Convert LanguageDropdown to TS

Signed-off-by: Šimon Brandner <simon.bra.ag@gmail.com>

src/components/views/elements/LanguageDropdown.tsx

@@ -0,0 +1,128 @@
+/*
+Copyright 2017 Marcel Radzio (MTRNord)
+Copyright 2017 Vector Creations 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 React from 'react';
+
+import * as languageHandler from '../../../languageHandler';
+import SettingsStore from "../../../settings/SettingsStore";
+import { _t } from "../../../languageHandler";
+import { replaceableComponent } from "../../../utils/replaceableComponent";
+import Spinner from "./Spinner";
+import Dropdown from "./Dropdown";
+
+function languageMatchesSearchQuery(query, language) {
+    if (language.label.toUpperCase().includes(query.toUpperCase())) return true;
+    if (language.value.toUpperCase() === query.toUpperCase()) return true;
+    return false;
+}
+
+interface IProps {
+    className?: string;
+    onOptionChange: (language: string) => void;
+    value?: string;
+    disabled?: boolean;
+}
+
+interface IState {
+    searchQuery: string;
+    langs: string[];
+}
+
+@replaceableComponent("views.elements.LanguageDropdown")
+export default class LanguageDropdown extends React.Component<IProps, IState> {
+    constructor(props: IProps) {
+        super(props);
+
+        this.state = {
+            searchQuery: '',
+            langs: null,
+        };
+    }
+
+    public componentDidMount(): void {
+        languageHandler.getAllLanguagesFromJson().then((langs) => {
+            langs.sort(function(a, b) {
+                if (a.label < b.label) return -1;
+                if (a.label > b.label) return 1;
+                return 0;
+            });
+            this.setState({ langs });
+        }).catch(() => {
+            this.setState({ langs: ['en'] });
+        });
+
+        if (!this.props.value) {
+            // If no value is given, we start with the first
+            // country selected, but our parent component
+            // doesn't know this, therefore we do this.
+            const language = languageHandler.getUserLanguage();
+            this.props.onOptionChange(language);
+        }
+    }
+
+    private onSearchChange = (search: string): void => {
+        this.setState({
+            searchQuery: search,
+        });
+    };
+
+    public render(): JSX.Element {
+        if (this.state.langs === null) {
+            return <Spinner />;
+        }
+
+        let displayedLanguages;
+        if (this.state.searchQuery) {
+            displayedLanguages = this.state.langs.filter((lang) => {
+                return languageMatchesSearchQuery(this.state.searchQuery, lang);
+            });
+        } else {
+            displayedLanguages = this.state.langs;
+        }
+
+        const options = displayedLanguages.map((language) => {
+            return <div key={language.value}>
+                { language.label }
+            </div>;
+        });
+
+        // default value here too, otherwise we need to handle null / undefined
+        // values between mounting and the initial value propgating
+        let language = SettingsStore.getValue("language", null, /*excludeDefault:*/true);
+        let value = null;
+        if (language) {
+            value = this.props.value || language;
+        } else {
+            language = navigator.language || navigator.userLanguage;
+            value = this.props.value || language;
+        }
+
+        return <Dropdown
+            id="mx_LanguageDropdown"
+            className={this.props.className}
+            onOptionChange={this.props.onOptionChange}
+            onSearchChange={this.onSearchChange}
+            searchEnabled={true}
+            value={value}
+            label={_t("Language Dropdown")}
+            disabled={this.props.disabled}
+        >
+            { options }
+        </Dropdown>;
+    }
+}
+