Finding white space or line break candidates using Pango?

["Leon Woestenberg" <leon woestenberg gmail com>]

Hello,

using Pango, I would like to layout a infinitely long (UTF-8 encoded)
text piece by piece (as it scrolls by), and my best guess would be to
do this at white space, or line break candidates.

Is there a function available that helps me in Pango, or should I use
some C library function?

Best regards,
-- 
Leon