Migrate JumpToBottomButton to TypeScript

src/components/views/rooms/JumpToBottomButton.tsx

@@ -0,0 +1,47 @@
+/*
+Copyright 2019 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 React from "react";
+import { _t } from '../../../languageHandler';
+import AccessibleButton from '../elements/AccessibleButton';
+import classNames from 'classnames';
+
+interface IProps {
+    numUnreadMessages: number;
+    highlight: boolean;
+    onScrollToBottomClick: (e: React.MouseEvent) => void;
+}
+
+const JumpToBottomButton: React.FC<IProps> = (props) => {
+    const className = classNames({
+        'mx_JumpToBottomButton': true,
+        'mx_JumpToBottomButton_highlight': props.highlight,
+    });
+    let badge;
+    if (props.numUnreadMessages) {
+        badge = (<div className="mx_JumpToBottomButton_badge">{ props.numUnreadMessages }</div>);
+    }
+    return (<div className={className}>
+        <AccessibleButton
+            className="mx_JumpToBottomButton_scrollDown"
+            title={_t("Scroll to most recent messages")}
+            onClick={props.onScrollToBottomClick}
+        />
+        { badge }
+    </div>);
+};
+
+export default JumpToBottomButton;