Re: Binding Variables to Widgets

[Nik Ogura <nogura uma-mn com>]

On Thu, 2007-01-04 at 09:12 +0000, Emmanuele Bassi wrote:
> On Wed, 2007-01-03 at 23:12 -0600, Nik Ogura wrote:
> > Forgive my noobishness, I'm coming from a Perl/Tk background.  
> >
> > In Perl/Tk you can easily bind a variable to a widget, so that any
> > changes to the widget text are automatically changed in the bound
> > variable.
> >
> > Is this sort of thing possible in Gtk2-perl?  Or am I stuck doing
> > $widget->set_text and $widget->get_text calls to do the same?
>
> you want Glib::Object::tie_preferences:
>
>   $object->tie_properties ($all=FALSE)
>
>       * $all (boolean) if FALSE (or omitted) tie only properties for this
>       objectâs class, if TRUE tie the properties of this and all parent
>       classes.
>
>       A special method avaiable to Glib::Object derivatives, it uses
>       perlâs tie facilities to associate hash keys with the properties of
>       the object. For example:
>       
>         $button->tie_properties;
>         # equivalent to $button->set (label => âHello Worldâ);
>         $button->{label} = âHello Worldâ;
>         print "the label is: ".$button->{label}."\n";
>
>       [...]
>               -- from Glib::Object perldoc page
>
> obviously, you really want to be sure that you don't end up adding a key
> named 'text' to your Gtk2::Entry object, or you'd end up with a nasty
> loop.
>
> in any case, if you want to update a variable in sync with the changes,
> just attach a callback to the Gtk2::Entry 'changed' signal and update
> the variable there: it's called 'event-driven programming' for a reason,
> you know. ;-)
>
> ciao,
>  Emmanuele.

That'll do it.  Thanks a bunch.
-- 


-Nik