By default, should probably use the Qt standard method for storing application data in a cross platform manner.

See QDesktopServices - should DICOM data be in DataLocation or in DocumentsLocation?

We recently gave a Slicer training to about 10 students and this was a major inconvenience. Users didn't understand why the popup is displayed, some people just wanted to get rid of it and were very pissed because hitting cancel didn't do anything (the popup came back, couldn't close the popup in any way, couldn't even close Slicer), while other thought that they should give the location of their DICOM files (also very bad, imported DICOM files were mixed with input DICOM files).

So, it's important to initialize the DICOM DB location by default. By default the the database could be in the same folder as the Slicer.ini file (maybe in a DicomDatabase subfolder).

Andras: this describes our experience at RSNA pretty well ...

I think this belongs in the Documents directory. I don't like the idea of putting it into a hidden directory like .config or .local since it can be a fairly large, and actually important directory that shouldn't be hidden. Particularly since Ron requested that Copy On Import be the new default setting.

I agree about the 'can't cancel' issue - I'll see about fixing that.

I agree with Steve that Documents is a better location. I think this is the location where OxiriX puts its database directory by the way.

With this a default location is selected to start up.

http://viewvc.slicer.org/viewvc.cgi/Slicer4?view=revision&revision=21524