New User Onboarding Task List (#9083)

* Improve type of AccessibleButton to accurately represent available props
* Update analytics events

src/hooks/useIsInitialSyncComplete.ts

@@ -0,0 +1,25 @@
+/*
+Copyright 2022 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { ClientEvent } from "matrix-js-sdk/src/matrix";
+
+import { MatrixClientPeg } from "../MatrixClientPeg";
+import { useEventEmitterState } from "./useEventEmitter";
+
+export function useInitialSyncComplete(): boolean {
+    const cli = MatrixClientPeg.get();
+    return useEventEmitterState(cli, ClientEvent.Sync, () => cli.isInitialSyncComplete());
+}