oo problem

[Tool69]

Thanks James,

It was a matter of choice : in my earlier version, all primitives know
how to draw themselves, but they needed to have a parent and I found it
was not good for aesthetic reasons.

but I think I've been misunderstood. Let's take a concrete sample :

I've got a Paper instance(-5,5,5,5) (the coordinates of lower-left and
upper-right rectangle: xlowleft, ylowlef, xupright, yupright) of my
paper.
I want now to draw an x-axis on it with some ticks and maybe lables, I
need to catch the xlowleft and xupright variables of the Paper inside
my primitive, ok ?
The problem lies inside my primitive, not on the draw method.
Here's a simplified example, I need to retrieve paper.xll and
paper.xur:

class Graduate_x( primitive ):
    def __init__(self, orient = 'se', xorigin = 0, yorigin=0, xunit=
1.0, yunit=1.0):
         primitive.__init__(self)
         for k in range( int(math.floor(( paper.xll - xorigin)/xun)),
int(math.floor((paper.xur-xorigin)/yun)) ):
             ...something to construct my path