lisp/erc/erc-fill.el

   1 ;;; erc-fill.el --- Filling IRC messages in various ways
   2
   3 ;; Copyright (C) 2001-2004, 2006-2015 Free Software Foundation, Inc.
   4
   5 ;; Author: Andreas Fuchs <asf@void.at>
   6 ;;         Mario Lang <mlang@delysid.org>
   7 ;; Maintainer: emacs-devel@gnu.org
   8 ;; URL: http://www.emacswiki.org/cgi-bin/wiki.pl?ErcFilling
   9
  10 ;; This file is part of GNU Emacs.
  11
  12 ;; GNU Emacs is free software: you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation, either version 3 of the License, or
  15 ;; (at your option) any later version.
  16
  17 ;; GNU Emacs is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public 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 <http://www.gnu.org/licenses/>.
  24
  25 ;;; Commentary:
  26
  27 ;; This package implements filling of messages sent and received.  Use
  28 ;; `erc-fill-mode' to switch it on.  Customize `erc-fill-function' to
  29 ;; change the style.
  30
  31 ;;; Code:
  32
  33 (require 'erc)
  34 (require 'erc-stamp); for the timestamp stuff
  35
  36 (defgroup erc-fill nil
  37   "Filling means to reformat long lines in different ways."
  38   :group 'erc)
  39
  40 ;;;###autoload (autoload 'erc-fill-mode "erc-fill" nil t)
  41 (erc-define-minor-mode erc-fill-mode
  42   "Toggle ERC fill mode.
  43 With a prefix argument ARG, enable ERC fill mode if ARG is
  44 positive, and disable it otherwise.  If called from Lisp, enable
  45 the mode if ARG is omitted or nil.
  46
  47 ERC fill mode is a global minor mode.  When enabled, messages in
  48 the channel buffers are filled."
  49   nil nil nil
  50   :global t :group 'erc-fill
  51   (if erc-fill-mode
  52       (erc-fill-enable)
  53     (erc-fill-disable)))
  54
  55 (defun erc-fill-enable ()
  56   "Setup hooks for `erc-fill-mode'."
  57   (interactive)
  58   (add-hook 'erc-insert-modify-hook 'erc-fill)
  59   (add-hook 'erc-send-modify-hook 'erc-fill))
  60
  61 (defun erc-fill-disable ()
  62   "Cleanup hooks, disable `erc-fill-mode'."
  63   (interactive)
  64   (remove-hook 'erc-insert-modify-hook 'erc-fill)
  65   (remove-hook 'erc-send-modify-hook 'erc-fill))
  66
  67 (defcustom erc-fill-prefix nil
  68   "Values used as `fill-prefix' for `erc-fill-variable'.
  69 nil means fill with space, a string means fill with this string."
  70   :group 'erc-fill
  71   :type '(choice (const nil) string))
  72
  73 (defcustom erc-fill-function 'erc-fill-variable
  74   "Function to use for filling messages.
  75
  76 Variable Filling with an `erc-fill-prefix' of nil:
  77
  78 <shortnick> this is a very very very long message with no
  79             meaning at all
  80
  81 Variable Filling with an `erc-fill-prefix' of four spaces:
  82
  83 <shortnick> this is a very very very long message with no
  84     meaning at all
  85
  86 Static Filling with `erc-fill-static-center' of 27:
  87
  88                 <shortnick> foo bar baz
  89          <a-very-long-nick> foo bar baz quuuuux
  90                 <shortnick> this is a very very very long message with no
  91                             meaning at all
  92
  93 These two styles are implemented using `erc-fill-variable' and
  94 `erc-fill-static'.  You can, of course, define your own filling
  95 function.  Narrowing to the region in question is in effect while your
  96 function is called."
  97   :group 'erc-fill
  98   :type '(choice (const :tag "Variable Filling" erc-fill-variable)
  99                  (const :tag "Static Filling" erc-fill-static)
 100                  function))
 101
 102 (defcustom erc-fill-static-center 27
 103   "Column around which all statically filled messages will be
 104 centered.  This column denotes the point where the ' ' character
 105 between <nickname> and the entered text will be put, thus aligning
 106 nick names right and text left."
 107   :group 'erc-fill
 108   :type 'integer)
 109
 110 (defcustom erc-fill-variable-maximum-indentation 17
 111   "If we indent a line after a long nick, don't indent more then this
 112 characters. Set to nil to disable."
 113   :group 'erc-fill
 114   :type 'integer)
 115
 116 (defcustom erc-fill-column 78
 117   "The column at which a filled paragraph is broken."
 118   :group 'erc-fill
 119   :type 'integer)
 120
 121 ;;;###autoload
 122 (defun erc-fill ()
 123   "Fill a region using the function referenced in `erc-fill-function'.
 124 You can put this on `erc-insert-modify-hook' and/or `erc-send-modify-hook'."
 125   (unless (erc-string-invisible-p (buffer-substring (point-min) (point-max)))
 126     (when erc-fill-function
 127       ;; skip initial empty lines
 128       (goto-char (point-min))
 129       (save-match-data
 130         (while (and (looking-at "[ \t\n]*$")
 131                     (= (forward-line 1) 0))))
 132       (unless (eobp)
 133         (save-restriction
 134           (narrow-to-region (point) (point-max))
 135           (funcall erc-fill-function))))))
 136
 137 (defun erc-fill-static ()
 138   "Fills a text such that messages start at column `erc-fill-static-center'."
 139   (save-match-data
 140     (goto-char (point-min))
 141     (looking-at "^\\(\\S-+\\)")
 142     (let ((nick (match-string 1)))
 143         (let ((fill-column (- erc-fill-column (erc-timestamp-offset)))
 144               (fill-prefix (make-string erc-fill-static-center 32)))
 145           (insert (make-string (max 0 (- erc-fill-static-center
 146                                          (length nick) 1))
 147                                32))
 148           (erc-fill-regarding-timestamp))
 149         (erc-restore-text-properties))))
 150
 151 (defun erc-fill-variable ()
 152   "Fill from `point-min' to `point-max'."
 153   (let ((fill-prefix erc-fill-prefix)
 154         (fill-column (or erc-fill-column fill-column)))
 155     (goto-char (point-min))
 156     (if fill-prefix
 157         (let ((first-line-offset (make-string (erc-timestamp-offset) 32)))
 158           (insert first-line-offset)
 159           (fill-region (point-min) (point-max) t t)
 160           (goto-char (point-min))
 161           (delete-char (length first-line-offset)))
 162       (save-match-data
 163         (let* ((nickp (looking-at "^\\(\\S-+\\)"))
 164                (nick (if nickp
 165                          (match-string 1)
 166                        ""))
 167                (fill-column (- erc-fill-column (erc-timestamp-offset)))
 168                (fill-prefix (make-string (min (+ 1 (length nick))
 169                                               (- fill-column 1)
 170                                               (or erc-fill-variable-maximum-indentation
 171                                                   fill-column))
 172                                          32)))
 173           (erc-fill-regarding-timestamp))))
 174     (erc-restore-text-properties)))
 175
 176 (defun erc-fill-regarding-timestamp ()
 177   "Fills a text such that messages start at column `erc-fill-static-center'."
 178   (fill-region (point-min) (point-max) t t)
 179   (goto-char (point-min))
 180   (forward-line)
 181   (indent-rigidly (point) (point-max) (erc-timestamp-offset)))
 182
 183 (defun erc-timestamp-offset ()
 184   "Get length of timestamp if inserted left."
 185   (if (and (boundp 'erc-timestamp-format)
 186            erc-timestamp-format
 187            (eq erc-insert-timestamp-function 'erc-insert-timestamp-left)
 188            (not erc-hide-timestamps))
 189       (length (format-time-string erc-timestamp-format))
 190     0))
 191
 192 (provide 'erc-fill)
 193
 194 ;;; erc-fill.el ends here
 195 ;; Local Variables:
 196 ;; indent-tabs-mode: nil
 197 ;; End:
 198