Detail band resize dynamically vertically when textfield is NULL

Question

I have a JasperReports report build with iReport. I have the normal Detail band but below i have a textField named observations there is sometimes the Observations textField is empty or NULL. I have put both inner components namely textfields, lines into frames something like.

I also set using Print When Expression the below frame the one who holds the Observations textField to appear only when there is data on it this is working very good but the space holds by the frame is still on the Detail and we are losing some space and it's kind annoyng to see this blank space.

Is it possible for the report to "delete" the idle space hold it by the hidden frame?

My report's design:

The generated result (PDF file):

Answer 1

I don't think it's possible to alter the height of a band depending on its content but you can actually have multiple detail bands. So add a new one, move your observation text field into it and set the print when expression of the second band.