lisp/erc/erc-fill.el

   1 ;;; erc-fill.el --- Filling IRC messages in various ways
   2
   3 ;; Copyright (C) 2001, 2002, 2003, 2004, 2006,
   4 ;;   2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
   5
   6 ;; Author: Andreas Fuchs <asf@void.at>
   7 ;;         Mario Lang <mlang@delysid.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 numeric arg, turn ERC fill mode on if and only if arg is
  44 positive.  In ERC fill mode, messages in the channel buffers are
  45 filled."
  46   nil nil nil
  47   :global t :group 'erc-fill
  48   (if erc-fill-mode
  49       (erc-fill-enable)
  50     (erc-fill-disable)))
  51
  52 (defun erc-fill-enable ()
  53   "Setup hooks for `erc-fill-mode'."
  54   (interactive)
  55   (add-hook 'erc-insert-modify-hook 'erc-fill)
  56   (add-hook 'erc-send-modify-hook 'erc-fill))
  57
  58 (defun erc-fill-disable ()
  59   "Cleanup hooks, disable `erc-fill-mode'."
  60   (interactive)
  61   (remove-hook 'erc-insert-modify-hook 'erc-fill)
  62   (remove-hook 'erc-send-modify-hook 'erc-fill))
  63
  64 (defcustom erc-fill-prefix nil
  65   "Values used as `fill-prefix' for `erc-fill-variable'.
  66 nil means fill with space, a string means fill with this string."
  67   :group 'erc-fill
  68   :type '(choice (const nil) string))
  69
  70 (defcustom erc-fill-function 'erc-fill-variable
  71   "Function to use for filling messages.
  72
  73 Variable Filling with an `erc-fill-prefix' of nil:
  74
  75 <shortnick> this is a very very very long message with no
  76             meaning at all
  77
  78 Variable Filling with an `erc-fill-prefix' of four spaces:
  79
  80 <shortnick> this is a very very very long message with no
  81     meaning at all
  82
  83 Static Filling with `erc-fill-static-center' of 27:
  84
  85                 <shortnick> foo bar baz
  86          <a-very-long-nick> foo bar baz quuuuux
  87                 <shortnick> this is a very very very long message with no
  88                             meaning at all
  89
  90 These two styles are implemented using `erc-fill-variable' and
  91 `erc-fill-static'.  You can, of course, define your own filling
  92 function.  Narrowing to the region in question is in effect while your
  93 function is called."
  94   :group 'erc-fill
  95   :type '(choice (const :tag "Variable Filling" erc-fill-variable)
  96                  (const :tag "Static Filling" erc-fill-static)
  97                  function))
  98
  99 (defcustom erc-fill-static-center 27
 100   "Column around which all statically filled messages will be
 101 centered.  This column denotes the point where the ' ' character
 102 between <nickname> and the entered text will be put, thus aligning
 103 nick names right and text left."
 104   :group 'erc-fill
 105   :type 'integer)
 106
 107 (defcustom erc-fill-variable-maximum-indentation 17
 108   "If we indent a line after a long nick, don't indent more then this
 109 characters. Set to nil to disable."
 110   :group 'erc-fill
 111   :type 'integer)
 112
 113 (defcustom erc-fill-column 78
 114   "The column at which a filled paragraph is broken."
 115   :group 'erc-fill
 116   :type 'integer)
 117
 118 ;;;###autoload
 119 (defun erc-fill ()
 120   "Fill a region using the function referenced in `erc-fill-function'.
 121 You can put this on `erc-insert-modify-hook' and/or `erc-send-modify-hook'."
 122   (unless (erc-string-invisible-p (buffer-substring (point-min) (point-max)))
 123     (when erc-fill-function
 124       ;; skip initial empty lines
 125       (goto-char (point-min))
 126       (save-match-data
 127         (while (and (looking-at "[ \t\n]*$")
 128                     (= (forward-line 1) 0))))
 129       (unless (eobp)
 130         (save-restriction
 131           (narrow-to-region (point) (point-max))
 132           (funcall erc-fill-function))))))
 133
 134 (defun erc-fill-static ()
 135   "Fills a text such that messages start at column `erc-fill-static-center'."
 136   (save-match-data
 137     (goto-char (point-min))
 138     (looking-at "^\\(\\S-+\\)")
 139     (let ((nick (match-string 1)))
 140         (let ((fill-column (- erc-fill-column (erc-timestamp-offset)))
 141               (fill-prefix (make-string erc-fill-static-center 32)))
 142           (insert (make-string (max 0 (- erc-fill-static-center
 143                                          (length nick) 1))
 144                                32))
 145           (erc-fill-regarding-timestamp))
 146         (erc-restore-text-properties))))
 147
 148 (defun erc-fill-variable ()
 149   "Fill from `point-min' to `point-max'."
 150   (let ((fill-prefix erc-fill-prefix)
 151         (fill-column (or erc-fill-column fill-column)))
 152     (goto-char (point-min))
 153     (if fill-prefix
 154         (let ((first-line-offset (make-string (erc-timestamp-offset) 32)))
 155           (insert first-line-offset)
 156           (fill-region (point-min) (point-max) t t)
 157           (goto-char (point-min))
 158           (delete-char (length first-line-offset)))
 159       (save-match-data
 160         (let* ((nickp (looking-at "^\\(\\S-+\\)"))
 161                (nick (if nickp
 162                          (match-string 1)
 163                        ""))
 164                (fill-column (- erc-fill-column (erc-timestamp-offset)))
 165                (fill-prefix (make-string (min (+ 1 (length nick))
 166                                               (- fill-column 1)
 167                                               (or erc-fill-variable-maximum-indentation
 168                                                   fill-column))
 169                                          32)))
 170           (erc-fill-regarding-timestamp))))
 171     (erc-restore-text-properties)))
 172
 173 (defun erc-fill-regarding-timestamp ()
 174   "Fills a text such that messages start at column `erc-fill-static-center'."
 175   (fill-region (point-min) (point-max) t t)
 176   (goto-char (point-min))
 177   (forward-line)
 178   (indent-rigidly (point) (point-max) (erc-timestamp-offset)))
 179
 180 (defun erc-timestamp-offset ()
 181   "Get length of timestamp if inserted left."
 182   (if (and (boundp 'erc-timestamp-format)
 183            erc-timestamp-format
 184            (eq erc-insert-timestamp-function 'erc-insert-timestamp-left)
 185            (not erc-hide-timestamps))
 186       (length (format-time-string erc-timestamp-format))
 187     0))
 188
 189 (provide 'erc-fill)
 190
 191 ;;; erc-fill.el ends here
 192 ;; Local Variables:
 193 ;; indent-tabs-mode: nil
 194 ;; End:
 195