[pygtk] Re: Re: Cannot subclass gtk.Widget

[John Dennis]

On Fri, 2007-03-09 at 10:38 -0500, John Dennis wrote:
> On Fri, 2007-03-09 at 08:10 -0700, Jeffrey Barish wrote:
> > Gustavo J. A. M. Carneiro wrote:
> > 
> > > Another, more complex, example can be found here:
> > > http://telecom.inescporto.pt/~gjc/higcontainer/higcontainer.py
> > 
> > Thanks to everyone for the examples.  Is there documentation anywhere on the
> > do_ methods that they all contain?  I guess that when a Widget receives a
> > size_request call, for example, it calls do_size_request on its children.
> 
> My understanding, albeit gleaned only from example code and
> experimentation is widget subclassing in pygtk works by the following
> method. Instead of overriding a method by creating a new method in the
> subclass with the same name as is the normal method of subclass override
> in OO languages pygtk appears to operate this way: The name of the
> method is prefixed with 'do_' and a method look up is performed on that
> name in the subclass, if the do_xxxx method is found it is invoked as
> the overridden method. If the override mechanism does not work this way
> I'd love to know what actually is going on. I'm also curious as to why
> pygtk seems to have this peculiar and undocumented subclassing form.
> 
> To the best of my knowledge the 'do_' prefix method of subclassing is
> totally undocumented in pygtk other than it appears in the example code.
> I searched for hours looking for a clear statement of the subclassing
> behavior and I never found it. To my mind this is a serious
> documentation omission.

Could it be that 'do_' method naming is not subclassing but rather
auto-magic signal connecting via method naming convention? Either way, I
never did find any documentation on it.
-- 
John Dennis <jdennis at redhat.com>