Strategy to make pdf() in R use other devices

This is a multi-part question to SO folks before I engage more with core team.

Summary: On OS X, pdfs should be created using quartz, not postscript. Files are smaller, anti-aliased better, OS fonts including opentype are readily available, encoding is less painful, overall I think it’s a better device. On other platforms, it would be reasonable to use cairo, again a more modern pdf-writing device.

Consider the behavior of the png() device. Although it is allegedly slated to move out of x11.R, it handles c("cairo", "Xlib", "quartz") with a default (options("bitmapType")) set by zzz.R (quartz if capabilities("aqua"), cairo if available, Xlib otherwise). PDF needs to behave the same way, so that in Sweave (or babel or whatever) my pdf figures can be generated using the appropriate device.

My Sweave png patch works because png() takes care of getting the device option. An earlier version of the patch (which I still use) flips the device in Sweave, but I was smacked down for this and I know it’s sort of the wrong the place to do it.

pdf.orig = pdf

pdf = function(...) {
    // Insert code here
}