Having done all this work, it is probably
discouraging to note that drag and drop has already been
completely integrated into the
QMultiLineEdit class. This means that our
work was quite superfluous, though hopefully instructive.
I have only touched upon the fringes of
this subject. If you want to create your own datatypes in order
to drag and drop complex objects (for instance animation cells,
or three-dimensional CAD drawings, or perhaps complete Python
object hierarchies), then you must implement new Mime types.
This goes way beyond the scope of this book; I suggest you first
read the Qt online documentation on the subject, and then start
experimenting.