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1 | ;;; image-file.el --- Support for visiting image files |
2 | ;; | |
3 | ;; Copyright (C) 2000 Free Software Foundation, Inc. | |
4 | ;; | |
5 | ;; Author: Miles Bader <miles@gnu.org> | |
6 | ;; Keywords: multimedia | |
7 | ||
8 | ;; This file is part of GNU Emacs. | |
9 | ||
10 | ;; GNU Emacs is free software; you can redistribute it and/or modify | |
11 | ;; it under the terms of the GNU General Public License as published by | |
12 | ;; the Free Software Foundation; either version 2, or (at your option) | |
13 | ;; any later version. | |
14 | ||
15 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
16 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
18 | ;; GNU General Public License for more details. | |
19 | ||
20 | ;; You should have received a copy of the GNU General Public License | |
21 | ;; along with GNU Emacs; see the file COPYING. If not, write to the | |
22 | ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
23 | ;; Boston, MA 02111-1307, USA. | |
24 | ||
25 | ;;; Commentary: | |
26 | ||
27 | ;; Defines a file-name-handler hook that transforms visited (or | |
db623cef | 28 | ;; inserted) image files so that they are displayed by emacs as |
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29 | ;; images. This is done by putting a `display' text-property on the |
30 | ;; image data, with the image-data still present underneath; if the | |
31 | ;; resulting buffer file is saved to another name it will correctly save | |
32 | ;; the image data to the new file. | |
33 | ||
34 | ;;; Code: | |
35 | ||
36 | (require 'image) | |
37 | ||
75e5b373 | 38 | |
1c7e37a9 | 39 | ;;;###autoload |
75e5b373 | 40 | (defcustom image-file-name-extensions |
db623cef | 41 | '("png" "jpeg" "jpg" "gif" "tiff" "xbm" "xpm" "pbm") |
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42 | "*A list of image-file filename extensions. |
43 | Filenames having one of these extensions are considered image files, | |
44 | in addition to those matching `image-file-name-regexps'. | |
45 | ||
46 | See `auto-image-file-mode'; if `auto-image-file-mode' is enabled, | |
47 | setting this variable directly does not take effect unless | |
48 | `auto-image-file-mode' is re-enabled; this happens automatically the | |
49 | variable is set using \\[customize]." | |
50 | :type '(repeat string) | |
51 | :set (lambda (sym val) | |
52 | (set-default sym val) | |
53 | (when auto-image-file-mode | |
54 | ;; Re-initialize the image-file handler | |
55 | (auto-image-file-mode t))) | |
5859e61a | 56 | :initialize 'custom-initialize-default |
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57 | :group 'image) |
58 | ||
1c7e37a9 | 59 | ;;;###autoload |
75e5b373 | 60 | (defcustom image-file-name-regexps nil |
34a19346 | 61 | "*List of regexps matching image-file filenames. |
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62 | Filenames matching one of these regexps are considered image files, |
63 | in addition to those with an extension in `image-file-name-extensions'. | |
5859e61a | 64 | |
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65 | See function `auto-image-file-mode'; if `auto-image-file-mode' is |
66 | enabled, setting this variable directly does not take effect unless | |
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67 | `auto-image-file-mode' is re-enabled; this happens automatically the |
68 | variable is set using \\[customize]." | |
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69 | :type '(repeat regexp) |
70 | :set (lambda (sym val) | |
71 | (set-default sym val) | |
75e5b373 | 72 | (when auto-image-file-mode |
5859e61a | 73 | ;; Re-initialize the image-file handler |
75e5b373 | 74 | (auto-image-file-mode t))) |
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75 | :initialize 'custom-initialize-default |
76 | :group 'image) | |
77 | ||
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78 | |
79 | ;;;###autoload | |
80 | (defun image-file-name-regexp () | |
34a19346 | 81 | "Return a regular expression matching image-file filenames." |
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82 | (let ((exts-regexp |
83 | (and image-file-name-extensions | |
84 | (concat "\\." | |
85 | (regexp-opt image-file-name-extensions t) | |
86 | "\\'")))) | |
87 | (if image-file-name-regexps | |
88 | (mapconcat 'identity | |
89 | (if exts-regexp | |
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90 | (cons exts-regexp image-file-name-regexps) |
91 | image-file-name-regexps) | |
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92 | "\\|") |
93 | exts-regexp))) | |
94 | ||
95 | ||
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96 | ;;;###autoload |
97 | (defun insert-image-file (file &optional visit beg end replace) | |
98 | "Insert the image file FILE into the current buffer. | |
99 | Optional arguments VISIT, BEG, END, and REPLACE are interpreted as for | |
100 | the command `insert-file-contents'." | |
101 | (let ((rval | |
102 | (image-file-call-underlying #'insert-file-contents-literally | |
103 | 'insert-file-contents | |
104 | file visit beg end replace))) | |
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105 | ;; Turn the image data into a real image, but only if the whole file |
106 | ;; was inserted | |
107 | (when (and (or (null beg) (zerop beg)) (null end)) | |
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108 | (let* ((ibeg (point)) |
109 | (iend (+ (point) (cadr rval))) | |
110 | (data | |
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111 | (string-make-unibyte |
112 | (buffer-substring-no-properties ibeg iend))) | |
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113 | (image |
114 | (create-image data nil t)) | |
115 | (props | |
116 | `(display ,image | |
117 | intangible ,image | |
e5a9dabf | 118 | rear-nonsticky (display intangible read-only) |
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119 | ;; This a cheap attempt to make the whole buffer |
120 | ;; read-only when we're visiting the file. | |
121 | ,@(and visit | |
122 | (= ibeg (point-min)) | |
123 | (= iend (point-max)) | |
124 | '(read-only t front-sticky (read-only)))))) | |
125 | (add-text-properties ibeg iend props))) | |
126 | rval)) | |
127 | ||
128 | (defun image-file-handler (operation &rest args) | |
34a19346 | 129 | "Filename handler for inserting image files. |
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130 | OPERATION is the operation to perform, on ARGS. |
131 | See `file-name-handler-alist' for details." | |
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132 | (if (and (eq operation 'insert-file-contents) |
133 | auto-image-file-mode) | |
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134 | (apply #'insert-image-file args) |
135 | ;; We don't handle OPERATION, use another handler or the default | |
136 | (apply #'image-file-call-underlying operation operation args))) | |
137 | ||
138 | (defun image-file-call-underlying (function operation &rest args) | |
139 | "Call FUNCTION with `image-file-handler' and OPERATION inhibited. | |
140 | Optional argument ARGS are the arguments to call FUNCTION with." | |
141 | (let ((inhibit-file-name-handlers | |
142 | (cons 'image-file-handler | |
143 | (and (eq inhibit-file-name-operation operation) | |
144 | inhibit-file-name-handlers))) | |
145 | (inhibit-file-name-operation operation)) | |
146 | (apply function args))) | |
147 | ||
5859e61a | 148 | |
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149 | ;;; Note this definition must be at the end of the file, because |
150 | ;;; `define-minor-mode' actually calls the mode-function if the | |
151 | ;;; associated variable is non-nil, which requires that all needed | |
152 | ;;; functions be already defined. [This is arguably a bug in d-m-m] | |
153 | ;;;###autoload | |
154 | (define-minor-mode auto-image-file-mode | |
155 | "Toggle visiting of image files as images. | |
156 | With prefix argument ARG, turn on if positive, otherwise off. | |
157 | Returns non-nil if the new state is enabled. | |
158 | ||
159 | Image files are those whose name has an extension in | |
160 | `image-file-name-extensions', or matches a regexp in | |
161 | `image-file-name-regexps'." | |
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162 | :global t |
163 | :group 'image | |
164 | ;; Remove existing handler | |
165 | (let ((existing-entry | |
166 | (rassq 'image-file-handler file-name-handler-alist))) | |
167 | (when existing-entry | |
168 | (setq file-name-handler-alist | |
169 | (delq existing-entry file-name-handler-alist)))) | |
170 | ;; Add new handler, if enabled | |
171 | (when auto-image-file-mode | |
172 | (push (cons (image-file-name-regexp) 'image-file-handler) | |
173 | file-name-handler-alist))) | |
174 | ||
175 | ||
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176 | (provide 'image-file) |
177 | ||
178 | ;;; image-file.el ends here |