FYI: As we thought, preserving the read-only status is trivial.

On the calendar-backend side (calaccess.cc), we need to set the read-only flag when we create the local calendar (third parameter to mc->addCalendar, currently hard coded to false). Obviously cwrapper.py needs to be updated accordingly.

Before we create the calendar in erminig-ng, we just read 'cal.access_level.value'. Simple approach would be if it is set to "read", then create the local calendar read-only. A more complete approach would be to consider all possible values which might indicate that we don't have any access to the calendar (then why is it in the feed?) or that we only have access to free/busy information from the calendar.

I did this in a quick hack and it does work, setting the "US Holidays" shared calendar from google as read-only locally. If I try to add a new event on the n900, it doesn't present the "US Holidays" calendar as an option.

I'm assuming the code is somewhat in flux as lorelei is flushing out the initial features and GUI. If you want me to throw together a patch now, let me know. Otherwise I'll wait until core features are flushed out, including a GUI.