migrate file and image widgets

packages/netlify-cms-widget-image/src/ImagePreview.js

@@ -0,0 +1,22 @@
+import React from 'react';
+import PropTypes from 'prop-types';
+import styled from 'react-emotion';
+import { WidgetPreviewContainer } from 'netlify-cms-ui-default';
+
+const Image = styled.img`
+  max-width: 100%;
+  height: auto;
+`
+
+const ImagePreview = ({ value, getAsset }) => (
+  <WidgetPreviewContainer>
+    { value ? <Image src={getAsset(value)} role="presentation"/> : null}
+  </WidgetPreviewContainer>
+);
+
+ImagePreview.propTypes = {
+  getAsset: PropTypes.func.isRequired,
+  value: PropTypes.node,
+};
+
+export default ImagePreview;

packages/netlify-cms-widget-image/src/index.js

@@ -0,0 +1,4 @@
+import { withFileControl } from 'netlify-cms-widget-file';
+
+export const ImageControl = withFileControl({ forImage: true });
+export ImagePreview from './ImagePreview';