lisp/org/org-mks.el

   1 ;;; org-mks.el --- Multi-key-selection for Org-mode
   2
   3 ;; Copyright (C) 2010-2012  Free Software Foundation, Inc.
   4
   5 ;; Author: Carsten Dominik <carsten at orgmode dot org>
   6 ;; Keywords: outlines, hypermedia, calendar, wp
   7 ;; Homepage: http://orgmode.org
   8 ;;
   9 ;; This file is part of GNU Emacs.
  10 ;;
  11 ;; GNU Emacs is free software: you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation, either version 3 of the License, or
  14 ;; (at your option) any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  23 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  24
  25
  26 ;;; Commentary:
  27 ;;
  28
  29 ;;; Code:
  30
  31 (require 'org)
  32 (eval-when-compile
  33   (require 'cl))
  34
  35 (defun org-mks (table title &optional prompt specials)
  36   "Select a member of an alist with multiple keys.
  37 TABLE is the alist which should contain entries where the car is a string.
  38 There should be two types of entries.
  39
  40 1. prefix descriptions like (\"a\" \"Description\")
  41    This indicates that `a' is a prefix key for multi-letter selection, and
  42    that there are entries following with keys like \"ab\", \"ax\"...
  43
  44 2. Selectable members must have more than two elements, with the first
  45    being the string of keys that lead to selecting it, and the second a
  46    short description string of the item.
  47
  48 The command will then make a temporary buffer listing all entries
  49 that can be selected with a single key, and all the single key
  50 prefixes.  When you press the key for a single-letter entry, it is selected.
  51 When you press a prefix key, the commands (and maybe further prefixes)
  52 under this key will be shown and offered for selection.
  53
  54 TITLE will be placed over the selection in the temporary buffer,
  55 PROMPT will be used when prompting for a key.  SPECIAL is an alist with
  56 also (\"key\" \"description\") entries.  When one of these is selection,
  57 only the bare key is returned."
  58   (setq prompt (or prompt "Select: "))
  59   (let (tbl orig-table dkey ddesc des-keys allowed-keys
  60             current prefix rtn re pressed buffer (inhibit-quit t))
  61     (save-window-excursion
  62       (setq buffer (org-switch-to-buffer-other-window "*Org Select*"))
  63       (setq orig-table table)
  64       (catch 'exit
  65         (while t
  66           (erase-buffer)
  67           (insert title "\n\n")
  68           (setq tbl table
  69                 des-keys nil
  70                 allowed-keys nil)
  71           (setq prefix (if current (concat current " ") ""))
  72           (while tbl
  73             (cond
  74              ((and (= 2 (length (car tbl))) (= (length (caar tbl)) 1))
  75               ;; This is a description on this level
  76               (setq dkey (caar tbl) ddesc (cadar tbl))
  77               (pop tbl)
  78               (push dkey des-keys)
  79               (push dkey allowed-keys)
  80               (insert prefix "[" dkey "]" "..." "  " ddesc "..." "\n")
  81               ;; Skip keys which are below this prefix
  82               (setq re (concat "\\`" (regexp-quote dkey)))
  83               (while (and tbl (string-match re (caar tbl))) (pop tbl)))
  84              ((= 2 (length (car tbl)))
  85               ;; Not yet a usable description, skip it
  86               )
  87              (t
  88               ;; usable entry on this level
  89               (insert prefix "[" (caar tbl) "]" "     " (nth 1 (car tbl)) "\n")
  90               (push (caar tbl) allowed-keys)
  91               (pop tbl))))
  92           (when specials
  93             (insert "-------------------------------------------------------------------------------\n")
  94             (let ((sp specials))
  95               (while sp
  96                 (insert (format "[%s]     %s\n"
  97                                 (caar sp) (nth 1 (car sp))))
  98                 (push (caar sp) allowed-keys)
  99                 (pop sp))))
 100           (push "\C-g" allowed-keys)
 101           (goto-char (point-min))
 102           (if (not (pos-visible-in-window-p (point-max)))
 103               (org-fit-window-to-buffer))
 104           (message prompt)
 105           (setq pressed (char-to-string (read-char-exclusive)))
 106           (while (not (member pressed allowed-keys))
 107             (message "Invalid key `%s'" pressed) (sit-for 1)
 108             (message prompt)
 109             (setq pressed (char-to-string (read-char-exclusive))))
 110           (when (equal pressed "\C-g")
 111             (kill-buffer buffer)
 112             (error "Abort"))
 113           (when (and (not (assoc pressed table))
 114                      (not (member pressed des-keys))
 115                      (assoc pressed specials))
 116             (throw 'exit (setq rtn pressed)))
 117           (unless (member pressed des-keys)
 118             (throw 'exit (setq rtn (rassoc (cdr (assoc pressed table))
 119                                            orig-table))))
 120           (setq current (concat current pressed))
 121           (setq table (mapcar
 122                        (lambda (x)
 123                          (if (and (> (length (car x)) 1)
 124                                   (equal (substring (car x) 0 1) pressed))
 125                              (cons (substring (car x) 1) (cdr x))
 126                            nil))
 127                        table))
 128           (setq table (remove nil table)))))
 129     (when buffer (kill-buffer buffer))
 130     rtn))
 131
 132 (provide 'org-mks)
 133
 134 ;;; org-mks.el ends here