Example: Notebook

public class Application : Gtk.Window {
public Application () {
// Prepare Gtk.Window:
this.title = "My Gtk.Notebook";
this.window_position = Gtk.WindowPosition.CENTER;
this.destroy.connect (Gtk.main_quit);
this.set_default_size (400, 400);

// The Notebook:
Gtk.Notebook notebook = new Gtk.Notebook ();
this.add (notebook);

// Tab 1:
Gtk.Label title = new Gtk.Label ("Title 1");
Gtk.Label content = new Gtk.Label ("Content 1");
notebook.append_page (content, title);

// Tab 2:
title = new Gtk.Label ("Title 2");
content = new Gtk.Label ("Content 2");
notebook.append_page (content, title);
}

public static int main (string[] args) {
Gtk.init (ref args);

Application app = new Application ();
app.show_all ();
Gtk.main ();
return 0;
}
}

 valac --pkg gtk+-3.0 Gtk.Notebook.vala

See: