel
                room={this.state.room}
                userId={this.context.client.credentials.userId}
                showApps={this.state.showApps}
                resizeNotifier={this.props.resizeNotifier}
            >
                { aux }
            </AuxPanel>
        );

        let messageComposer; let searchInfo;
        const showComposer = (
            // joined and not showing search results
            myMembership === 'join' && !this.state.searchResults
        );
        if (showComposer) {
            messageComposer =
                <MessageComposer
                    room={this.state.room}
                    e2eStatus={this.state.e2eStatus}
                    resizeNotifier={this.props.resizeNotifier}
                    replyToEvent={this.state.replyToEvent}
                    permalinkCreator={this.permalinkCreator}
                />;
        }

        // TODO: Why aren't we storing the term/scope/count in this format
        // in this.state if this is what RoomHeader desires?
        if (this.state.searchResults) {
            searchInfo = {
                searchTerm: this.state.searchTerm,
                searchScope: this.state.searchScope,
                searchCount: this.state.searchResults.count,
            };
        }

        // if we have search results, we keep the messagepanel (so that it preserves its
        // scroll state), but hide it.
        let searchResultsPanel;
        let hideMessagePanel = false;

        if (this.state.searchResults) {
            // show searching spinner
            if (this.state.searchResults.count === undefined) {
                searchResultsPanel = (
                    <div className="mx_RoomView_messagePanel mx_RoomView_messagePanelSearchSpinner" />
                );
            } else {
                searchResultsPanel = (
                    <ScrollPanel
                        ref={this.searchResultsPanel}
                        className={"mx_RoomView_searchResultsPanel " + this.messagePanelClassNames}
                        onFillRequest={this.onSearchResultsFillRequest}
                        resizeNotifier={this.props.resizeNotifier}
                    >
                        <li className={scrollheaderClasses} />
                        { this.getSearchResultTiles() }
                    </ScrollPanel>
                );
            }
            hideMessagePanel = true;
        }

        let highlightedEventId = null;
        if (this.state.isInitialEventHighlighted) {
            highlightedEventId = this.state.initialEventId;
        }

        const messagePanel = (
            <TimelinePanel
                ref={this.gatherTimelinePanelRef}
                timelineSet={this.state.room.getUnfilteredTimelineSet()}
                showReadReceipts={this.state.showReadReceipts}
                manageReadReceipts={!this.state.isPeeking}
                sendReadReceiptOnLoad={!this.state.wasContextSwitch}
                manageReadMarkers={!this.state.isPeeking}
                hidden={hideMessagePanel}
                highlightedEventId={highlightedEventId}
                eventId={this.state.initialEventId}
                eventScrollIntoView={this.state.initialEventScrollIntoView}
                eventPixelOffset={this.state.initialEventPixelOffset}
                onScroll={this.onMessageListScroll}
                onEventScrolledIntoView={this.resetJumpToEvent}
                onReadMarkerUpdated={this.updateTopUnreadMessagesBar}
                showUrlPreview={this.state.showUrlPreview}
                className={this.messagePanelClassNames}
                membersLoaded={this.state.membersLoaded}
                permalinkCreator={this.permalinkCreator}
                resizeNotifier={this.props.resizeNotifier}
                showReactions={true}
                layout={this.state.layout}
                editState={this.state.editState}
            />);

        let topUnreadMessagesBar = null;
        // Do not show TopUnreadMessagesBar if we have search results showing, it makes no sense
        if (this.state.showTopUnreadMessagesBar && !this.state.searchResults) {
            topUnreadMessagesBar = (
                <TopUnreadMessagesBar onScrollUpClick={this.jumpToReadMarker} onCloseClick={this.forgetReadMarker} />
            );
        }
        let jumpToBottom;
        // Do not show JumpToBottomButton if we have search results showing, it makes no sense
        if (this.state.atEndOfLiveTimeline === false && !this.state.searchResults) {
            jumpToBottom = (<JumpToBottomButton
                highlight={this.state.room.getUnreadNotificationCount(NotificationCountType.Highlight) > 0}
                numUnreadMessages={this.state.numUnreadMessages}
                onScrollToBottomClick={this.jumpToLiveTimeline}
            />);
        }

        const showRightPanel = this.state.room && this.state.showRightPanel;

        const rightPanel = showRightPanel
            ? <RightPanel
                room={this.state.room}
                resizeNotifier={this.props.resizeNotifier}
                permalinkCreator={this.permalinkCreator}
                e2eStatus={this.state.e2eStatus} />
            : null;

        const timelineClasses = classNames("mx_RoomView_timeline", {
            mx_RoomView_timeline_rr_enabled: this.state.showReadReceipts,
        });

        const mainClasses = classNames("mx_RoomView", {
            mx_RoomView_inCall: Boolean(activeCall),
            mx_RoomView_immersive: this.state.mainSplitContentType !== MainSplitContentType.Timeline,
        });

        const showChatEffects = SettingsStore.getValue('showChatEffects');

        let mainSplitBody: React.ReactFragment;
        let mainSplitContentClassName: string;
        // Decide what to show in the main split
        switch (this.state.mainSplitContentType) {
            case MainSplitContentType.Timeline:
                mainSplitContentClassName = "mx_MainSplit_timeline";
                mainSplitBody = <>
                    <Measured
                        sensor={this.roomViewBody.current}
                        onMeasurement={this.onMeasurement}
                    />
                    { auxPanel }
                    <div className={timelineClasses}>
                        <FileDropTarget parent={this.roomView.current} onFileDrop={this.onFileDrop} />
                        { topUnreadMessagesBar }
                        { jumpToBottom }
                        { messagePanel }
                        { searchResultsPanel }
                    </div>
                    { statusBarArea }
                    { previewBar }
                    { messageComposer }
                </>;
                break;
            case MainSplitContentType.MaximisedWidget:
                mainSplitContentClassName = "mx_MainSplit_maximisedWidget";
                mainSplitBody = <>
                    <AppsDrawer
                        room={this.state.room}
                        userId={this.context.client.credentials.userId}
                        resizeNotifier={this.props.resizeNotifier}
                        showApps={true}
                    />
                    { previewBar }
                </>;
                break;
            case MainSplitContentType.Call: {
                mainSplitContentClassName = "mx_MainSplit_call";
                mainSplitBody = <>
                    <CallView
                        room={this.state.room}
                        resizing={this.state.resizing}
                        waitForCall={isVideoRoom(this.state.room)}
                    />
                    { previewBar }
                </>;
            }
        }
        const mainSplitContentClasses = classNames("mx_RoomView_body", mainSplitContentClassName);

        let excludedRightPanelPhaseButtons = [RightPanelPhases.Timeline];
        let onAppsClick = this.onAppsClick;
        let onForgetClick = this.onForgetClick;
        let onSearchClick = this.onSearchClick;
        let onInviteClick = null;
        let viewingCall = false;

        // Simplify the header for other main split types
        switch (this.state.mainSplitContentType) {
            case MainSplitContentType.MaximisedWidget:
                excludedRightPanelPhaseButtons = [
                    RightPanelPhases.ThreadPanel,
                    RightPanelPhases.PinnedMessages,
                ];
                onAppsClick = null;
                onForgetClick = null;
                onSearchClick = null;
                break;
            case MainSplitContentType.Call:
                excludedRightPanelPhaseButtons = [
                    RightPanelPhases.ThreadPanel,
                    RightPanelPhases.PinnedMessages,
                    RightPanelPhases.NotificationPanel,
                ];
                if (!isVideoRoom(this.state.room)) {
                    excludedRightPanelPhaseButtons.push(RightPanelPhases.RoomSummary);
                    if (this.state.activeCall === null) {
                        excludedRightPanelPhaseButtons.push(RightPanelPhases.Timeline);
                    }
                }
                onAppsClick = null;
                onForgetClick = null;
                onSearchClick = null;
                if (this.state.room.canInvite(this.context.client.credentials.userId)) {
                    onInviteClick = this.onInviteClick;
                }
                viewingCall = true;
        }

        return (
            <RoomContext.Provider value={this.state}>
                <main className={mainClasses} ref={this.roomView} onKeyDown={this.onReactKeyDown}>
                    { showChatEffects && this.roomView.current &&
                        <EffectsOverlay roomWidth={this.roomView.current.offsetWidth} />
                    }
                    <ErrorBoundary>
                        <RoomHeader
                            room={this.state.room}
                            searchInfo={searchInfo}
                            oobData={this.props.oobData}
                            inRoom={myMembership === 'join'}
                            onSearchClick={onSearchClick}
                            onInviteClick={onInviteClick}
                            onForgetClick={(myMembership === "leave") ? onForgetClick : null}
                            e2eStatus={this.state.e2eStatus}
                            onAppsClick={this.state.hasPinnedWidgets ? onAppsClick : null}
                            appsShown={this.state.showApps}
                            excludedRightPanelPhaseButtons={excludedRightPanelPhaseButtons}
                            showButtons={!this.viewsLocalRoom}
                            enableRoomOptionsMenu={!this.viewsLocalRoom}
                            viewingCall={viewingCall}
                            activeCall={this.state.activeCall}
                        />
                        <MainSplit panel={rightPanel} resizeNotifier={this.props.resizeNotifier}>
                            <div className={mainSplitContentClasses} ref={this.roomViewBody} data-layout={this.state.layout}>
                                { mainSplitBody }
                            </div>
                        </MainSplit>
                    </ErrorBoundary>
                </main>
            </RoomContext.Provider>
        );
    }
}

export default RoomView;