factor out conditional LanguageSelector as functional component

and reuse in Login, ForgotPassword and Registration views

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

src/components/structures/login/LanguageSelector.js

@@ -0,0 +1,38 @@
+/*
+Copyright 2018 New Vector Ltd
+
+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 SdkConfig from "../../../SdkConfig";
+import {getCurrentLanguage} from "../../../languageHandler";
+import SettingsStore, {SettingLevel} from "../../../settings/SettingsStore";
+import PlatformPeg from "../../../PlatformPeg";
+import sdk from '../../../index';
+import React from 'react';
+
+function onChange(newLang) {
+    if (getCurrentLanguage() !== newLang) {
+        SettingsStore.setValue("language", null, SettingLevel.DEVICE, newLang);
+        PlatformPeg.get().reload();
+    }
+}
+
+export default function makeLanguageSelector() {
+    if (SdkConfig.get()['disable_login_language_selector']) return <div />;
+
+    const LanguageDropdown = sdk.getComponent('views.elements.LanguageDropdown');
+    return <div className="mx_Login_language_div">
+        <LanguageDropdown onOptionChange={onChange} className="mx_Login_language" value={getCurrentLanguage()} />
+    </div>;
+}