Re: Gio::Settings get notified about changes

[Kjell Ahlstedt <kjell ahlstedt bredband net>]

You can't use Glib::ObjectBase::connect_property_changed(). Your 
text-scaling-factor is s settings key, it's not a property in the 
GObject type system. You must use Gio::Settings::signal_changed(). There 
is an example at https://git.gnome.org/browse/glibmm/tree/examples/settings.

The signal_changed() overload that takes a key name as a parameter is 
brand new and so far exists only in the latest unstable version glibmm 
2.45.2. If you use an earlier version, you must use signal_changed() 
without a parameter, and test the key parameter in the signal handler to 
see which value has changed.

Kjell

Den 2015-06-23 23:41, Kasper Peeters skrev:
> I am trying to use Gio::Settings to get notified about changes to a
> particular property value, doing something like
>
>     class X {
>        public:
>           X();  
>        private:
>           Glib::RefPtr<Gio::Settings> settings;
>           void                        handler();
>     }
>
>     X::X()
>        {
>        settings =
>           Gio::Settings::create("org.cinnamon.desktop.interface");
>   
>        settings->connect_property_changed("text-scaling-factor",
>                                sigc::mem_fun(*this, &X::handler));
>        }
>
>     void X::handler()
>        {
>        // do something with changed setting.
>        }
>
> However, the X::handler() is never called when I change the setting.
>
> I did check that if I monitor the setting with
>
>    gsettings monitor org.cinnamon.desktop.interface text-scaling-factor
>
> and make a change using e.g. dconf-editor I can see that the value
> changes.
>
> Any ideas on what I'm doing wrong? Or is there someone with a simple
> Gio::Settings example able to help me out? (Would, incidentally, make a
> good addition to the gtkmm book.) Thanks!
>
> Cheers,
> Kasper