Create a proper one-on-one call layout for portrait screens

src/state/OneOnOnePortraitLayout.ts

@@ -0,0 +1,43 @@
+/*
+Copyright 2024 New Vector Ltd.
+Copyright 2026 Element Creations Ltd.
+
+SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+Please see LICENSE in the repository root for full details.
+*/
+
+import { type BehaviorSubject } from "rxjs";
+
+import {
+  type Alignment,
+  type OneOnOnePortraitLayout,
+  type OneOnOnePortraitLayoutMedia,
+} from "./layout-types";
+import { type TileStore } from "./TileStore";
+import { type Behavior } from "./Behavior";
+
+/**
+ * Produces a one-on-one portrait layout with the given media.
+ */
+export function oneOnOnePortraitLayout(
+  media: OneOnOnePortraitLayoutMedia,
+  pipSize$: Behavior<"sm" | "lg">,
+  pipAlignment$: BehaviorSubject<Alignment>,
+  prevTiles: TileStore,
+): [OneOnOnePortraitLayout, TileStore] {
+  const update = prevTiles.from(media.pip === undefined ? 0 : 1);
+  update.registerSpotlight([media.spotlight], true);
+  if (media.pip !== undefined) update.registerGridTile(media.pip);
+  const tiles = update.build();
+
+  return [
+    {
+      type: media.type,
+      spotlight: tiles.spotlightTile!,
+      pip: media.pip && tiles.gridTilesByMedia.get(media.pip),
+      pipSize$,
+      pipAlignment$,
+    },
+    tiles,
+  ];
+}