Drag and drop, inter-widget

[John Coppens <john jcoppens com>]

Hello guys,

I've got DnD actually working, between a GtkTreeView and a GtkLayout. I'm using it
to make a scheduler, where the TreeView has the classes to be scheduled, and the
Layout is the actual grid.

Though this works, I can't draw the correct size of the class period in the
layout till I drop the wares, which is when the data exchange takes place. Is there
some way to have a data exchange earlier? Hopefully before the move_over event
starts happening - so I can draw the box with the correct size. 

Of course it would be possible to do a parallel mechanism (say save a copy of the data 
from the treeview as global info) but I'd rather use the DnD mechanism, as this would 
work inter-program too.

John