Fix focus on Modal (#4014)

* Fix focus on Modal #3814

* PR Grumble

js/src/ui/Modal/modal.js

@@ -18,6 +18,7 @@ import { Dialog } from 'material-ui';
 import React, { Component, PropTypes } from 'react';
 import { connect } from 'react-redux';
 import { bindActionCreators } from 'redux';
+import ReactDOM from 'react-dom';
 
 import { nodeOrStringProptype } from '~/util/proptypes';
 
@@ -49,6 +50,14 @@ class Modal extends Component {
     waiting: PropTypes.array
   }
 
+  componentDidMount () {
+    const element = ReactDOM.findDOMNode(this.refs.dialog);
+
+    if (element) {
+      element.focus();
+    }
+  }
+
   render () {
     const { muiTheme } = this.context;
     const { actions, busy, children, className, current, compact, settings, steps, title, visible, waiting } = this.props;
@@ -85,9 +94,12 @@ class Modal extends Component {
         <Container
           compact={ compact }
           light
+          ref='dialog'
           style={
             { transition: 'none' }
-          }>
+          }
+          tabIndex={ 0 }
+        >
           { children }
         </Container>
       </Dialog>