Add DialogButton component

A component to normalise the buttons in dialogs.

src/components/views/elements/DialogButtons.js

@@ -0,0 +1,61 @@
+/*
+Copyright 2015, 2016 OpenMarket 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.
+*/
+
+"use strict";
+
+import React from "react";
+import { _t } from '../../../languageHandler';
+
+/**
+ * Basic container for buttons in modal dialogs.
+ */
+module.exports = React.createClass({
+    displayName: "DialogButtons",
+
+    propTypes: {
+        // The primary button which is styled differently and has default focus.
+        primaryButton: React.PropTypes.node.isRequired,
+
+        // onClick handler for the primary button.
+        onPrimaryButtonClick: React.PropTypes.func.isRequired,
+
+        // onClick handler for the cancel button.
+        onCancel: React.PropTypes.func.isRequired,
+
+        focus: React.PropTypes.bool,
+    },
+
+    render: function() {
+        let primaryButtonClassName = "mx_Dialog_primary";
+        if (this.props.primaryButtonClass) {
+            primaryButtonClassName += " " + this.props.primaryButtonClass;
+        }
+        return (
+            <div className="mx_Dialog_buttons">
+                <button className={primaryButtonClassName}
+                    onClick={this.props.onPrimaryButtonClick}
+                    autoFocus={this.props.focus}
+                >
+                    { this.props.primaryButton }
+                </button>
+                { this.props.children }
+                <button onClick={this.props.onCancel}>
+                    { _t("Cancel") }
+                </button>
+            </div>
+        );
+    },
+});