This file is ment to help people get started hacking on digiKam. It will get 
you up to speed on a couple of structures used. We only started to document
just before digiKam 0.8, so don't expect to much, but whenever you hack some
please update this file as well.

scanlib
Scanlib is a library that takes care of scanning the filesystem for new files
and adds them in the database and checking for missing info in the database so
that it can be included: if date is empty, it adds the exif or modification 
date (in that order) and the comment to database. If the file is not present 
in the database, make sure to add the file to the database and insert the date 
and comments.

pixmapmanager
Since there are date based folders, the number of pixmaps which could be
kept in memory could potentially become too large. The pixmapmanager 
maintains a fixed size cache of thumbnails and loads pixmaps on demand.