lisp/erc/erc-fill.el

   1 ;;; erc-fill.el --- Filling IRC messages in various ways
   2
   3 ;; Copyright (C) 2001-2004, 2006-2012 Free Software Foundation, Inc.
   4
   5 ;; Author: Andreas Fuchs <asf@void.at>
   6 ;;         Mario Lang <mlang@delysid.org>
   7 ;; URL: http://www.emacswiki.org/cgi-bin/wiki.pl?ErcFilling
   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 ;;; Commentary:
  25
  26 ;; This package implements filling of messages sent and received.  Use
  27 ;; `erc-fill-mode' to switch it on.  Customize `erc-fill-function' to
  28 ;; change the style.
  29
  30 ;;; Code:
  31
  32 (require 'erc)
  33 (require 'erc-stamp); for the timestamp stuff
  34
  35 (defgroup erc-fill nil
  36   "Filling means to reformat long lines in different ways."
  37   :group 'erc)
  38
  39 ;;;###autoload (autoload 'erc-fill-mode "erc-fill" nil t)
  40 (erc-define-minor-mode erc-fill-mode
  41   "Toggle ERC fill mode.
  42 With a prefix argument ARG, enable ERC fill mode if ARG is
  43 positive, and disable it otherwise.  If called from Lisp, enable
  44 the mode if ARG is omitted or nil.
  45
  46 ERC fill mode is a global minor mode.  When enabled, messages in
  47 the channel buffers are filled."
  48   nil nil nil
  49   :global t :group 'erc-fill
  50   (if erc-fill-mode
  51       (erc-fill-enable)
  52     (erc-fill-disable)))
  53
  54 (defun erc-fill-enable ()
  55   "Setup hooks for `erc-fill-mode'."
  56   (interactive)
  57   (add-hook 'erc-insert-modify-hook 'erc-fill)
  58   (add-hook 'erc-send-modify-hook 'erc-fill))
  59
  60 (defun erc-fill-disable ()
  61   "Cleanup hooks, disable `erc-fill-mode'."
  62   (interactive)
  63   (remove-hook 'erc-insert-modify-hook 'erc-fill)
  64   (remove-hook 'erc-send-modify-hook 'erc-fill))
  65
  66 (defcustom erc-fill-prefix nil
  67   "Values used as `fill-prefix' for `erc-fill-variable'.
  68 nil means fill with space, a string means fill with this string."
  69   :group 'erc-fill
  70   :type '(choice (const nil) string))
  71
  72 (defcustom erc-fill-function 'erc-fill-variable
  73   "Function to use for filling messages.
  74
  75 Variable Filling with an `erc-fill-prefix' of nil:
  76
  77 <shortnick> this is a very very very long message with no
  78             meaning at all
  79
  80 Variable Filling with an `erc-fill-prefix' of four spaces:
  81
  82 <shortnick> this is a very very very long message with no
  83     meaning at all
  84
  85 Static Filling with `erc-fill-static-center' of 27:
  86
  87                 <shortnick> foo bar baz
  88          <a-very-long-nick> foo bar baz quuuuux
  89                 <shortnick> this is a very very very long message with no
  90                             meaning at all
  91
  92 These two styles are implemented using `erc-fill-variable' and
  93 `erc-fill-static'.  You can, of course, define your own filling
  94 function.  Narrowing to the region in question is in effect while your
  95 function is called."
  96   :group 'erc-fill
  97   :type '(choice (const :tag "Variable Filling" erc-fill-variable)
  98                  (const :tag "Static Filling" erc-fill-static)
  99                  function))
 100
 101 (defcustom erc-fill-static-center 27
 102   "Column around which all statically filled messages will be
 103 centered.  This column denotes the point where the ' ' character
 104 between <nickname> and the entered text will be put, thus aligning
 105 nick names right and text left."
 106   :group 'erc-fill
 107   :type 'integer)
 108
 109 (defcustom erc-fill-variable-maximum-indentation 17
 110   "If we indent a line after a long nick, don't indent more then this
 111 characters. Set to nil to disable."
 112   :group 'erc-fill
 113   :type 'integer)
 114
 115 (defcustom erc-fill-column 78
 116   "The column at which a filled paragraph is broken."
 117   :group 'erc-fill
 118   :type 'integer)
 119
 120 ;;;###autoload
 121 (defun erc-fill ()
 122   "Fill a region using the function referenced in `erc-fill-function'.
 123 You can put this on `erc-insert-modify-hook' and/or `erc-send-modify-hook'."
 124   (unless (erc-string-invisible-p (buffer-substring (point-min) (point-max)))
 125     (when erc-fill-function
 126       ;; skip initial empty lines
 127       (goto-char (point-min))
 128       (save-match-data
 129         (while (and (looking-at "[ \t\n]*$")
 130                     (= (forward-line 1) 0))))
 131       (unless (eobp)
 132         (save-restriction
 133           (narrow-to-region (point) (point-max))
 134           (funcall erc-fill-function))))))
 135
 136 (defun erc-fill-static ()
 137   "Fills a text such that messages start at column `erc-fill-static-center'."
 138   (save-match-data
 139     (goto-char (point-min))
 140     (looking-at "^\\(\\S-+\\)")
 141     (let ((nick (match-string 1)))
 142         (let ((fill-column (- erc-fill-column (erc-timestamp-offset)))
 143               (fill-prefix (make-string erc-fill-static-center 32)))
 144           (insert (make-string (max 0 (- erc-fill-static-center
 145                                          (length nick) 1))
 146                                32))
 147           (erc-fill-regarding-timestamp))
 148         (erc-restore-text-properties))))
 149
 150 (defun erc-fill-variable ()
 151   "Fill from `point-min' to `point-max'."
 152   (let ((fill-prefix erc-fill-prefix)
 153         (fill-column (or erc-fill-column fill-column)))
 154     (goto-char (point-min))
 155     (if fill-prefix
 156         (let ((first-line-offset (make-string (erc-timestamp-offset) 32)))
 157           (insert first-line-offset)
 158           (fill-region (point-min) (point-max) t t)
 159           (goto-char (point-min))
 160           (delete-char (length first-line-offset)))
 161       (save-match-data
 162         (let* ((nickp (looking-at "^\\(\\S-+\\)"))
 163                (nick (if nickp
 164                          (match-string 1)
 165                        ""))
 166                (fill-column (- erc-fill-column (erc-timestamp-offset)))
 167                (fill-prefix (make-string (min (+ 1 (length nick))
 168                                               (- fill-column 1)
 169                                               (or erc-fill-variable-maximum-indentation
 170                                                   fill-column))
 171                                          32)))
 172           (erc-fill-regarding-timestamp))))
 173     (erc-restore-text-properties)))
 174
 175 (defun erc-fill-regarding-timestamp ()
 176   "Fills a text such that messages start at column `erc-fill-static-center'."
 177   (fill-region (point-min) (point-max) t t)
 178   (goto-char (point-min))
 179   (forward-line)
 180   (indent-rigidly (point) (point-max) (erc-timestamp-offset)))
 181
 182 (defun erc-timestamp-offset ()
 183   "Get length of timestamp if inserted left."
 184   (if (and (boundp 'erc-timestamp-format)
 185            erc-timestamp-format
 186            (eq erc-insert-timestamp-function 'erc-insert-timestamp-left)
 187            (not erc-hide-timestamps))
 188       (length (format-time-string erc-timestamp-format))
 189     0))
 190
 191 (provide 'erc-fill)
 192
 193 ;;; erc-fill.el ends here
 194 ;; Local Variables:
 195 ;; indent-tabs-mode: nil
 196 ;; End:
 197