Track if user has participated in a thread or not

src/@types/event.ts

@@ -115,11 +115,13 @@ export enum MsgType {
     KeyVerificationRequest = "m.key.verification.request",
 }
 
+/* eslint-disable camelcase */
 export interface IThreadBundledRelation {
-    // eslint-disable-next-line camelcase
     latest_event: IEvent;
     count: number;
+    current_user_participated?: boolean;
 }
+/* eslint-enable camelcase */
 
 export const RoomCreateTypeField = "type";
 

src/models/thread.ts

@@ -42,6 +42,7 @@ export class Thread extends TypedEventEmitter<ThreadEvent> {
     private _head: MatrixEvent;
     private eventToPreview: MatrixEvent = null;
     private replyCount = 0;
+    private _currentUserParticipated = false;
 
     public _hasServerSideSupport = false;
 
@@ -207,6 +208,7 @@ export class Thread extends TypedEventEmitter<ThreadEvent> {
             });
             EventTimeline.setEventMetadata(this.eventToPreview, this.roomState, false);
             this.replyCount = threadBundle.count;
+            this._currentUserParticipated = threadBundle.current_user_participated === true;
         } else {
             this.addEvent(this._head);
             this.replyCount = 0;
@@ -269,6 +271,10 @@ export class Thread extends TypedEventEmitter<ThreadEvent> {
             this.emit(ThreadEvent.NewReply, this, event);
         }
 
+        if (!this._currentUserParticipated) {
+            this._currentUserParticipated = event.getSender() === this.client.getUserId();
+        }
+
         this.emit(ThreadEvent.Update, this);
         this.emit(ThreadEvent.New, this);
     }
@@ -332,4 +338,8 @@ export class Thread extends TypedEventEmitter<ThreadEvent> {
     public get ready(): boolean {
         return this._ready;
     }
+
+    public get currentUserParticipated(): boolean {
+        return this._currentUserParticipated;
+    }
 }