> Audiobooks often consists of many tracks of several CDs, so that you have to organize them in one long playlist
Why aren't you using the 'audiobooks' node?
When you drag tracks to this node, the following setting is automatically applied:
right-click a track -> edit -> settings tab -> remember playback position.
You could use a playlist for the above, but you'd have to enable the 'playback position' setting manually yourself.
I find it's nice to have books separate from all your music, so that's another reason I use the audio books node.
In fact, once I've downloaded a full set of podcasts, I archive them in the audiobook node too.
To see where you are up to in a book, you can expose the 'playcount' column.
So you will see something like this:
playcount
chapter 1 1
chapter 2 1
chapter 3 0
chapter 4 0
This tells us that you have listened to chapter 2, but have not listened to chapter 3 yet.
When you play ch3, because of 'remember playback position', it will continue from where you left it.
You may need to adjust the playcount settings in:
preferences -> now playing -> playback -> playcount
Eg. more than 99% of track played or 0 seconds
... would hopefully only increment the playcount once you've listened to an entire track.
Although you might have to put 1000000 seconds to 'disable' that part, rather than zero seconds.
If you don't like the playcount method, you can manually mark read chapters by exposing the 'tickbox' column, and clicking next to the track.
This method would work in the playlist too.
Or expose the 'love' column and click in that instead.
Or use the rating column - one star means 'read'.
Or you could take a different approach altogether and use the 'bookmarks' node to manually mark where you're up to.
Just throwing around some existing ideas and options, not to detract from your initial wish.