[gtkmm] Pixbuf contents

[Silviu D Minut <minutsil cse msu edu>]

I asked this question a couple of days ago, and I didn't get an answer, so
I thought I'd try again.

I'm displaying an image in a pixbuf, and later on, when the user clicks on
the image I need to change the contents of the pixbuf, in a rectangle
around that point. How would I do that? Is pixbuf not appropriate for what
I want to do?

Thanks!