Ok, thanks for the conversation. Maybe I've misunderstood the likely direction of travel of Calibre Companion (and maybe Calibre itself).
On
https://play.google.com/store/apps/d...calibreandroid I read:
"The first application: Calibre Companion supports connecting to calibre over WiFi and be detected by calibre as a device.
...
- Calibre Companion can update the metadata for the books on every connect, ensuring the information is up to date."
This does not sound to me as if "the device is totally passive" as you say. I assumed it was indicative of the likely kinds capabilities that Calibre Companion might develop. Also, the command line capabilities of Calibre (
http://manual.calibre-ebook.com/cli/...ented-commands) show that Calibre can add books to its library, convert books between formats and do other things, all without the GUI running - so why couldn't a device activate such processes, as I gather it can already (via Calibre Companion) alter metadata on the server?
This is all pretty standard client-server thinking: there is no "rule" that says that all activities carried out on a server have to be initiated by a GUI running on the server. And as the Calibre content server already shows, devices can initiate useful interactions such as downloading a version of a book.
Android and similar devices are much more general purpose than a dedicated e-reader. It would be a shame to limit the ambitions of what they might be used for.
Last point (this time around): starting up the Calibre content server can be done (via command line) without running the GUI. So can adding a book to the library. Why shouldn't it be possible to start the wireless device connection (to the library) without having the GUI running, and initiate transfers, conversions and so on? I gather from you that "the device subsystem is part of the GUI", which I hadn't appreciated - but I don't see that has to be so.
Of course "you can call me a dreamer..."
Barry