[cairo] gtk, cairo and surfaces

[Donn]

Hi,
Sorry if I am being thick, but I can't get anywhere with this. I am scraping 
the net far and wide, so perhaps something will come-up.

I am using pygtk and python-cairo. I have a DrawingArea which gets an expose 
event. In that event one draws stuff with a context; there is no hint of 
where/what the surface is (I can't find any).

I want to output a png of what is being drawn to the window. Can anyone point 
me in the right direction?

Some code:

class Stack(gtk.DrawingArea):

...stuff...

def _expose(self, widget, event):
	self.context = widget.window.cairo_create()

	Draw stuff to self.context ...

	## I want a "copy" of the DrawingArea written out
	## to a PNG file as well.
	## This code writes blanks, not sure why:
	out = cairo.ImageSurface(cairo.FORMAT_ARGB32,self.w,self.h)
	ctxout = cairo.Context( out )

	## Trying to 'capture' my self.context into a pattern.
	self.context.push_group()
	p=self.context.pop_group()

	ctxout.set_source( p )
	ctxout.paint()
		
	out.write_to_png("somefile%d.png" % self.outpic )
	self.outpic += 1

	return True

Thanks,
\d
-- 
home: http://otherwise.relics.co.za/
https://savannah.nongnu.org/projects/things/
https://savannah.nongnu.org/projects/fontypython/