[Trinidad] Problems with tr:table SelectionEvent

Hi all,

I need to distinguish between a SelectionEvent delivered when a checkbox is ckecked or when 'Select all' or 'Select None' is clicked. I have been looking into the code and the examples but have not found anything yet (I am surprised that nobody ever needed this feature...).

I have been looking at the internals (javascript) and it seems that there is a hidden input in the generated HTML that has a value "all" or "none" for this purpose. However, when the form is submited in the PPR event, all its hidden fields are cleared and thus, this hidden field never sends its value to the server. Am I wrong? Is this working as it is supposed? Is there any way I can know if the event was generated by clicking the links or the checkbox?

TIA,

-- Rafa