Filter membership/profile/topic events in public rooms

Author: bxdxnn

apps/web/src/shouldHideEvent.ts

@@ -6,10 +6,11 @@ SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Com
 Please see LICENSE files in the repository root for full details.
  */
 
-import { type MatrixEvent, EventType, RelationType, M_POLL_END } from "matrix-js-sdk/src/matrix";
+import { type MatrixEvent, EventType, RelationType, JoinRule, M_POLL_END } from "matrix-js-sdk/src/matrix";
 import { KnownMembership } from "matrix-js-sdk/src/types";
 
 import SettingsStore from "./settings/SettingsStore";
+import MatrixClientPeg from "./MatrixClientPeg";
 import { type IRoomState } from "./components/structures/RoomView";
 import { type SettingKey } from "./settings/Settings.tsx";
 
@@ -43,6 +44,11 @@ function memberEventDiff(ev: MatrixEvent): IDiff {
     return diff;
 }
 
+function isPublicRoom(ev: MatrixEvent): boolean {
+    const room = MatrixClientPeg.get().getRoom(ev.getRoomId());
+    return room?.getJoinRule() === JoinRule.Public;
+}
+
 /**
  * Determines whether the given event should be hidden from timelines.
  * @param ev The event
@@ -53,6 +59,8 @@ export default function shouldHideEvent(ev: MatrixEvent, ctx?: IRoomState): bool
     // Hide all poll end events
     if (M_POLL_END.matches(ev.getType())) return true;
 
+    if (ev.getType() === EventType.RoomTopic && isPublicRoom(ev)) return true;
+
     // Accessing the settings store directly can be expensive if done frequently,
     // so we should prefer using cached values if a RoomContext is available
     const isEnabled = ctx
@@ -70,6 +78,8 @@ export default function shouldHideEvent(ev: MatrixEvent, ctx?: IRoomState): bool
     const eventDiff = memberEventDiff(ev);
 
     if (eventDiff.isMemberEvent) {
+        if (isPublicRoom(ev)) return true;
+
         if ((eventDiff.isJoin || eventDiff.isPart) && !isEnabled("showJoinLeaves")) return true;
         if (eventDiff.isAvatarChange && !isEnabled("showAvatarChanges")) return true;
         if (eventDiff.isDisplaynameChange && !isEnabled("showDisplaynameChanges")) return true;