how to make treegrids button friendly?

Hi,

I would like to extend the web client to support buttons in tree with field_parent set.

Could someone give me a hand in this? If you could summarize the classes used in the current setting, and a one-word description of what they actually do, I could probably do the rest, and change the code.

I already know that 1. widgets/tree_view and widgets/treegrid should be "button" aware. But I don't really know what their purpose is exactly. And what does controllers/tree does afterwards.

Anyway, here are my guesses:
* widgets/tree_view processes a request response related to a tree_view, the widgets/treegrid catches the header part of the tree
* If the previous is true, then I see how to add a new columns to the tree, but that gives an error in the controller, as the button-field can not be found as a field.
* I guess that controllers/tree would handle the data part, but how can I pass details to it?
* using the web client logs, I guess that the tree controller is launched via a json call. is this true?

thanks for your support