On Tue, 2013-09-03 at 21:20 +0100, Chris Vine wrote: > On Tue, 03 Sep 2013 09:40:19 +0200 > Murray Cumming <murr...@murrayc.com> wrote: > > On Mon, 2013-09-02 at 16:13 +0200, Krzysztof Kosiński wrote: > > > 2013/9/2 Kjell Ahlstedt <kjell.ahlst...@bredband.net>: > > > > Objects of classes that derive from Gtk::Object are not put in > > > > Glib::RefPtr<>s. I'm not sure why. > > > > > > I'm also a little confused by this but it probably has something to > > > do with Gtk::manage(). > > > > GtkWidgets don't use simple reference counting in the GTK+ C API. They > > can be destroyed at any time regardless of the reference count. So we > > can't use RefPtr with them easily. > > That is not really true. widgets are always (and only) destroyed when > their sunk reference count reaches 0,
Calling gtk_widget_destroy() will destroy a widget. Containers destroy their child widgets by default in GTK+ with C. > and incrementing the reference > count before removing a widget from a container is how you move them > between containers. Yes, that is necessary, though we do that for you in gtkmm. > There is no problem with holding a non-top level > widget by RefPtr provided you call g_object_ref() on the C object > first, which is inconvenient with gtkmm and leaves the opportunity to > forget to do so. So it is inadvisable. I believe that this would lead to having RefPtrs pointing to invalid (destroyed) GtkWidget instances. I suppose you could improve this by letting the RefPtr know when the widget is going to be destroyed, allowing us to check the RefPtr at runtime, but I don't think you could stop the GtkWidget destruction, I don't think GTK+ would want you to, and I don't think it would be a nice C++ API. > With top level windows it would be highly confusing to take your own > reference in this way. You expect a top level window to disappear when > you call gtk_widget_destroy() on it to drop GTK+'s top level reference, > not hang around. -- murr...@murrayc.com www.murrayc.com www.openismus.com _______________________________________________ gtkmm-list mailing list gtkmm-list@gnome.org https://mail.gnome.org/mailman/listinfo/gtkmm-list
