[oe] Using XCB library with cairo

[joaquinduran at adtelecom.es]

Dear all,

Some time ago, Angstrom distribution had configured as virtual/xlib to XCB for some time. Then 
xlib was used again due to instability problems (as I remember) with XCB (I've all emails in 
computer of work but and I writting from home and I don't have access to them).

I think that one focus of instability could be the integration of cairo with XCB. Today I've 
discovered that one of the backends for cairo is XCB, but no cairo package builds it. I would 
like to test it, but one of the troubles is how the configuration options could be determined 
based on virtual/xlib pacakge. Currently I'm thinking in a similar solution to cairo-fpu:

if virtual/xlib = "xcb" then
  EXTRA_OECONF += "--disable-xlib --enable-xcb"
else
  EXTRA_OECONF += "--enable-xlib --disable-xcb"
fi

is this possible? any suggestions?

Thanks and Best Regards,
Joaquim Duran