import __main__
import cairo
import gtk
import math

def expose_event(widget,event):
    cr = widget.window.cairo_create()
    cr.set_source_rgb(0x00 / 255.0, 0x80 / 255.0, 0x80 / 255.0)
    cr.arc(150, 150, 100, 0, 2 * math.pi)
    cr.fill()

win = gtk.Window()
win.connect('destroy', gtk.main_quit)
drawingarea = gtk.DrawingArea()
win.add(drawingarea)
drawingarea.connect('expose_event', expose_event)
drawingarea.set_size_request(300,300)

win.show_all()
gtk.main()