Support sending hidden read receipts

src/components/structures/TimelinePanel.js

@@ -685,20 +685,25 @@ const TimelinePanel = createReactClass({
             }
             this.lastRMSentEventId = this.state.readMarkerEventId;
 
+            const hiddenRR = !SettingsStore.getValue("sendReadReceipts");
+
             debuglog('TimelinePanel: Sending Read Markers for ',
                 this.props.timelineSet.room.roomId,
                 'rm', this.state.readMarkerEventId,
                 lastReadEvent ? 'rr ' + lastReadEvent.getId() : '',
+                ' hidden:' + hiddenRR,
             );
             MatrixClientPeg.get().setRoomReadMarkers(
                 this.props.timelineSet.room.roomId,
                 this.state.readMarkerEventId,
                 lastReadEvent, // Could be null, in which case no RR is sent
+                {hidden: hiddenRR},
             ).catch((e) => {
                 // /read_markers API is not implemented on this HS, fallback to just RR
                 if (e.errcode === 'M_UNRECOGNIZED' && lastReadEvent) {
                     return MatrixClientPeg.get().sendReadReceipt(
                         lastReadEvent,
+                        {hidden: hiddenRR},
                     ).catch((e) => {
                         console.error(e);
                         this.lastRRSentEventId = undefined;

src/components/views/settings/tabs/user/LabsUserSettingsTab.js

@@ -54,6 +54,7 @@ export default class LabsUserSettingsTab extends React.Component {
                     <SettingsFlag name={"enableWidgetScreenshots"} level={SettingLevel.ACCOUNT} />
                     <SettingsFlag name={"showHiddenEventsInTimeline"} level={SettingLevel.DEVICE} />
                     <SettingsFlag name={"lowBandwidth"} level={SettingLevel.DEVICE} />
+                    <SettingsFlag name={"sendReadReceipts"} level={SettingLevel.ACCOUNT} />
                 </div>
             </div>
         );

src/i18n/strings/en_EN.json

@@ -367,6 +367,7 @@
     "Show hidden events in timeline": "Show hidden events in timeline",
     "Low bandwidth mode": "Low bandwidth mode",
     "Allow fallback call assist server turn.matrix.org when your homeserver does not offer one (your IP address would be shared during a call)": "Allow fallback call assist server turn.matrix.org when your homeserver does not offer one (your IP address would be shared during a call)",
+    "Send read receipts for messages (requires compatible homeserver to disable)": "Send read receipts for messages (requires compatible homeserver to disable)",
     "Collecting app version information": "Collecting app version information",
     "Collecting logs": "Collecting logs",
     "Uploading report": "Uploading report",

src/settings/Settings.js

@@ -394,4 +394,11 @@ export const SETTINGS = {
         // This is a tri-state value, where `null` means "prompt the user".
         default: null,
     },
+    "sendReadReceipts": {
+        supportedLevels: LEVELS_ACCOUNT_SETTINGS,
+        displayName: _td(
+            "Send read receipts for messages (requires compatible homeserver to disable)",
+        ),
+        default: true,
+    },
 };