From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Michael Heerdegen Newsgroups: gmane.emacs.devel Subject: Re: Community improvements to the Emacs Widget Library manual? Date: Thu, 13 Jul 2023 05:30:14 +0200 Message-ID: <87edlcmqt5.fsf@web.de> References: <87o7kh22oc.fsf@cyberscientist.ca> <39814a3e-74d6-d573-761a-f5e107a98871@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="13367"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) To: emacs-devel@gnu.org Cancel-Lock: sha1:j+0r6HIzUFRlHy72tuRDMIpjSQA= Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Thu Jul 13 05:31:24 2023 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 1qJn35-0003KC-Be for ged-emacs-devel@m.gmane-mx.org; Thu, 13 Jul 2023 05:31:23 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qJn2A-0008GB-50; Wed, 12 Jul 2023 23:30:26 -0400 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 1qJn27-0008G1-SP for emacs-devel@gnu.org; Wed, 12 Jul 2023 23:30:23 -0400 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 1qJn26-0004Rs-EI for emacs-devel@gnu.org; Wed, 12 Jul 2023 23:30:23 -0400 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1qJn24-0002Ev-1t for emacs-devel@gnu.org; Thu, 13 Jul 2023 05:30:20 +0200 X-Injected-Via-Gmane: http://gmane.org/ Received-SPF: pass client-ip=116.202.254.214; envelope-from=ged-emacs-devel@m.gmane-mx.org; helo=ciao.gmane.io X-Spam_score_int: -13 X-Spam_score: -1.4 X-Spam_bar: - X-Spam_report: (-1.4 / 5.0 requ) BAYES_00=-1.9, FREEMAIL_FORGED_FROMDOMAIN=0.25, FREEMAIL_FROM=0.001, 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: 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-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.devel:307804 Archived-At: Mauro Aranda writes: > Creation of a widget takes two steps: conversion and creation. > > Conversion means to take a specification of the widget to be created > (type and properties) and convert that specification into another one, > suitable for creating the widget.  So if you want to handle those extra > args in a specific way, or to manipulate the widget before creation, you > need a :convert-widget function, that widget-convert (which is > undocumented in the manual) will make sure to call.  It will call the > most specific :convert-widget function first, and then the > :convert-widget of the parents. This would be a nice paragraph to add to the manual I think. > You can see an example of this in the following code: > > (defun completion--update-styles-options (widget) >   "Function to keep updated the options in > `completion-category-overrides'." >   (let ((lst (mapcar (lambda (x) >                        (list 'const (car x))) >              completion-styles-alist))) >     (widget-put widget :args (mapcar #'widget-convert lst)) >     widget)) > > (defconst completion--styles-type >   `(repeat :tag "insert a new menu to add more styles" >            (choice :convert-widget completion--update-styles-options))) > > Here completion--styles-type holds a type definition for a defcustom, > and the idea is to make the choices available build dynamically. > Without a custom :convert-widget function, the :args would've been > defined in a static way as soon as the type gets defined.  So we use a > :convert-widget function that builds the choices, and puts them into the > :args property, as required by the choice widget.  Then, when creating > it, all the choices in :args show up in the buffer. And this is a nice example for it! BTW, one thing I often wondered about (I think it's missing in the manual): one often sees code using list values like `(widget-type :keyword1 ,(lambda ...) ...) What is that? Already a widget? A widget definition? What functions accept such list values, and how do I create a real widget using such values? Michael.