Originally Posted by madnick
I use a 64GB Cyanogen Mod card in my Nook HD+. USB Mass Storage mode is not supported, so Calibre cannot see the device when connected. I purchases Calibre Companion to transfer files wirelessly and it works well for that.
I travel with my Nook and keep only the books I need to read on my device while the main library stays in Calibre. When I have finished a book, I delete it off the device. In the past, with several devices including the HD+ running the stock B&N OS, this has worked fine. When I get home and plug in, Calibre sees which books are no longer on the device.
However, using Calibre Companion, when I delete books they still show up in CC and therefore in Calibre as being on the device. If I manually remove the books using Calibre, CC updates correctly. (That is, if I can remember which books to remove!)
So I assume CC has it's own index file. If so, this index file doesn't seem to update on it's own nor is there an option to manually update it. Nor could I find an option in CC to delete the book from there.
I'm not sure if this is a feature request or a bug, but manually babysitting which files are on the device seems to me to be inappropriate for a file management application.
In order to keep calibre's metadata up-to-date and to support grouping and sorting by calibre data, CC has a database of books. You can delete a book from within CC by tapping on the book to open Book Details then selecting "Delete" on the action bar (see screenshot). This will delete the book from the file system and from CC's db.
Regarding the main point of your post: you are correct, deleting the file outside of CC (e.g., with a file manager) does not remove the item from CC's database. We can't depend on "watching" the file system because it is very possible that CC isn't running when the file is deleted. We would need to scan the file system, which is slow. Another reason not to delete the books automatically: it is possible that the files are missing temporarily because the wrong SD card is plugged in or because they were deleted by mistake. For these reasons we made the scan operation on-demand: Settings -> Books with missing files (near the bottom of the options list). Running the scan produces a possibly empty list of books. You can delete the books by opening book details and tapping Delete, you can connect to calibre and resend the books, or you can put the right SD card into the device.
An argument can be made that one should be able to delete in one go all the books that the scan operation finds. We will look at adding that option to the action bar. It is also arguable that this operation should not be in the settings dialog but should be its own line in the menu, making it easier to find. It used to be this way before we added the unified preferences/settings dialog.