fxruby users - Mar 2007 - new DND idea

Hi there.  Some of you may remember that I was having problems with 
DND.  I solved that problem using YAML.  However, I have run into new 
problems because YAML creates a new instance of the object, exactly 
equal to the old one, but nonetheless, a new object in a different 
memory location.  Instead of doing that, I wish to simply pass the 
actual reference, the memory location, of the object.  How would I do 
that?  For example, if "card" in this case was a reference to on
object
at 0x0000001 (contrived, yes):

imageView.connect(SEL_DND_REQUEST) do |sender, sel, event|
         if event.target == @image_drag_type
                  imageView.setDNDData(FROM_DRAGNDROP, @image_drag_type,
                       Fox.fxencodeStringData(YAML.dump(card)))
                  data_sent = true
         end
end


Instead of encoding the YAML.dump, I would encode what?  And on the 
otherside, I would decode and then what?

Thanks,
Raj Sahae

On 3/19/07, Raj Sahae <rajsahae at gmail.com> wrote:
> Hi there.  Some of you may remember that I was having problems with
> DND.  I solved that problem using YAML.  However, I have run into new
> problems because YAML creates a new instance of the object, exactly
> equal to the old one, but nonetheless, a new object in a different
> memory location.
Right, and this is a good thing if you''re dragging the object to
another instance of the application that doesn''t share the same memory
space.
> Instead of doing that, I wish to simply pass the
> actual reference, the memory location, of the object.  How would I do
> that?  For example, if "card" in this case was a reference to on
object
> at 0x0000001 (contrived, yes):
<snip>
> Instead of encoding the YAML.dump, I would encode what?  And on the
> otherside, I would decode and then what?
It sounds like you''re assuming that it''s always going to be a
"local"
drag and drop (i.e an object is dragged and dropped within the same
application instance). In that case, the simplest solution might be to
just use the object''s id as its encoding:

    setDNDData(FROM_DRAGNDROP, @image_drag_type, card.__id__.to_s)

and then decode it using ObjectSpace#_id2ref:

    data = getDNDData(FROM_DRAGNDROP, @image_drag_type)
    card = ObjectSpace._id2ref(data.to_i)

Hope this helps,

Lyle