var VerticalCenter = React.createClass({
  render: function() {
    return this.transferPropsTo(
      <AutoLayout>
        <Box name="inner" height="inner[intrinsic-height]" centerY="this[centerY]">{this.props.children}</Box>
      </AutoLayout>
    );
  }
});

var App = React.createClass({
  render: function() {
    // You can prefix the props on Box with >= or <= for more control
    return (
      <AutoLayout top="window[top]" bottom="window[bottom]" left="window[left]" right="window[right]">
        <Box
          name="heading"
          left="this[left]"
          right="this[right]"
          top="this[top]"
          height="heading[intrinsic-height]">
          <h1>Heading</h1>
        </Box>
        <Box
          name="leftNav"
          right="heading[left] + 64"
          top="heading[bottom]"
          left="this[left]">
          <div>Left nav</div>
        </Box>
        <Box
          name="content"
          left="leftNav[right]"
          right="this[right]"
          top="leftNav[top]"
          bottom="this[bottom]">
          <VerticalCenter><div>Content</div></VerticalCenter>
        </Box>
      </AutoLayout>
    );
  }
});