I've got the beginnings of another plugin idea, which I am tentatively exploring the feasibility of. It is to do with producing statistical graphs/reports of books in your library. At its simplest it would be not dissimilar to what you get on Goodreads for instance allowing you to see books read by time periods (assuming you have a date read column), or books by date published, books by date added etc. In theory you could do books by genre tags or whatever etc as well, just really down to what people would find interesting.
However when it comes to graphing using Qt, according to the FAQ they say you are basically on your own, and suggest including some third party libraries.
link
I don't think that me compiling up a Qt library and including in a plugin is likely to work very well, methinks there be dragons in there (compilation/cross platform etc) even if technically it did work. I've only bundled python libraries such as with Goodreads Sync previously, not C++ dlls.
So the question is most likely for Kovid - do you perchance already include any Qt graphing libraries currently in your calibre distribution, and if not would you have any interest in adding to your build process to do so? Perhaps you may have some feature in mind for calibre down the line which might use it? Or do you have any alternative suggestions?
If it all falls into the too hard basket I'll just forget the whole idea - I have close enough to what I need from Goodreads currently.