componentDidUpdate(previousProps) {
  previousProps.children.forEach( child => {
    let domNode = ReactDOM.findDOMNode( this.refs[child.key] );

    const newBox = domNode.getBoundingClientRect();
    const oldBox = this.state[key];

    const deltaX = oldBox.left - newBox.left;
    const deltaY = oldBox.top  - newBox.top;

    requestAnimationFrame( () => {
      domNode.style.transform  = `translate(${deltaX}px, ${deltaY}px)`;
      domNode.style.transition = 'transform 0s';

      requestAnimationFrame( () => {
        // In order to get the animation to play, we'll need to wait for
        // the 'invert' animation frame to finish, so that its inverted
        // position has propagated to the DOM.
        //
        // Then, we just remove the transform, reverting it to its natural
        // state, and apply a transition so it does so smoothly.
        domNode.style.transform  = '';
        domNode.style.transition = 'transform 500ms';
      });
    });
  });
}