riot-desktop open SSO in browser so user doesn't have to auth twice

src/components/views/elements/SSOButton.js

@@ -0,0 +1,41 @@
+/*
+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 React from 'react';
+import PropTypes from 'prop-types';
+
+import PlatformPeg from "../../../PlatformPeg";
+import AccessibleButton from "./AccessibleButton";
+import {_t} from "../../../languageHandler";
+
+const SSOButton = ({matrixClient, loginType, ...props}) => {
+    const onClick = () => {
+        PlatformPeg.get().startSingleSignOn(matrixClient, loginType);
+    };
+
+    return (
+        <AccessibleButton {...props} kind="primary" onClick={onClick}>
+            {_t("Sign in with single sign-on")}
+        </AccessibleButton>
+    );
+};
+
+SSOButton.propTypes = {
+    matrixClient: PropTypes.object.isRequired, // does not use context as may use a temporary client
+    loginType: PropTypes.oneOf(["sso", "cas"]), // defaults to "sso" in base-apis
+};
+
+export default SSOButton;