Enables sandbox on about window

ts/context/waitForSettingsChange.ts

@@ -0,0 +1,25 @@
+// Copyright 2021 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { ipcRenderer as ipc } from 'electron';
+
+import { explodePromise } from '../util/explodePromise';
+
+let preferencesChangeResolvers = new Array<() => void>();
+
+ipc.on('preferences-changed', _event => {
+  const resolvers = preferencesChangeResolvers;
+  preferencesChangeResolvers = [];
+
+  for (const resolve of resolvers) {
+    resolve();
+  }
+});
+
+export function waitForSettingsChange(): Promise<void> {
+  const { promise, resolve } = explodePromise<void>();
+
+  preferencesChangeResolvers.push(resolve);
+
+  return promise;
+}