add ui

ui/components/react-splitpane/SplitPaneFillOverlayComponent.js

@@ -0,0 +1,19 @@
+import PropTypes from 'prop-types';
+import classNames from 'classnames';
+
+export default function SplitPaneFillOverlayComponent(props) {
+  const {
+    className,
+    children,
+    ...rest
+  } = props;
+  const cn = classNames(className, 'splitpane-fill');
+  return (
+    <div {...rest} className={cn}>{children}</div>
+  );
+}
+
+SplitPaneFillOverlayComponent.propTypes = {
+  className: PropTypes.string,
+  children: PropTypes.node,
+};