Drawing application

["Nilton S. Ramos Quorin" <nilton eletr ufpr br>]

Hello,
I'm writing an application for magnetic field mapping. I'd like to know
if there is some way of stopping a background callback and then plotting
some points on a pixmap on a drawing area. My code reads a value given
by a sensor, and is then supposed to plot it on the pixmap. But it
doesn't. It only plots an array of points sometime later or when the
mapping is done.