org-tag-eldoc.el

   1 ;;; org-tag-eldoc.el --- Display tag explanation in Eldoc -*- lexical-binding: t; -*-
   2 ;; -*- coding: utf-8 -*-
   3
   4 ;; Authors: stardiviner <numbchild@gmail.com>
   5 ;; Package-Requires: ((emacs "26.1") (request "0.3.3"))
   6 ;; Version: 0.1.0
   7 ;; Keywords: org
   8 ;; Homepage: https://repo.or.cz/org-tag-eldoc.git
   9
  10 ;; Copyright (C) 2024-2025 Christopher M. Miles, all rights reserved.
  11 ;;
  12 ;; org-tag-eldoc is free software; you can redistribute it and/or modify it
  13 ;; under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation; either version 3, or (at your option)
  15 ;; any later version.
  16 ;;
  17 ;; org-tag-eldoc is distributed in the hope that it will be useful, but WITHOUT
  18 ;; ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  19 ;; or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
  20 ;; License for more details.
  21 ;;
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
  24
  25 ;;; Commentary:
  26
  27 ;;; Display tag explanation in Eldoc when point on tag.
  28
  29 ;;; Code:
  30 \f
  31 (require 'org)
  32 (require 'org-tag-eldoc-database)
  33 (require 'org-tag-eldoc-pixiv-encyclopedia)
  34 (require 'org-tag-eldoc-wikipedia)
  35
  36 (defcustom org-tag-eldoc-tag-explanation-functions
  37   '(org-tag-eldoc-pixiv-encyclopedia-query
  38     org-tag-eldoc-wikipedia-query)
  39   "A list of functions to be executed for query tag explanation."
  40   :type 'list
  41   :safe #'listp
  42   :group 'org-tags)
  43
  44 (defcustom org-tag-eldoc-request-proxy
  45   (or url-proxy-services
  46       '(("http"  . "127.0.0.1:7890")
  47         ("https" . "127.0.0.1:7890")))
  48   "The proxy services inherited from `url-proxy-services'."
  49   :type 'alist
  50   :group 'org-tags)
  51
  52 (defcustom org-tag-eldoc-tag-explanations-alist
  53   '(("Linux" . "Linux (/ˈlɪnʊks/ LIN-uuks) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds.")
  54     ("Emacs" . "Emacs /ˈiːmæks/ ⓘ, originally named EMACS (an acronym for \"Editor Macros\"), is a family of text editors that are characterized by their extensibility. The manual for the most widely used variant, GNU Emacs, describes it as \"the extensible, customizable, self-documenting, real-time display editor\". Development of the first Emacs began in the mid-1970s, and work on GNU Emacs, directly descended from the original, is ongoing; its latest version is 29.2, released January 2024.")
  55     ("GNU" . "GNU (/ɡnuː/ ⓘ) is an extensive collection of free software (385 packages as of September 2023), which can be used as an operating system or can be used in parts with other operating systems. The use of the completed GNU tools led to the family of operating systems popularly known as Linux. Most of GNU is licensed under the GNU Project's own General Public License (GPL)."))
  56   "Alist of cons cell with tag and explanation."
  57   :type 'alist
  58   :safe #'listp
  59   :group 'org-tags)
  60
  61 (defvar org-tag-eldoc--explanation nil
  62   "A private variable to store the function internal variable `explanation'.")
  63
  64 (defun org-tag-eldoc-tag-explanation (&optional tag)
  65   "Display tag explanation in Eldoc when point on TAG."
  66   (let ((tag (or tag (buffer-substring-no-properties (thing-at-point 'symbol)))))
  67     (if-let ((explanation (cdr (assoc tag org-tag-eldoc-tag-explanations-alist))))
  68         explanation
  69       (let ((explanation (seq-some
  70                           (lambda (f)
  71                             ;; reset `org-tag-eldoc--explanation' to avoid bellowing `seq-some' chaos.
  72                             (setq org-tag-eldoc--explanation nil)
  73                             (apply f (list tag))
  74                             (unless (string-equal org-tag-eldoc--explanation "nil")
  75                               org-tag-eldoc--explanation))
  76                           org-tag-eldoc-tag-explanation-functions)))
  77         ;; cache already queried result explanation into `org-tag-eldoc-tag-explanations-alist'.
  78         (when explanation
  79           (add-to-list 'org-tag-eldoc-tag-explanations-alist (cons tag explanation)))))))
  80
  81 (defun org-tag-eldoc-function (&rest args)
  82   "The eldoc function to be added into `eldoc-documentation-functions' with ARGS."
  83   ;; NOTE: `org-element-at-point' return `headline' instead of `tags.' Need Org mode to implement it.
  84   ;; Use `thing-at-point' to workaround the missing `tags' syntax element node in `org-element-at-point' / `org-context'.
  85   (let ((tag (thing-at-point 'symbol))
  86         (tags (org-get-tags nil 'local)))
  87     (when (member tag tags) (org-tag-eldoc-tag-explanation tag))))
  88
  89 ;;; `eldoc-documentation-function', `eldoc-documentation-functions'
  90 ;;;###autoload
  91 (defun org-tag-eldoc-setup ()
  92   "Setup `eldoc-documentation-functions'."
  93   (add-hook 'eldoc-documentation-functions #'org-tag-eldoc-function -10 t))
  94
  95 (add-hook 'org-mode-hook #'org-tag-eldoc-setup)
  96
  97 ;;; TODO: Add mouse hover popup info support.
  98
  99
 100 \f
 101
 102 (provide 'org-tag-eldoc)
 103
 104 ;;; org-tag-eldoc.el ends here