How to modify a Widget

[JumBê]

Hi

I wanted to modify the widget of problems by severity.

I have a couple of nested groups. I want to give the widget the ability to use tree views, in such a way that i could see a group of hosts in one line, and then expand it to see its nested subgroups. I believe i want to modifty at the CWidgetFormProblemsBySv.php at least, but I'm not sure what else will I have to deal with.

Any general guidelines for what would be needed to accomplish this?

Thanks for the attention