How to make popups like in eclipse

[ekadosh]

In my program some of the tooltips have a long text which make them cover the entire screen. I would like to limit them in some way, but without cutting out some of the text.
I thought to do it just like the popups in eclipse (with the F2 for focus). I found out it was implemented with the class PopupDialog or some other derived class, but I couldn't implement it myself.
Does anyone know how to do it?
Is there another idea how to make the tooltip catch only some of the screen?

Thanks.