org-buffer-todos.el

   1 ;;; org-buffer-todos.el --- Show Org buffer local todo tasks number. -*- lexical-binding: t; -*-
   2 ;; -*- coding: utf-8 -*-
   3
   4 ;; Copyright (C) 2020-2021 Free Software Foundation, Inc.
   5
   6 ;; Authors: stardiviner <numbchild@gmail.com>
   7 ;; Package-Requires: ((emacs "26.1"))
   8 ;; Version: 0.1
   9 ;; Keywords: org
  10 ;; Homepage:
  11
  12 ;; org-buffer-todos 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-buffer-todos 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 ;;
  23 ;; You should have received a copy of the GNU General Public License
  24 ;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
  25
  26 ;;; Commentary:
  27
  28 ;;; Usage:
  29 ;;;
  30 ;;; (add-hook 'org-mode-hook #'org-buffer-todos-mode)
  31
  32 ;;; Code:
  33 \f
  34 (require 'org-element)
  35
  36 (defgroup org-buffer-todos nil
  37   "The customization group of package org-buffer-todos."
  38   :prefix "org-buffer-todos-"
  39   :group 'org)
  40
  41 (defcustom org-buffer-todos-warning nil
  42   "Whether display warning message about `org-buffer-todos-mode'."
  43   :type 'boolean
  44   :safe #'booleanp
  45   :group 'org-buffer-todos)
  46
  47 ;;; Use a variable for `after-save-hook' updating instead of `mode-line-misc-info' instant `:eval'.
  48 (defvar org-buffer-todos-counter nil
  49   "The number of Org buffer local todo tasks counter.")
  50
  51 (put 'org-buffer-todos-counter 'risky-local-variable t)
  52
  53 (defun org-buffer-todos--buffer-big-p ()
  54   "Detect whether current Org buffer is big?"
  55   (> (buffer-size) 100000))
  56
  57 (defun org-buffer-todos-counter ()
  58   "Return tasks counting number in current org-mode buffer."
  59   (when (eq major-mode 'org-mode)
  60     (with-current-buffer (current-buffer)
  61       (let ((headline-todos))
  62         (org-element-map (org-element-parse-buffer) 'headline
  63           (lambda (node)
  64             (let ((headline node))      ; `node' is `headline' like `org-element-context'.
  65               (when (member (org-element-property :todo-keyword headline)
  66                             (or org-todo-keywords-for-agenda
  67                                 (mapcar 'car org-todo-keyword-faces)))
  68                 (let ((headline-title (org-element-property :title headline)))
  69                   (push headline-title headline-todos))))))
  70         (seq-count #'identity headline-todos)))))
  71
  72 (defvar org-buffer-todos-mode-lighter nil
  73   "The `org-buffer-todos-mode' minor-mode mode-line lighter.")
  74
  75 (put 'org-buffer-todos-mode-lighter 'risky-local-variable t)
  76
  77 (defun org-buffer-todos-counter--mode-line-format ()
  78   "Show tasks counting number in a mode-line format."
  79   (let ((org-buffer-todos-counter (org-buffer-todos-counter)))
  80     (when (and (eq major-mode 'org-mode)
  81                (bound-and-true-p org-buffer-todos-counter)
  82                (> org-buffer-todos-counter 0))
  83       (setq org-buffer-todos-mode-lighter
  84             (format " [Todos: %s]" org-buffer-todos-counter)))))
  85
  86 (defun org-buffer-todos-counter--mode-line-update ()
  87   "Update org-mode buffer local tasks counting number in mode-line."
  88   (setq-local org-buffer-todos-counter (org-buffer-todos-counter))
  89   (setq-local org-buffer-todos-mode-lighter (org-buffer-todos-counter--mode-line-format))
  90   ;; (add-to-list 'mode-line-misc-info '(:eval (org-buffer-todos-counter--mode-line-format)))
  91   )
  92
  93 (defun org-buffer-todos-mode--enable ()
  94   "Enable `org-buffer-todos-mode'"
  95   ;; Hook updater function on `after-save-hook'.
  96   (add-hook 'after-save-hook #'org-buffer-todos-counter--mode-line-update nil 'local)
  97   ;; (add-to-list 'mode-line-misc-info
  98   ;;              '(org-buffer-todos-mode (:eval org-buffer-todos-mode-lighter)))
  99   )
 100
 101 (defun org-buffer-todos-mode--disable ()
 102   "Disable `org-buffer-todos-mode'"
 103   (remove-hook 'after-save-hook #'org-buffer-todos-counter--mode-line-update 'local)
 104   ;; (setq mode-line-misc-info
 105   ;;       (delete '(org-buffer-todos-mode (:eval org-buffer-todos-mode-lighter)) mode-line-misc-info))
 106   )
 107
 108 (define-minor-mode org-buffer-todos-mode
 109   "Show Org buffer local todo tasks number in mode-line."
 110   :init-value nil
 111   :lighter org-buffer-todos-mode-lighter ; The mode-line lighter shows string.
 112   :group 'org-buffer-todos
 113   (if org-buffer-todos-mode
 114       (if (org-buffer-todos--buffer-big-p)
 115           (progn
 116             (when org-buffer-todos-warning
 117               (message "[org-buffer-todos] Not enabled in big Org file %s in size: %s"
 118                        (buffer-name) (file-size-human-readable (buffer-size))))
 119             (setq-local org-buffer-todos-mode-lighter nil))
 120         (org-buffer-todos-mode--enable))
 121     (org-buffer-todos-mode--disable)))
 122
 123 \f
 124
 125 (provide 'org-buffer-todos)
 126
 127 ;;; org-buffer-todos.el ends here