Debian Multimedia :: Make A Dialog With Zenity Which Would Show An Updating List?

Is there a way to make a dialog with zenity which would show an updating list? Zenity does it with progress, but I didn't figure out if it's possible to do it with the list. I.e. for example, I want to monitor something, and update the dialog with new list periodically. Is it even possible? zenity can wait for data from stdin, but it just adds stuff to the list. May be there are some control sequences which clear the list in the dialog?

For example:

{ echo "Foo"; sleep 2; echo "Bar"; } | zenity --list --title='Dynamic list?' --text='Some data' --column='values'

How can I instead of adding Bar, replace the Foo with it?