Re: drag and drop

[Owen Taylor <otaylor redhat com>]

hubert.fauque@wanadoo.fr writes:

> I have sent three messages to the gtk-devel-list
> but they seem to have disappeared; I don't get them
> back from the list;

Hmmm .. are you subscribed to the list yourself?
Is your subscription address the same as the posting
address? If both of these are true, you might
want to send some mail to listmaster@redhat.com.

> so I resend this message to the gtk-list:
> 
> I have found that the drop on a tree doesn't work well:
> If I call gtk_drag_dest_set on the tree_items, the drop succeeds
> only when it is on the first tree_item, and not when I try
> to drop on the other tree_items; in fact the drop succeeds
> in this case when the cursor is at some distance below the
> tree_item;
> I have traced the problem to gtkdnd.c in the function
> gtk_drag_find_widget; 
> the problem  comes from the fact that the tree
> which is in a tree_item is not drawn inside the tree_item;
> and this function seems to assume that the children of a
> widget are always drawn inside this widget;

That is an accurate assumption as far as GTK+ goes -
the children of a widget _are_ drawn inside this
widget.

So, basically, GtkTree is broken. The only correct
fix is to make it compute its allocations so that
the tree is inside the GtkTreeItem. I do _not_
want to special case GtkTree inside gtkdnd.c.

That GtkTree has issues has been known for a while -
another major issue is that it is limited to
being a total of 32768 pixels high (i.e. - about
2000 rows)  

If you possibly can, you should be using the GtkCTree
instead of the GtkTree. The CTree isn't perfect
itself, but it is better tested and more actively
developed these days. 

Regards,
                                        Owen