Consolidate RedactionGrouper and HiddenEventGrouper into MELS (#7739)

src/components/views/elements/GenericEventListSummary.tsx

@@ -0,0 +1,118 @@
+/*
+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.
+*/
+
+import React, { ReactNode, useEffect } from "react";
+import { uniqBy } from "lodash";
+import { MatrixEvent } from "matrix-js-sdk/src/models/event";
+import { RoomMember } from "matrix-js-sdk/src/models/room-member";
+import { logger } from "matrix-js-sdk/src/logger";
+
+import MemberAvatar from '../avatars/MemberAvatar';
+import { _t } from '../../../languageHandler';
+import { useStateToggle } from "../../../hooks/useStateToggle";
+import AccessibleButton from "./AccessibleButton";
+import { Layout } from '../../../settings/enums/Layout';
+
+interface IProps {
+    // An array of member events to summarise
+    events: MatrixEvent[];
+    // The minimum number of events needed to trigger summarisation
+    threshold?: number;
+    // Whether or not to begin with state.expanded=true
+    startExpanded?: boolean;
+    // The list of room members for which to show avatars next to the summary
+    summaryMembers?: RoomMember[];
+    // The text to show as the summary of this event list
+    summaryText?: string | JSX.Element;
+    // An array of EventTiles to render when expanded
+    children: ReactNode[];
+    // Called when the event list expansion is toggled
+    onToggle?(): void;
+    // The layout currently used
+    layout?: Layout;
+}
+
+const GenericEventListSummary: React.FC<IProps> = ({
+    events,
+    children,
+    threshold = 3,
+    onToggle,
+    startExpanded = false,
+    summaryMembers = [],
+    summaryText,
+    layout = Layout.Group,
+}) => {
+    const [expanded, toggleExpanded] = useStateToggle(startExpanded);
+
+    // Whenever expanded changes call onToggle
+    useEffect(() => {
+        if (onToggle) {
+            onToggle();
+        }
+    }, [expanded]); // eslint-disable-line react-hooks/exhaustive-deps
+
+    const eventIds = events.map((e) => e.getId()).join(',');
+
+    // If we are only given few events then just pass them through
+    if (events.length < threshold) {
+        return (
+            <li className="mx_GenericEventListSummary" data-scroll-tokens={eventIds} data-expanded={true} data-layout={layout}>
+                { children }
+            </li>
+        );
+    }
+
+    let body;
+    if (expanded) {
+        body = <React.Fragment>
+            <div className="mx_GenericEventListSummary_line">&nbsp;</div>
+            { children }
+        </React.Fragment>;
+    } else {
+        const uniqueMembers = uniqBy(summaryMembers.filter(member => {
+            if (!member?.getMxcAvatarUrl) {
+                logger.error("EventListSummary given null summaryMember, termites may be afoot eating event senders",
+                    summaryMembers);
+                return false;
+            }
+            return true;
+        }), member => member.getMxcAvatarUrl());
+        const avatars = uniqueMembers.map((m) => <MemberAvatar key={m.userId} member={m} width={14} height={14} />);
+        body = (
+            <div className="mx_EventTile_line">
+                <div className="mx_EventTile_info">
+                    <span className="mx_GenericEventListSummary_avatars" onClick={toggleExpanded}>
+                        { avatars }
+                    </span>
+                    <span className="mx_TextualEvent mx_GenericEventListSummary_summary">
+                        { summaryText }
+                    </span>
+                </div>
+            </div>
+        );
+    }
+
+    return (
+        <li className="mx_GenericEventListSummary" data-scroll-tokens={eventIds} data-expanded={expanded + ""} data-layout={layout}>
+            <AccessibleButton className="mx_GenericEventListSummary_toggle" onClick={toggleExpanded} aria-expanded={expanded}>
+                { expanded ? _t('collapse') : _t('expand') }
+            </AccessibleButton>
+            { body }
+        </li>
+    );
+};
+
+export default GenericEventListSummary;