Custom NodeRendererDefault with different heights

Hi,

Thanks so much for this great library and for helping out!

I would like to customize the nodes so that they each have an open/ closed state. The idea is to have a button on each node which when clicked "opens" the actual node and adds below the title more inputs for editing the node (e.g. notes, dates, priority). This will make the height of the node different than the rest of the node in the tree. When clicking on the button again, the node will be closed and will display only the title and the button (back to the same height as the rest).

You can see an example of opening / closing here: http://kinto.github.io/formbuilder/#/builder (just add a field first).

My initial approach would be to customize the NodeRendererDefault.

My questions:

- Is this the right approach
- Can different nodes have different height?

Thanks!