Use physical keys+layout for shortcuts

ts/services/keyboardLayout.ts

@@ -0,0 +1,31 @@
+// Copyright 2021 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { strictAssert } from '../util/assert';
+
+type LayoutMapType = { get(code: string): string | undefined };
+
+let layoutMap: LayoutMapType | undefined;
+
+export async function initialize(): Promise<void> {
+  strictAssert(layoutMap === undefined, 'keyboardLayout already initialized');
+
+  const experimentalNavigator = (window.navigator as unknown) as {
+    keyboard: { getLayoutMap(): Promise<LayoutMapType> };
+  };
+
+  strictAssert(
+    typeof experimentalNavigator.keyboard?.getLayoutMap === 'function',
+    'No support for getLayoutMap'
+  );
+
+  layoutMap = await experimentalNavigator.keyboard.getLayoutMap();
+}
+
+export function lookup({
+  code,
+  key,
+}: Pick<KeyboardEvent, 'code' | 'key'>): string | undefined {
+  strictAssert(layoutMap !== undefined, 'keyboardLayout not initialized');
+  return layoutMap.get(code) ?? key;
+}