[plt-scheme] windowing, drawing, editor

Hi,
I am currently working on an interface which has to support an editor (1/3 of 
window size), a draw or a picture on which texts must be displayed, 
radio-boxes and things like that.
I tried to build a canvas and started to draw in his dc%, but I've seen I 
cannot put my radio-box objects in this kind of display.
So questions are:
- How can I have a single window with control objects, several text displays 
and a draw or a picture of my draw ?
- How can I maximize a window under linux ?
- Why does (send my-frame refresh) has no effect ? How can I make it refresh 
itself automatically when it is moved or resized ... ?
- How can I make my editor only take 1/3 of the frame space ?

Thank you !