Clean up E2EIcon for better maintainability

src/hooks/useSettings.js

@@ -0,0 +1,52 @@
+/*
+Copyright 2020 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, useState} from "react";
+import SettingsStore from '../settings/SettingsStore';
+
+// Hook to fetch the value of a setting and dynamically update when it changes
+export const useSettingValue = (settingName, roomId = null, excludeDefault = false) => {
+    const [value, setValue] = useState(SettingsStore.getValue(settingName, roomId, excludeDefault));
+
+    useEffect(() => {
+        const ref = SettingsStore.watchSetting(settingName, roomId, () => {
+            setValue(SettingsStore.getValue(settingName, roomId, excludeDefault));
+        });
+        // clean-up
+        return () => {
+            SettingsStore.unwatchSetting(ref);
+        };
+    }, [settingName, roomId, excludeDefault]);
+
+    return value;
+};
+
+// Hook to fetch whether a feature is enabled and dynamically update when that changes
+export const useFeatureEnabled = (featureName, roomId = null) => {
+    const [enabled, setEnabled] = useState(SettingsStore.isFeatureEnabled(featureName, roomId));
+
+    useEffect(() => {
+        const ref = SettingsStore.watchSetting(featureName, roomId, () => {
+            setEnabled(SettingsStore.isFeatureEnabled(featureName, roomId));
+        });
+        // clean-up
+        return () => {
+            SettingsStore.unwatchSetting(ref);
+        };
+    }, [featureName, roomId]);
+
+    return enabled;
+};