Factor out generic EventListSummary from MELS

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

src/hooks/useStateToggle.js

@@ -0,0 +1,27 @@
+/*
+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 {useState} from 'react';
+
+// Hook to simplify toggling of a boolean state value
+// Returns value, method to toggle boolean value and method to set the boolean value
+export const useStateToggle = (initialValue) => {
+    const [value, setValue] = useState(Boolean(initialValue));
+    const toggleValue = () => {
+        setValue(!value);
+    };
+    return [value, toggleValue, setValue];
+};