[cairo] Language bindings doc

[Bill Spitzak]

Carl Worth wrote:

> As far as naming that type, I've intentionally avoided using the word
> "solid" in the cairo API, (although we do use "solid" within the
> implementation to refer to single-color patterns). I've avoided this
> term in the public API because of the possibility that "solid" might
> be interpreted as "opaque" rather than the "single, uniform color"
> sense that is intended.
> 
> But I can't really think of better name than "solid" anyway. We
> avoided the problem within cairo's API by simply not having names for
> pattern sub-types, but here, obviously some name is necessary.

In our image processing software I used "Constant", for the same reasons 
of confusion as to what "solid" might mean. Not sure if that is any 
better. In Cairo after you create such a pattern, can you change the 
color? Or do you destroy it and create another? If the second than 
"constant" may make sense.