lisp/iimage.el

   1 ;;; iimage.el --- Inline image minor mode.
   2
   3 ;; Copyright (C) 2004-2017 Free Software Foundation, Inc.
   4
   5 ;; Author: KOSEKI Yoshinori <kose@meadowy.org>
   6 ;; Maintainer: KOSEKI Yoshinori <kose@meadowy.org>
   7 ;; Keywords: multimedia
   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 ;; Iimage is a minor mode that displays images, when image-filename
  27 ;; exists in the buffer.
  28 ;;
  29 ;; ** Display images in *Info* buffer.
  30 ;;
  31 ;; (add-hook 'info-mode-hook 'iimage-mode)
  32 ;;
  33 ;; .texinfo:   @file{file://foo.png}
  34 ;; .info:      `file://foo.png'
  35 ;;
  36 ;; ** Display images in Wiki buffer.
  37 ;;
  38 ;; (add-hook 'wiki-mode-hook 'iimage-mode)
  39 ;;
  40 ;; wiki-file:   [[foo.png]]
  41
  42 ;;; Code:
  43
  44 (eval-when-compile
  45   (require 'image-file))
  46
  47 (defgroup iimage nil
  48   "Support for inline images."
  49   :version "22.1"
  50   :group 'image)
  51
  52 (defcustom iimage-mode-image-search-path nil
  53   "List of directories to search for image files for iimage-mode."
  54   :type '(choice (const nil) (repeat directory))
  55   :group 'iimage)
  56
  57 (defvar iimage-mode-image-filename-regex
  58   (concat "[-+./_0-9a-zA-Z]+\\."
  59           (regexp-opt (nconc (mapcar #'upcase
  60                                      image-file-name-extensions)
  61                              image-file-name-extensions)
  62                       t)))
  63
  64 (defcustom iimage-mode-image-regex-alist
  65   `((,(concat "\\(`?file://\\|\\[\\[\\|<\\|`\\)?"
  66               "\\(" iimage-mode-image-filename-regex "\\)"
  67               "\\(\\]\\]\\|>\\|'\\)?") . 2))
  68   "Alist of filename REGEXP vs NUM.
  69 Each element looks like (REGEXP . NUM).
  70 NUM specifies which parenthesized expression in the regexp.
  71
  72 Examples of image filename patterns to match:
  73     file://foo.png
  74     \\=`file://foo.png\\='
  75     \\[\\[foo.gif]]
  76     <foo.png>
  77      foo.JPG
  78 "
  79   :type '(alist :key-type regexp :value-type integer)
  80   :group 'iimage)
  81
  82 (defvar iimage-mode-map
  83   (let ((map (make-sparse-keymap)))
  84     (define-key map "\C-l" 'iimage-recenter)
  85     map)
  86   "Keymap used in `iimage-mode'.")
  87
  88 (defun iimage-recenter (&optional arg)
  89   "Re-draw images and recenter."
  90   (interactive "P")
  91   (iimage-mode-buffer nil)
  92   (iimage-mode-buffer t)
  93   (recenter arg))
  94
  95 ;;;###autoload
  96 (define-obsolete-function-alias 'turn-on-iimage-mode 'iimage-mode "24.1")
  97
  98 (defun turn-off-iimage-mode ()
  99   "Unconditionally turn off iimage mode."
 100   (interactive)
 101   (iimage-mode 0))
 102
 103 (defun iimage-modification-hook (beg end)
 104   "Remove display property if a display region is modified."
 105   ;;(debug-print "ii1 begin %d, end %d\n" beg end)
 106   (let ((inhibit-modification-hooks t)
 107         (beg (previous-single-property-change end 'display
 108                                               nil (line-beginning-position)))
 109         (end (next-single-property-change     beg 'display
 110                                               nil (line-end-position))))
 111     (when (and beg end (plist-get (text-properties-at beg) 'display))
 112       ;;(debug-print "ii2 begin %d, end %d\n" beg end)
 113       (remove-text-properties beg end
 114                               '(display nil modification-hooks nil)))))
 115
 116 (defun iimage-mode-buffer (arg)
 117   "Display images if ARG is non-nil, undisplay them otherwise."
 118   (let ((image-path (cons default-directory iimage-mode-image-search-path))
 119         file)
 120     (with-silent-modifications
 121       (save-excursion
 122         (goto-char (point-min))
 123         (dolist (pair iimage-mode-image-regex-alist)
 124           (while (re-search-forward (car pair) nil t)
 125             (when (and (setq file (match-string (cdr pair)))
 126                        (setq file (locate-file file image-path)))
 127               ;; FIXME: we don't mark our images, so we can't reliably
 128               ;; remove them either (we may leave some of ours, and we
 129               ;; may remove other packages's display properties).
 130               (if arg
 131                   (add-text-properties (match-beginning 0) (match-end 0)
 132                                        `(display ,(create-image file)
 133                                          modification-hooks
 134                                          (iimage-modification-hook)))
 135                 (remove-text-properties (match-beginning 0) (match-end 0)
 136                                         '(display modification-hooks))))))))))
 137
 138 ;;;###autoload
 139 (define-minor-mode iimage-mode nil
 140   :group 'iimage :lighter " iImg" :keymap iimage-mode-map
 141   (iimage-mode-buffer iimage-mode))
 142
 143 (provide 'iimage)
 144
 145 ;;; iimage.el ends here