Dynamic sizing.

Hello Everyone,

  It seems that right now the easiest and best way to
deal with dynamic sizing of widgets is as follows:

-- CGA/CommonAttributes.hs
class HasSize w where
  size :: Attr w SizeType

data SizeType = Fixed (Int,Int) | Standard

  Where fixed is obviously the pixel size and Standard
is some implementation dependant size.  For example, a
button would likely have a fixed height and a length
based on the label size on a macintosh.  What does
everyone thing about this?  It is pretty elegant and
simple this way so it makes me think that more "stuff"
needs to be added.

David J. Sankel