Support for room upgrades

* Show when a room upgrade is needed
 * Dialog box to perform the upgrade

src/components/views/rooms/RoomUpgradeWarningBar.js

@@ -0,0 +1,57 @@
+/*
+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 React from 'react';
+import PropTypes from 'prop-types';
+import sdk from '../../../index';
+import Modal from '../../../Modal';
+
+import { _t } from '../../../languageHandler';
+
+module.exports = React.createClass({
+    displayName: 'RoomUpgardeWarningBar',
+
+    propTypes: {
+        room: PropTypes.object.isRequired,
+    },
+
+    onUpgradeClick: function() {
+        const RoomUpgradeDialog = sdk.getComponent('dialogs.RoomUpgradeDialog');
+        Modal.createTrackedDialog('Upgrade Room Version', '', RoomUpgradeDialog, {room: this.props.room});
+    },
+
+    render: function() {
+        const AccessibleButton = sdk.getComponent('elements.AccessibleButton');
+        return (
+            <div className="mx_RoomUpgradeWarningBar">
+                <div className="mx_RoomUpgradeWarningBar_header">
+                    {_t("There is a known vulnerability affecting this room.")}
+                </div>
+                <div className="mx_RoomUpgradeWarningBar_body">
+                    {_t("This room version is vulnerable to malicious modification of room state.")}
+                </div>
+                <p className="mx_RoomUpgradeWarningBar_upgradelink">
+                    <AccessibleButton onClick={this.onUpgradeClick}>
+                        {_t("Click here to upgrade to the latest room version and ensure room integrity is protected.")}
+                    </AccessibleButton>
+                </p>
+                <div className="mx_RoomUpgradeWarningBar_small">
+                    {_t("Only room administrators will see this warning")}
+                </div>
+            </div>
+        );
+    },
+});