Re: [wxhaskell-users] TreeCtrl Drag and Drop

[<wxh...@al...>]

> Well, when I tried your example, it first crashed on me! As I am using
> a debug version, I quickly found out that the wxWidget code asserts that
> an image list is present when dragging -- even when just using text
> labels :-(
> I just wonder whether that might cause you trouble. When I added images
> (using
> the filebrowse example images) everything worked -- of course, drags were
> vetoed
> so, nothing would happen.

Hmm, doesn't crash on me.  But I went ahead and added the images, but
nothing changed.  Note that I said try with and without the "veto",
because I'm not sure it should really even be "veto".  In the C++
version, you have to explicitly allow the dragging, because the default
is not to drag, as evidenced in the wxWidgets sample program:

void MyTreeCtrl::OnBeginDrag(wxTreeEvent& event)
{
    // need to explicitly allow drag
    if ( event.GetItem() != GetRootItem() )
    {
        m_draggedItem = event.GetItem();
 
        wxLogMessage(wxT("OnBeginDrag: started dragging %s"),
                     GetItemText(m_draggedItem).c_str());
 
        event.Allow();
    }
    else
    {
        wxLogMessage(wxT("OnBeginDrag: this item can't be dragged."));
    }
}
 
That's why I wasn't sure if the "veto" wasn't really this "event.Allow()"
call.  But it doesn't matter, because I try it both ways and neither way
works.  Any ideas?

Thanks.