From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: GtkAda : Trying to derive a widget
Date: Fri, 9 Apr 2021 00:27:26 +0200 [thread overview]
Message-ID: <s4o00c$sne$1@gioia.aioe.org> (raw)
In-Reply-To: 606f5938$0$27421$426a74cc@news.free.fr
On 2021-04-08 21:27, DrPi wrote:
> I'm trying to create a GtkAda widget derived from a standard widget.
>
> -- debug_panel.ads
> with Gtk.Scrolled_Window; use Gtk.Scrolled_Window;
> with Gtk.Text_View; use Gtk.Text_View;
>
> package Debug_Panel is
>
> type Debug_Panel_Record is new Gtk_Scrolled_Window_Record with private;
> type Debug_Panel is access all Debug_Panel_Record'Class;
>
>
> procedure Gtk_New (Panel : in out Debug_Panel);
> procedure Initialize (Panel : not null access Debug_Panel_Record'Class);
>
> private
>
> type Debug_Panel_Record is new Gtk_Scrolled_Window_Record with record
> Text : Gtk_Text_View;
> end record;
>
> end Debug_Panel;
>
>
> -- debug_panel.adb
> package body Debug_Panel is
>
> procedure Gtk_New (Panel : in out Debug_Panel) is
> begin
> Panel := new Debug_Panel_Record;
> Initialize (Panel);
Debug_Panel.Initialize (Panel);
Another way would be to remove "use Gtk.Scrolled_Window" and declare as
type Debug_Panel_Record is
new Gtk.Scrolled_Window.Gtk_Scrolled_Window_Record with private;
Without "use" Initialize is unambiguous.
P.S. When you create new widget it is better to use a more general
ancestor hiding insufficient details, e.g.
type Debug_Panel_Record is
new Gtk.Widget.Gtk_Widget_Record with private;
...
private
type Debug_Panel_Record is
new Gtk.Scrolled_Window.Gtk_Scrolled_Window_Record with
record
...
end record;
This makes the code less fragile if you later decide to choose another
container widget for the base.
--
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de
next prev parent reply other threads:[~2021-04-08 22:27 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-08 19:27 GtkAda : Trying to derive a widget DrPi
2021-04-08 22:27 ` Dmitry A. Kazakov [this message]
2021-04-09 5:28 ` DrPi
2021-04-09 6:12 ` J-P. Rosen
2021-04-09 11:32 ` DrPi
2021-04-09 6:18 ` Dmitry A. Kazakov
2021-04-09 11:42 ` DrPi
2021-04-09 12:23 ` Dmitry A. Kazakov
2021-04-09 13:37 ` DrPi
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