Pango: Specifying width of text

[Lars Ræder <larsrc gmail com>]

Hi!

I have been wanting a way to specify that text should be of a certain
width, for use in Dia where text is frequently rendered inside boxes. 
Problem is that at different zoom levels, the fonts don't scale
linearly, as so may leave gaps or worse overflow the boxes.  Pango
previously had no way to do this, so we've had to resort to tweaking
the font size until it's close enough.  I see that in Pango 1.6 at
least pango_layout_set_width lets you set the _wrap_ width, and
pango_layout_set_justify lets you set text to expand to fill a certain
width.  Is that width the same as the wrap width?  And if the text
scales so as to be too wide, will it be squeezed to fit inside the
width, or wrapped?

Thanks,
-Lars