From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,FREEMAIL_FROM, WEIRD_PORT autolearn=unavailable autolearn_force=no version=3.4.4 X-Received: by 10.98.33.209 with SMTP id o78mr19455507pfj.6.1454883105404; Sun, 07 Feb 2016 14:11:45 -0800 (PST) X-Received: by 10.182.227.200 with SMTP id sc8mr396451obc.0.1454883105363; Sun, 07 Feb 2016 14:11:45 -0800 (PST) Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!news.eternal-september.org!mx02.eternal-september.org!feeder.eternal-september.org!news.glorb.com!o2no3009131iga.0!news-out.google.com!kr2ni9547igb.0!nntp.google.com!hb3no1898816igb.0!postnews.google.com!glegroupsg2000goo.googlegroups.com!not-for-mail Newsgroups: comp.lang.ada Date: Sun, 7 Feb 2016 14:11:45 -0800 (PST) In-Reply-To: Complaints-To: groups-abuse@google.com Injection-Info: glegroupsg2000goo.googlegroups.com; posting-host=2601:18f:900:8350:ba86:87ff:fed6:5907; posting-account=AvekzAoAAABj-TclKcOWQmXwA49MFPGX NNTP-Posting-Host: 2601:18f:900:8350:ba86:87ff:fed6:5907 References: <0528d7a8-773d-44b0-8f0a-e9aa48867443@googlegroups.com> <8778e70b-81e1-4dcc-8ecb-8bcaceb74b57@googlegroups.com> User-Agent: G2/1.0 MIME-Version: 1.0 Message-ID: Subject: Re: I do not understand this error... From: John Smith Injection-Date: Sun, 07 Feb 2016 22:11:45 +0000 Content-Type: text/plain; charset=ISO-8859-1 Xref: news.eternal-september.org comp.lang.ada:29411 Date: 2016-02-07T14:11:45-08:00 List-Id: Hello Dmitry, What is Gtk.Missed? That does not seem to exist according to the docs: http://docs.adacore.com/gtkada-docs/gtkada_rm/gtkada_rm/ On Sunday, February 7, 2016 at 3:23:59 AM UTC-5, Dmitry A. Kazakov wrote: > On 2016-02-07 01:34, John Smith wrote: > > The the following example is wrong: > > http://rosettacode.org/wiki/Hello_world/Graphical#Ada > > > > If so, then how would you fix this? > > > > On Saturday, February 6, 2016 at 6:47:49 PM UTC-5, Jeffrey R. Carter wrote: > >> On 02/06/2016 03:55 PM, John Smith wrote: > >>> > >>> gtk_test.adb:16:04: instantiation error at gtk-handlers.ads:1039 > >>> gtk_test.adb:16:04: subprogram must not be deeper than access type > >>> gtk_test.adb:17:04: instantiation error at gtk-handlers.ads:437 > >>> gtk_test.adb:17:04: subprogram must not be deeper than access type > >> > >> This an accessibility check. It means that it's possible for an > >> access-to-subprogram value to be copied into a variable which has longer life > >> than the subprogram. This is not allowed by the language. > > Generic packages from Gtk.Handlers cannot be instantiated in the main > procedure, due to accessibility check, as Jeffrey wrote. > > To resolve this move instantiations Handlers and Return_Handles into a > separate [library level] package and use this package in the main procedure. > > In GtkAda contributions there are pre-instantiated handlers to deal with > gtk program exit. A working example will look like: > -------------------------------------------- > with Gtk.Label; use Gtk.Label; > with Gtk.Window; use Gtk.Window; > > with Gtk.Main; > with Gtk.Missed; > > procedure gtk_test is > Window : Gtk_Window; > Label : Gtk_Label; > begin > Gtk.Main.Init; > Gtk.Window.Gtk_New (Window); > Window.On_Delete_Event (Gtk.Missed.Delete_Event_Handler'Access); > Window.On_Destroy (Gtk.Missed.Destroy_Handler'Access); > Gtk_New (Label, "Goodbye, World!"); > Window.Add (Label); > Window.Show_All; > Gtk.Main.Main; > end gtk_test; > ----------------------------------------------- > http://www.dmitry-kazakov.de/ada/gtkada_contributions.htm > > -- > Regards, > Dmitry A. Kazakov > http://www.dmitry-kazakov.de