[wxhaskell-users] Problem with wxHaskell

[Wojtek M. <wo...@cs...>]

  Hello all,

First of all I would like to say that I think that wxHaskell is a great
library. Do you plan to implement OleAutomation object soon?

However, I have a problem. I've been trying to write a small library on top
of wxHaskell, in order to provide very simple drawing capabilities for
people like me, who do not want or need to know about
all the contexts and so on and want just to draw pictures. So I have created
a simple state monad which threads Window () along with ClientDC(). However,
the attached program doesn't work as expected - when the new rectangle is
drawn, the old one turns black. (the important part of Main.hs is testRect
which actually draws things, rest of stuff in Main.hs just computes the
route and colors. What should I change so that the program won't exhibit
this problem?

Wojtek