Rewrite frontend using create-react-app

client/WindowSize.js

@@ -0,0 +1,32 @@
+import React, { PropTypes } from 'react'
+import { addEvent, removeEvent } from './DOMUtils'
+
+const ResizeEvent = 'resize'
+
+class WindowSize extends React.Component {
+  static propTypes = {
+    onChange: PropTypes.func
+  }
+
+  handleWindowResize = () => {
+    if (this.props.onChange)
+      this.props.onChange({
+        width: window.innerWidth,
+        height: window.innerHeight
+      })
+  }
+
+  componentDidMount() {
+    addEvent(window, ResizeEvent, this.handleWindowResize)
+  }
+
+  componentWillUnmount() {
+    removeEvent(window, ResizeEvent, this.handleWindowResize)
+  }
+
+  render() {
+    return null
+  }
+}
+
+export default WindowSize