Re: How to implement Gtk::Orientable interface?

[Kjell Ahlstedt <kjellahlstedt gmail com>]

On 10/25/2017 10:40 AM, Tom Schoonjans wrote:

Hi all,


I have a class that derives from Glib::Object that should implement Gtk::Orientable. I thought it would be sufficient to just do:

class MyClass : public MyParentClass, ::Gtk::Orientable {
	public:
	MyClass() : Glib::ObjectBase(“MyClass"), MyParentClass(), Gtk::Orientable() {}
};

Even though this compiles without problems, I do get into trouble at runtime with errors like:

(test1:35777): GLib-GObject-WARNING **: attempting to add an interface (GtkOrientable) to class (gtkmm__CustomObject_MyClass) after class_init

(test1:35777): Gtk-CRITICAL **: gtk_orientable_get_orientation: assertion 'GTK_IS_ORIENTABLE (orientable)' failed

(test1:35777): Gtk-CRITICAL **: gtk_orientable_get_orientation: assertion 'GTK_IS_ORIENTABLE (orientable)' failed


I have tried changing the order of the parent constructors but that doesn’t seem to make a difference.

I would be very grateful for any help!

Thanks in advance and best regards,

Tom

Have you tried this version? I think i'll work,

class MyClass : public Gtk::Orientable, public MyParentClass {
	public:
	MyClass() : Glib::ObjectBase(“MyClass"), Gtk::Orientable(), MyParentClass() {}
};

You have made Gtk::Orientable a private base class by omitting "public". I don't know if that's possible. Anyway, it's important that Gtk::Orientable goes before MyParentClass in the first line. That's what determines in which order the constructors are called.

Kjell