lotus(#2): stream per-participant call state over widget API

Opt-in (lotusCallState=1) bridge that emits io.lotus.call_state with each participant's speaking/audio/video state, so the Lotus host can drive speaking rings / mute badges / PiP from real events instead of scraping EC's rendered DOM. Exposes vm.userMedia$ on the public CallViewModel. Additive: no-op without the flag. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-06-29 23:05:20 -04:00
parent 39377fb6e1
commit 444af5f7ac
4 changed files with 146 additions and 0 deletions
@@ -0,0 +1,70 @@
+/*
+Copyright 2026 Lotus Guild
+
+SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+Please see LICENSE in the repository root for full details.
+*/
+
+import { combineLatest, of, type Subscription } from "rxjs";
+import { distinctUntilChanged, map, switchMap, throttleTime } from "rxjs/operators";
+
+import { type CallViewModel } from "../state/CallViewModel/CallViewModel";
+import { LotusWidgetActions, lotusFlag, lotusSendToHost } from "./lotusWidget";
+
+interface ParticipantState {
+  /** Opaque media id (stable per tile). */
+  id: string;
+  /** Matrix user id this media belongs to. */
+  userId: string;
+  speaking: boolean;
+  audioEnabled: boolean;
+  videoEnabled: boolean;
+}
+
+/**
+ * Stream per-participant speaking / mute / camera state to the Lotus host
+ * (cinny) over the widget API, so the host can drive speaking rings, mute
+ * badges and PiP from real events instead of scraping Element Call's rendered
+ * DOM (`useCallSpeakers.ts`).
+ *
+ * Opt-in: does nothing unless the host set `lotusCallState=1` on the widget
+ * URL. Returns a teardown function.
+ */
+export function startLotusCallState(vm: CallViewModel): () => void {
+  if (!lotusFlag("lotusCallState")) return () => undefined;
+
+  const sub: Subscription = vm.userMedia$
+    .pipe(
+      switchMap((members) =>
+        members.length === 0
+          ? of([] as ParticipantState[])
+          : combineLatest(
+              members.map((m) =>
+                combineLatest([
+                  m.speaking$,
+                  m.audioEnabled$,
+                  m.videoEnabled$,
+                ]).pipe(
+                  map(
+                    ([speaking, audioEnabled, videoEnabled]): ParticipantState => ({
+                      id: m.id,
+                      userId: m.userId,
+                      speaking,
+                      audioEnabled,
+                      videoEnabled,
+                    }),
+                  ),
+                ),
+              ),
+            ),
+      ),
+      // `speaking` flips rapidly; cap the send rate and drop no-op repeats.
+      throttleTime(150, undefined, { leading: true, trailing: true }),
+      distinctUntilChanged((a, b) => JSON.stringify(a) === JSON.stringify(b)),
+    )
+    .subscribe((participants) => {
+      lotusSendToHost(LotusWidgetActions.CallState, { participants });
+    });
+
+  return () => sub.unsubscribe();
+}