[cl-gtk2-devel] GBoxed, signals, and dnd

[Kalyanov Dmitry]

On Mon, 2011-08-22 at 18:18 -0500, Ryan Pavlik wrote:
> I'm currently working on implementing the calls necessary for DND on
> the gtk side.  For the most part, this has been relatively
> straightforward; I can receive drop data and initiate drags.
> 
> However, the critical part for initiated drags is setting
> selection-data in the drag-data-get signal handler.  This requires you
> to alter the passed selection-data in response; however, the changes
> don't appear to be copied out.  How can I accomplish this?
> 
> It appears that glib-defcallback is defined for a related purpose, but
> this doesn't seem useful in conjunction with signal handlers.
> 
> thanks,
> 

I admit that mapping of GBoxed types is not well thought out - it does
not fully capture semantics of C structures.

The easiest way to accomplish this would be to add ability to override
parsing of signal arguments (in gobject.signals.lisp, relevant functions
are LISP-SIGNAL-HANDLER-CLOSURE-MARSHAL, PARSE-CLOSURE-ARGUMENTS) and
use it to parse relevant arguments of signals as just pointers.