Re: Builder derived widgets with properties -- error validate_and_install_class_property: assertion 'class->set_property != NULL' failed

[Dan Lo Forte <dan coastblue net>]

Kjell,

That worked! Thanks!

Dan

On 8/30/22 08:06, Kjell Ahlstedt wrote:
> Den 2022-08-29 kl. 23:37, skrev Dan Lo Forte:
> > I have a glade file from which I load a derived widget that has a 
> > Glib::Property.  When I load the main window, I get the following error:
> >
> > ```
> >
> > GLib-GObject-CRITICAL **: validate_and_install_class_property: 
> > assertion 'class->set_property != NULL' failed
> >
> > ```
> >
> > I have created a simplified example, as per this page: 
> > https://developer-old.gnome.org/gtkmm-tutorial/stable/sec-builder-using-derived-widgets.html.en, 
> > using a derived Gtk::Button and still see the error.
> Your simplified example is very similar to the example at 
> https://gitlab.gnome.org/GNOME/gtkmm-documentation/-/tree/gtkmm-3-24/examples/book/builder/derived, 
> which does not print an error message. There is a significant 
> difference in the glade file (glade_str). You shall change GtkButton 
> to gtkmm__CustomObject_DerivedButtonProp, the Gtype name of your 
> button class.