From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Alan Mackenzie Newsgroups: gmane.emacs.devel Subject: Re: Use of `window-system' as a predicate is deprecated. Why? Date: Sat, 9 Jul 2022 13:27:43 +0000 Message-ID: References: <831quu31dh.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="7604"; mail-complaints-to="usenet@ciao.gmane.io" Cc: emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sat Jul 09 15:28:31 2022 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1oAAVa-0001mf-7j for ged-emacs-devel@m.gmane-mx.org; Sat, 09 Jul 2022 15:28:30 +0200 Original-Received: from localhost ([::1]:44174 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oAAVY-0006nr-OI for ged-emacs-devel@m.gmane-mx.org; Sat, 09 Jul 2022 09:28:28 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:47420) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oAAUu-00068B-Tb for emacs-devel@gnu.org; Sat, 09 Jul 2022 09:27:48 -0400 Original-Received: from colin.muc.de ([193.149.48.1]:34998 helo=mail.muc.de) by eggs.gnu.org with smtp (Exim 4.90_1) (envelope-from ) id 1oAAUs-0004S1-P0 for emacs-devel@gnu.org; Sat, 09 Jul 2022 09:27:48 -0400 Original-Received: (qmail 5193 invoked by uid 3782); 9 Jul 2022 13:27:44 -0000 Original-Received: from acm.muc.de (p4fe15f65.dip0.t-ipconnect.de [79.225.95.101]) (using STARTTLS) by colin.muc.de (tmda-ofmipd) with ESMTP; Sat, 09 Jul 2022 15:27:43 +0200 Original-Received: (qmail 7394 invoked by uid 1000); 9 Jul 2022 13:27:43 -0000 Content-Disposition: inline In-Reply-To: <831quu31dh.fsf@gnu.org> X-Submission-Agent: TMDA/1.3.x (Ph3nix) X-Primary-Address: acm@muc.de Received-SPF: pass client-ip=193.149.48.1; envelope-from=acm@muc.de; helo=mail.muc.de X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.io gmane.emacs.devel:291988 Archived-At: Hello, Eli. On Sat, Jul 09, 2022 at 15:40:42 +0300, Eli Zaretskii wrote: > > Date: Sat, 9 Jul 2022 12:22:41 +0000 > > From: Alan Mackenzie > > Do _not_ use `window-system' and `initial-window-system' as predicates > > or boolean flag variables, if you want to write code that works > > differently on text terminals and graphic displays. That is because > > `window-system' is not a good indicator of Emacs capabilities on a > > given display type. Instead, use `display-graphic-p' or any of the > > other `display-*-p' predicates described in Display Feature Testing. > > .. I am amending minibuf.c and wish to know only whether the current > > terminal->focus_frame_hook is validly set. > > The manual entry seems to be to be unnecessarily patronising. It > > insinuates that the only possible "capabilities" a user could be > > interested in are graphic capabilities. > The ELisp reference manual is written for Lisp programmers, not for > people who work on the C sources. :-) > To check whether terminal->focus_frame_hook is set, test it for being > non-NULL. I think I did at one time, and it was set to x_focus_frame, even though I was on a linux tty. But maybe I'm mistaken. Anyway, that doesn't really matter, because .... > More generally, if you want to know whether a frame is on a > window-system, use the FRAME_WINDOW_P macro. This indeed works well, on a linux tty, and in X Windows, both with and without -nw. Thanks! Just as a matter of interest, I think we're nearly there with bug #56305 "29.0.50; 'yes-or-no-p' deselects minibuffer frame". There are just one or two things to clear up with Martin. -- Alan Mackenzie (Nuremberg, Germany).