Switch widget resizing to re-resizable and add persistence

src/hooks/useLocalStorage.ts

@@ -0,0 +1,37 @@
+/*
+Copyright 2019 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 {useEffect, useRef, useState} from "react";
+
+// Hook behaving like useState but persisting the value to localStorage. Returns same as useState
+export const useLocalStorageState = (key: string, initialValue: boolean) => {
+    const lsKey = useRef("useLocalStorageState_" + key).current;
+
+    const [value, setValue] = useState(() => {
+        try {
+            const item = window.localStorage.getItem(lsKey);
+            return item ? JSON.parse(item) : initialValue;
+        } catch (error) {
+            return initialValue;
+        }
+    });
+
+    useEffect(() => {
+        window.localStorage.setItem(lsKey, JSON.stringify(value));
+    }, [lsKey, value]);
+
+    return [value, setValue];
+};