Re: Custom model in gtkada?

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On Thu, 22 Jun 2006 09:16:22 +0200, Emmanuel Briot wrote:

> Dmitry A. Kazakov wrote:
>> I would expect callbacks be primitive operations of a tagged type rather
>> than pointers.
> 
> This is of course a design choice, and you can easily implement a small
> layer on top of GtkAda to do just that.
> The advantage with pointers is that you can add or remove callbacks during
> the life of a widget, which is harder to do with primitive operations where
> you need flags to know whether to react to the event or not. Also you can
> have multiple callbacks on the same signal, which, again, is harder to do
> with primitive operations.

Maybe, though I doubt that events were a right design decision (as a
notification mechanism).

Another point, a list of pointers to subprograms is in no way better than a
list of tagged objects (with primitive subprograms).

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de