[wxhaskell-users] quasibug on dcGetPixel

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Hi Daan. Thanks for the information about creating the wxcXXX.hs files. This 
time I report a quasi-nonbug, since it is no possible to watch all the methods 
are correctly typed. In the automatically generated wxcClasses, dcGetPixel is 
given this type:

  dcGetPixel :: DC a -> Point -> Color -> IO Int

However, this is absurd since we are getting, not putting, the pixel color.
I do not know the way your marshaling code generator works, but making an ad 
hoc fix whenever necessary is straightforward:

  import Graphics.UI.WXH  
  import qualified Graphics.UI.WXH.WxcTypes as WXHT
  foreign import ccall "wxDC_GetPixel" wxDC_GetPixel
     :: DC a -> CInt -> CInt -> WXHT.ColourObject c -> IO CInt
  newDCGetPixel :: DC a -> Point -> IO Color
  newDCGetPixel dc p = WXHT.withRefColour $
    \col->(wxDC_GetPixel dc (WXHT.toCIntPointX p) (WXHT.toCIntPointY p) col)
    >> return ()

Next point: I think it is very annoying that wxDC objects cannot be persistent. 
The entire state needs to be set everytime you want to draw. In order to fix 
it, I have been developing for my library some code for marshalling a wxDC 
state (yours in WXH.Draw is incomplete, lacks background brush, clipping and 
logical function state), in order to give windows persistent wxDC states. 
Everytime I create a wxDC, I transfer the previously saved state to it, and 
vice versa. However, my code needs to attach someway this state to the window. 
I do this by defining my drawable controls as records and storing the state in 
a IORef in a field of the record, but I do not know if it is possible to attach 
Haskell data someway to a (Window a) object, which you use to represent and 
handle controls. If it is possible and you think of the wxDC non persistent 
behaviour as me, I wonder you would want my code for modifying your WX.Draw 
interface



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