My thanks to all of you who pointed me at the :single-box argument for with-output-as-presentation. And an extra thank-you to Paolo for the ksnapshot pointer.
A quick question, though, and this is not intended as a flame --- is this problem a manifestation of some issues with programming (Mc)CLIM?
My impression is that there are two challenges to programming with McCLIM:
1. The paradigm is radically different from any other interface coding framework.
This certainly isn't a killer for me, because I happily used Garnet for many years (and if I understood X well enough to modernize its back-end, I would probably go back to it today).
2. There seems to be an awful lot of black art to getting a CLIM UI to look right and behave in ways that users will perceive as normal.
I don't have a good read on how much this is because McCLIM is still evolving, and how much this is because of the nature of the CLIM beast. Do we need better defaults to make things happen more naturally? How feasible would that be if we want to comply with the CLIM spec? Or should we provide macrology to wrap things up more easily for new CLIM programmers? I'm still fumbling around myself, so I find it hard to say what would make things easier, since I might just be doing things wrong.
Best, R