New room list: avoid extra render for room list item

src/components/viewmodels/roomlist/RoomListItemViewModel.tsx

@@ -5,7 +5,7 @@
  * Please see LICENSE files in the repository root for full details.
  */
 
-import { useCallback, useMemo } from "react";
+import { useCallback, useEffect, useMemo, useState } from "react";
 import { type Room, RoomEvent } from "matrix-js-sdk/src/matrix";
 
 import dispatcher from "../../../dispatcher/dispatcher";
@@ -16,12 +16,17 @@ import { _t } from "../../../languageHandler";
 import { type RoomNotificationState } from "../../../stores/notifications/RoomNotificationState";
 import { RoomNotificationStateStore } from "../../../stores/notifications/RoomNotificationStateStore";
 import { useMatrixClientContext } from "../../../contexts/MatrixClientContext";
-import { useEventEmitterState } from "../../../hooks/useEventEmitter";
+import { useEventEmitterState, useTypedEventEmitter } from "../../../hooks/useEventEmitter";
 import { DefaultTagID } from "../../../stores/room-list/models";
 import { useCall, useConnectionState, useParticipantCount } from "../../../hooks/useCall";
 import { type ConnectionState } from "../../../models/Call";
+import { NotificationStateEvents } from "../../../stores/notifications/NotificationState";
 
 export interface RoomListItemViewState {
+    /**
+     * The name of the room.
+     */
+    name: string;
     /**
      * Whether the hover menu should be shown.
      */
@@ -55,6 +60,10 @@ export interface RoomListItemViewState {
      * Whether there are participants in the call.
      */
     hasParticipantInCall: boolean;
+    /**
+     * Whether the notification decoration should be shown.
+     */
+    showNotificationDecoration: boolean;
 }
 
 /**
@@ -65,11 +74,23 @@ export function useRoomListItemViewModel(room: Room): RoomListItemViewState {
     const matrixClient = useMatrixClientContext();
     const roomTags = useEventEmitterState(room, RoomEvent.Tags, () => room.tags);
     const isArchived = Boolean(roomTags[DefaultTagID.Archived]);
+    const name = useEventEmitterState(room, RoomEvent.Name, () => room.name);
 
     const notificationState = useMemo(() => RoomNotificationStateStore.instance.getRoomState(room), [room]);
-    const invited = notificationState.invited;
-    const a11yLabel = getA11yLabel(room, notificationState);
-    const isBold = notificationState.hasAnyNotificationOrActivity;
+
+    const [a11yLabel, setA11yLabel] = useState(getA11yLabel(name, notificationState));
+    const [{ isBold, invited, hasVisibleNotification }, setNotificationValues] = useState(
+        getNotificationValues(notificationState),
+    );
+    useEffect(() => {
+        setA11yLabel(getA11yLabel(name, notificationState));
+    }, [name, notificationState]);
+
+    // Listen to changes in the notification state and update the values
+    useTypedEventEmitter(notificationState, NotificationStateEvents.Update, () => {
+        setA11yLabel(getA11yLabel(name, notificationState));
+        setNotificationValues(getNotificationValues(notificationState));
+    });
 
     // We don't want to show the hover menu if
     // - there is an invitation for this room
@@ -86,6 +107,8 @@ export function useRoomListItemViewModel(room: Room): RoomListItemViewState {
     const hasParticipantInCall = useParticipantCount(call) > 0;
     const callConnectionState = call ? connectionState : null;
 
+    const showNotificationDecoration = hasVisibleNotification || hasParticipantInCall;
+
     // Actions
 
     const openRoom = useCallback((): void => {
@@ -97,6 +120,7 @@ export function useRoomListItemViewModel(room: Room): RoomListItemViewState {
     }, [room]);
 
     return {
+        name,
         notificationState,
         showHoverMenu,
         openRoom,
@@ -105,34 +129,59 @@ export function useRoomListItemViewModel(room: Room): RoomListItemViewState {
         isVideoRoom,
         callConnectionState,
         hasParticipantInCall,
+        showNotificationDecoration,
+    };
+}
+
+/**
+ * Calculate the values from the notification state
+ * @param notificationState
+ */
+function getNotificationValues(notificationState: RoomNotificationState): {
+    computeA11yLabel: (name: string) => string;
+    isBold: boolean;
+    invited: boolean;
+    hasVisibleNotification: boolean;
+} {
+    const invited = notificationState.invited;
+    const computeA11yLabel = (name: string): string => getA11yLabel(name, notificationState);
+    const isBold = notificationState.hasAnyNotificationOrActivity;
+
+    const hasVisibleNotification = notificationState.hasAnyNotificationOrActivity || notificationState.muted;
+
+    return {
+        computeA11yLabel,
+        isBold,
+        invited,
+        hasVisibleNotification,
     };
 }
 
 /**
  * Get the a11y label for the room list item
- * @param room
+ * @param roomName
  * @param notificationState
  */
-function getA11yLabel(room: Room, notificationState: RoomNotificationState): string {
-    if (notificationState.isUnsetMessage) {
+function getA11yLabel(roomName: string, notificationState: RoomNotificationState): string {
+    if (notificationState.isUnsentMessage) {
         return _t("a11y|room_messsage_not_sent", {
-            roomName: room.name,
+            roomName,
         });
     } else if (notificationState.invited) {
         return _t("a11y|room_n_unread_invite", {
-            roomName: room.name,
+            roomName,
         });
     } else if (notificationState.isMention) {
         return _t("a11y|room_n_unread_messages_mentions", {
-            roomName: room.name,
+            roomName,
             count: notificationState.count,
         });
     } else if (notificationState.hasUnreadCount) {
         return _t("a11y|room_n_unread_messages", {
-            roomName: room.name,
+            roomName,
             count: notificationState.count,
         });
     } else {
-        return _t("room_list|room|open_room", { roomName: room.name });
+        return _t("room_list|room|open_room", { roomName });
     }
 }

src/components/views/rooms/NotificationDecoration.tsx

@@ -15,6 +15,8 @@ import { UnreadCounter, Unread } from "@vector-im/compound-web";
 
 import { Flex } from "../../utils/Flex";
 import { type RoomNotificationState } from "../../../stores/notifications/RoomNotificationState";
+import { useTypedEventEmitterState } from "../../../hooks/useEventEmitter";
+import { NotificationStateEvents } from "../../../stores/notifications/NotificationState";
 
 interface NotificationDecorationProps extends HTMLProps<HTMLDivElement> {
     /**
@@ -35,16 +37,27 @@ export function NotificationDecoration({
     hasVideoCall,
     ...props
 }: NotificationDecorationProps): JSX.Element | null {
+    // Listen to the notification state and update the component when it changes
     const {
         hasAnyNotificationOrActivity,
-        isUnsetMessage,
+        isUnsentMessage,
         invited,
         isMention,
         isActivityNotification,
         isNotification,
         count,
         muted,
-    } = notificationState;
+    } = useTypedEventEmitterState(notificationState, NotificationStateEvents.Update, () => ({
+        hasAnyNotificationOrActivity: notificationState.hasAnyNotificationOrActivity,
+        isUnsentMessage: notificationState.isUnsentMessage,
+        invited: notificationState.invited,
+        isMention: notificationState.isMention,
+        isActivityNotification: notificationState.isActivityNotification,
+        isNotification: notificationState.isNotification,
+        count: notificationState.count,
+        muted: notificationState.muted,
+    }));
+
     if (!hasAnyNotificationOrActivity && !muted && !hasVideoCall) return null;
 
     return (
@@ -55,7 +68,7 @@ export function NotificationDecoration({
             {...props}
             data-testid="notification-decoration"
         >
-            {isUnsetMessage && <ErrorIcon width="20px" height="20px" fill="var(--cpd-color-icon-critical-primary)" />}
+            {isUnsentMessage && <ErrorIcon width="20px" height="20px" fill="var(--cpd-color-icon-critical-primary)" />}
             {hasVideoCall && <VideoCallIcon width="20px" height="20px" fill="var(--cpd-color-icon-accent-primary)" />}
             {invited && <EmailIcon width="20px" height="20px" fill="var(--cpd-color-icon-accent-primary)" />}
             {isMention && <MentionIcon width="20px" height="20px" fill="var(--cpd-color-icon-accent-primary)" />}

src/components/views/rooms/RoomListPanel/RoomListItemView.tsx

@@ -5,7 +5,7 @@
  * Please see LICENSE files in the repository root for full details.
  */
 
-import React, { type JSX, useState } from "react";
+import React, { type JSX, memo, useState } from "react";
 import { type Room } from "matrix-js-sdk/src/matrix";
 import classNames from "classnames";
 
@@ -29,7 +29,11 @@ interface RoomListItemViewPropsProps extends React.HTMLAttributes<HTMLButtonElem
 /**
  * An item in the room list
  */
-export function RoomListItemView({ room, isSelected, ...props }: RoomListItemViewPropsProps): JSX.Element {
+export const RoomListItemView = memo(function RoomListItemView({
+    room,
+    isSelected,
+    ...props
+}: RoomListItemViewPropsProps): JSX.Element {
     const vm = useRoomListItemViewModel(room);
 
     const [isHover, setIsHover] = useState(false);
@@ -38,9 +42,7 @@ export function RoomListItemView({ room, isSelected, ...props }: RoomListItemVie
     // Using display: none; and then display:flex when hovered in CSS causes the menu to be misaligned
     const showHoverDecoration = (isMenuOpen || isHover) && vm.showHoverMenu;
 
-    const isNotificationDecorationVisible =
-        !showHoverDecoration &&
-        (vm.notificationState.hasAnyNotificationOrActivity || vm.notificationState.muted || vm.hasParticipantInCall);
+    const isNotificationDecorationVisible = !showHoverDecoration && vm.showNotificationDecoration;
 
     return (
         <button
@@ -71,8 +73,8 @@ export function RoomListItemView({ room, isSelected, ...props }: RoomListItemVie
                     justify="space-between"
                 >
                     {/* We truncate the room name when too long. Title here is to show the full name on hover */}
-                    <span className="mx_RoomListItemView_roomName" title={room.name}>
-                        {room.name}
+                    <span className="mx_RoomListItemView_roomName" title={vm.name}>
+                        {vm.name}
                     </span>
                     {showHoverDecoration ? (
                         <RoomListItemMenuView
@@ -86,15 +88,17 @@ export function RoomListItemView({ room, isSelected, ...props }: RoomListItemVie
                     ) : (
                         <>
                             {/* aria-hidden because we summarise the unread count/notification status in a11yLabel variable */}
-                            <NotificationDecoration
-                                notificationState={vm.notificationState}
-                                aria-hidden={true}
-                                hasVideoCall={vm.hasParticipantInCall}
-                            />
+                            {vm.showNotificationDecoration && (
+                                <NotificationDecoration
+                                    notificationState={vm.notificationState}
+                                    aria-hidden={true}
+                                    hasVideoCall={vm.hasParticipantInCall}
+                                />
+                            )}
                         </>
                     )}
                 </Flex>
             </Flex>
         </button>
     );
-}
+});

src/stores/notifications/RoomNotificationState.ts

@@ -62,9 +62,9 @@ export class RoomNotificationState extends NotificationState implements IDestroy
     }
 
     /**
-     * True if the notification is an unset message.
+     * True if the notification is an unsent message.
      */
-    public get isUnsetMessage(): boolean {
+    public get isUnsentMessage(): boolean {
         return this.level === NotificationLevel.Unsent;
     }
 

test/unit-tests/components/viewmodels/roomlist/RoomListItemViewModel-test.tsx

@@ -19,6 +19,7 @@ import {
 } from "../../../../../src/components/viewmodels/roomlist/utils";
 import { RoomNotificationState } from "../../../../../src/stores/notifications/RoomNotificationState";
 import { RoomNotificationStateStore } from "../../../../../src/stores/notifications/RoomNotificationStateStore";
+import * as UseCallModule from "../../../../../src/hooks/useCall";
 
 jest.mock("../../../../../src/components/viewmodels/roomlist/utils", () => ({
     hasAccessToOptionsMenu: jest.fn().mockReturnValue(false),
@@ -86,6 +87,49 @@ describe("RoomListItemViewModel", () => {
         expect(vm.current.showHoverMenu).toBe(true);
     });
 
+    describe("notification", () => {
+        let notificationState: RoomNotificationState;
+        beforeEach(() => {
+            notificationState = new RoomNotificationState(room, false);
+            jest.spyOn(RoomNotificationStateStore.instance, "getRoomState").mockReturnValue(notificationState);
+        });
+
+        it("should show notification decoration if there is call has participant", () => {
+            jest.spyOn(UseCallModule, "useParticipantCount").mockReturnValue(1);
+
+            const { result: vm } = renderHook(
+                () => useRoomListItemViewModel(room),
+                withClientContextRenderOptions(room.client),
+            );
+            expect(vm.current.showNotificationDecoration).toBe(true);
+        });
+
+        it.each([
+            {
+                label: "hasAnyNotificationOrActivity",
+                mock: () => jest.spyOn(notificationState, "hasAnyNotificationOrActivity", "get").mockReturnValue(true),
+            },
+            { label: "muted", mock: () => jest.spyOn(notificationState, "muted", "get").mockReturnValue(true) },
+        ])("should show notification decoration if $label=true", ({ mock }) => {
+            mock();
+            const { result: vm } = renderHook(
+                () => useRoomListItemViewModel(room),
+                withClientContextRenderOptions(room.client),
+            );
+            expect(vm.current.showNotificationDecoration).toBe(true);
+        });
+
+        it("should be bold if there is a notification", () => {
+            jest.spyOn(notificationState, "hasAnyNotificationOrActivity", "get").mockReturnValue(true);
+
+            const { result: vm } = renderHook(
+                () => useRoomListItemViewModel(room),
+                withClientContextRenderOptions(room.client),
+            );
+            expect(vm.current.isBold).toBe(true);
+        });
+    });
+
     describe("a11yLabel", () => {
         let notificationState: RoomNotificationState;
         beforeEach(() => {
@@ -96,7 +140,7 @@ describe("RoomListItemViewModel", () => {
         it.each([
             {
                 label: "unsent message",
-                mock: () => jest.spyOn(notificationState, "isUnsetMessage", "get").mockReturnValue(true),
+                mock: () => jest.spyOn(notificationState, "isUnsentMessage", "get").mockReturnValue(true),
                 expected: "Open room roomName with an unsent message.",
             },
             {