From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Stefan Monnier via Users list for the GNU Emacs text editor Newsgroups: gmane.emacs.help Subject: Re: [QUESTION] Add conditional indicator to `mode-line-misc-info' not working Date: Thu, 07 Mar 2024 09:54:58 -0500 Message-ID: References: <65e96d12.170a0220.932f6.0c8f@mx.google.com> Reply-To: Stefan Monnier Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="16202"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) To: help-gnu-emacs@gnu.org Cancel-Lock: sha1:aAI6pj/T4hn19n1m+amJobVtRKY= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Thu Mar 07 15:55:57 2024 Return-path: Envelope-to: geh-help-gnu-emacs@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 1riFA5-00044H-0X for geh-help-gnu-emacs@m.gmane-mx.org; Thu, 07 Mar 2024 15:55:57 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1riF9W-0001rD-HN; Thu, 07 Mar 2024 09:55:22 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1riF9L-0001hM-0Q for help-gnu-emacs@gnu.org; Thu, 07 Mar 2024 09:55:12 -0500 Original-Received: from ciao.gmane.io ([116.202.254.214]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1riF9I-0004Ro-Rr for help-gnu-emacs@gnu.org; Thu, 07 Mar 2024 09:55:10 -0500 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1riF9E-0002lV-QC for help-gnu-emacs@gnu.org; Thu, 07 Mar 2024 15:55:04 +0100 X-Injected-Via-Gmane: http://gmane.org/ Received-SPF: pass client-ip=116.202.254.214; envelope-from=geh-help-gnu-emacs@m.gmane-mx.org; helo=ciao.gmane.io X-Spam_score_int: -16 X-Spam_score: -1.7 X-Spam_bar: - X-Spam_report: (-1.7 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.25, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.help:146050 Archived-At: > #+begin_src emacs-lisp > (add-to-list 'mode-line-misc-info > '(image-mode (:eval (image-size (image-get-display-property) :pixels)))) > #+end_src > > But it's not displaying image info on mode-line when I open an image > with [M-x find-file RET /path/to/image.png RET]. > > I searched GitHub code for `mode-line-misc-info` examples. I don't know > what does the `image-mode` mean in upper code. I know searching the 'net is fun and all, but Emacs was designed before it, so it comes with a manual that can answer those questions even when greed will have finished rendering the internet useless. C-h i m elisp RET m mode line format RET m data RET will get you to the relevant node. > Is it a condition which only evaluate following `(:eval (image-size > ...))` snippet in buffer which major-mode is `image-mode`? Close, but no: it shows it only when the `image-mode` variable is non-nil. IOW it was designed for minor modes rather than major modes. For major modes, you usually use a buffer-local setting instead, e.g. (add-hook 'image-mode-hook (lambda () (setq mode-name `("" ,mode-name (:eval ...))))) I used here a variable that's already used buffer-locally (another is `mode-line-process`), which is less likely to cause surprises than if you make `mode-line-misc-info` buffer-local. Note also that the `:eval` thing should return a string, not a number or a `cons`. > How to correctly add indicator to `mode-line-misc-info`? You could do: (defvar-local my-indicator nil) (unless (memq 'my-indicator mode-line-misc-info) (setq mode-line-misc-info `("" my-indicator . ,mode-line-misc-info))) and then (add-hook 'image-mode-hook (lambda () (setq my-indicator `(:eval ...)))) -- Stefan