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7840ced1 GM |
1 | ;;; image.el --- image API |
2 | ||
3c3b34d2 | 3 | ;; Copyright (C) 1998, 99, 2000, 01, 04 Free Software Foundation, Inc. |
634f4a67 PJ |
4 | |
5 | ;; Maintainer: FSF | |
04799cf5 | 6 | ;; Keywords: multimedia |
7840ced1 GM |
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 | ;;; Code: | |
28 | ||
77f6105c MB |
29 | |
30 | (defgroup image () | |
31 | "Image support." | |
32 | :group 'multimedia) | |
33 | ||
34 | ||
7840ced1 | 35 | (defconst image-type-regexps |
3bdbead3 | 36 | '(("\\`/[\t\n\r ]*\\*.*XPM.\\*/" . xpm) |
69ebef1d GM |
37 | ("\\`P[1-6]" . pbm) |
38 | ("\\`GIF8" . gif) | |
69ebef1d | 39 | ("\\`\211PNG\r\n" . png) |
3bdbead3 | 40 | ("\\`[\t\n\r ]*#define" . xbm) |
6ea3db8a | 41 | ("\\`\\(MM\0\\*\\|II\\*\0\\)" . tiff) |
3bdbead3 | 42 | ("\\`[\t\n\r ]*%!PS" . postscript) |
8a8ef149 | 43 | ("\\`\xff\xd8" . (image-jpeg-p . jpeg))) |
7840ced1 GM |
44 | "Alist of (REGEXP . IMAGE-TYPE) pairs used to auto-detect image types. |
45 | When the first bytes of an image file match REGEXP, it is assumed to | |
8a8ef149 GM |
46 | be of image type IMAGE-TYPE if IMAGE-TYPE is a symbol. If not a symbol, |
47 | IMAGE-TYPE must be a pair (PREDICATE . TYPE). PREDICATE is called | |
48 | with one argument, a string containing the image data. If PREDICATE returns | |
37d4a06e | 49 | a non-nil value, TYPE is the image's type.") |
8a8ef149 | 50 | |
3c3b34d2 JB |
51 | ;;;###autoload |
52 | (defvar image-library-alist nil | |
53 | "Alist of image types vs external libraries needed to display them. | |
54 | ||
55 | Each element is a list (IMAGE-TYPE LIBRARY...), where the car is a symbol | |
56 | representing a supported image type, and the rest are strings giving | |
143b8c27 JB |
57 | alternate filenames for the corresponding external libraries. |
58 | ||
59 | Emacs tries to load the libraries in the order they appear on the | |
60 | list; if none is loaded, the running session of Emacs won't | |
61 | support the image type. Types 'pbm and 'xbm don't need to be | |
62 | listed; they're always supported.") | |
3c3b34d2 | 63 | ;;;###autoload (put 'image-library-alist 'risky-local-variable t) |
8a8ef149 GM |
64 | |
65 | (defun image-jpeg-p (data) | |
9b78a6a3 RS |
66 | "Value is non-nil if DATA, a string, consists of JFIF image data. |
67 | We accept the tag Exif because that is the same format." | |
8a8ef149 GM |
68 | (when (string-match "\\`\xff\xd8" data) |
69 | (catch 'jfif | |
70 | (let ((len (length data)) (i 2)) | |
71 | (while (< i len) | |
72 | (when (/= (aref data i) #xff) | |
73 | (throw 'jfif nil)) | |
74 | (setq i (1+ i)) | |
75 | (when (>= (+ i 2) len) | |
76 | (throw 'jfif nil)) | |
77 | (let ((nbytes (+ (lsh (aref data (+ i 1)) 8) | |
4a9bf8a4 GM |
78 | (aref data (+ i 2)))) |
79 | (code (aref data i))) | |
80 | (when (and (>= code #xe0) (<= code #xef)) | |
8a8ef149 | 81 | ;; APP0 LEN1 LEN2 "JFIF\0" |
71296446 | 82 | (throw 'jfif |
32b3c766 JPW |
83 | (string-match "JFIF\\|Exif" |
84 | (substring data i (min (+ i nbytes) len))))) | |
3bdbead3 | 85 | (setq i (+ i 1 nbytes)))))))) |
7840ced1 GM |
86 | |
87 | ||
88 | ;;;###autoload | |
162dec01 GM |
89 | (defun image-type-from-data (data) |
90 | "Determine the image type from image data DATA. | |
91 | Value is a symbol specifying the image type or nil if type cannot | |
7840ced1 | 92 | be determined." |
162dec01 | 93 | (let ((types image-type-regexps) |
7840ced1 GM |
94 | type) |
95 | (while (and types (null type)) | |
96 | (let ((regexp (car (car types))) | |
97 | (image-type (cdr (car types)))) | |
8a8ef149 GM |
98 | (when (or (and (symbolp image-type) |
99 | (string-match regexp data)) | |
100 | (and (consp image-type) | |
101 | (funcall (car image-type) data) | |
102 | (setq image-type (cdr image-type)))) | |
7840ced1 GM |
103 | (setq type image-type)) |
104 | (setq types (cdr types)))) | |
105 | type)) | |
106 | ||
107 | ||
162dec01 GM |
108 | ;;;###autoload |
109 | (defun image-type-from-file-header (file) | |
110 | "Determine the type of image file FILE from its first few bytes. | |
111 | Value is a symbol specifying the image type, or nil if type cannot | |
112 | be determined." | |
113 | (unless (file-name-directory file) | |
114 | (setq file (expand-file-name file data-directory))) | |
115 | (setq file (expand-file-name file)) | |
116 | (let ((header (with-temp-buffer | |
ee485a83 | 117 | (set-buffer-multibyte nil) |
162dec01 GM |
118 | (insert-file-contents-literally file nil 0 256) |
119 | (buffer-string)))) | |
120 | (image-type-from-data header))) | |
121 | ||
122 | ||
7840ced1 GM |
123 | ;;;###autoload |
124 | (defun image-type-available-p (type) | |
125 | "Value is non-nil if image type TYPE is available. | |
126 | Image types are symbols like `xbm' or `jpeg'." | |
3c3b34d2 JB |
127 | (and (fboundp 'init-image-library) |
128 | (init-image-library type image-library-alist))) | |
7840ced1 GM |
129 | |
130 | ;;;###autoload | |
162dec01 GM |
131 | (defun create-image (file-or-data &optional type data-p &rest props) |
132 | "Create an image. | |
133 | FILE-OR-DATA is an image file name or image data. | |
7840ced1 | 134 | Optional TYPE is a symbol describing the image type. If TYPE is omitted |
162dec01 GM |
135 | or nil, try to determine the image type from its first few bytes |
136 | of image data. If that doesn't work, and FILE-OR-DATA is a file name, | |
9ea8de1b | 137 | use its file extension as image type. |
162dec01 | 138 | Optional DATA-P non-nil means FILE-OR-DATA is a string containing image data. |
7840ced1 | 139 | Optional PROPS are additional image attributes to assign to the image, |
d1d3c685 | 140 | like, e.g. `:mask MASK'. |
7840ced1 | 141 | Value is the image created, or nil if images of type TYPE are not supported." |
f64ae86c GM |
142 | (when (and (not data-p) (not (stringp file-or-data))) |
143 | (error "Invalid image file name `%s'" file-or-data)) | |
162dec01 GM |
144 | (cond ((null data-p) |
145 | ;; FILE-OR-DATA is a file name. | |
146 | (unless (or type | |
147 | (setq type (image-type-from-file-header file-or-data))) | |
148 | (let ((extension (file-name-extension file-or-data))) | |
149 | (unless extension | |
150 | (error "Cannot determine image type")) | |
151 | (setq type (intern extension))))) | |
152 | (t | |
153 | ;; FILE-OR-DATA contains image data. | |
154 | (unless type | |
155 | (setq type (image-type-from-data file-or-data))))) | |
156 | (unless type | |
157 | (error "Cannot determine image type")) | |
7840ced1 | 158 | (unless (symbolp type) |
162dec01 | 159 | (error "Invalid image type `%s'" type)) |
7840ced1 | 160 | (when (image-type-available-p type) |
162dec01 GM |
161 | (append (list 'image :type type (if data-p :data :file) file-or-data) |
162 | props))) | |
7840ced1 GM |
163 | |
164 | ||
165 | ;;;###autoload | |
cedbd8d0 | 166 | (defun put-image (image pos &optional string area) |
1571b5ff | 167 | "Put image IMAGE in front of POS in the current buffer. |
7840ced1 | 168 | IMAGE must be an image created with `create-image' or `defimage'. |
46655c94 GM |
169 | IMAGE is displayed by putting an overlay into the current buffer with a |
170 | `before-string' STRING that has a `display' property whose value is the | |
cedbd8d0 | 171 | image. STRING is defaulted if you omit it. |
7840ced1 | 172 | POS may be an integer or marker. |
7840ced1 GM |
173 | AREA is where to display the image. AREA nil or omitted means |
174 | display it in the text area, a value of `left-margin' means | |
175 | display it in the left marginal area, a value of `right-margin' | |
46655c94 | 176 | means display it in the right marginal area." |
0ad550ba | 177 | (unless string (setq string "x")) |
1571b5ff | 178 | (let ((buffer (current-buffer))) |
cedbd8d0 | 179 | (unless (eq (car-safe image) 'image) |
1571b5ff GM |
180 | (error "Not an image: %s" image)) |
181 | (unless (or (null area) (memq area '(left-margin right-margin))) | |
182 | (error "Invalid area %s" area)) | |
46655c94 | 183 | (setq string (copy-sequence string)) |
1571b5ff | 184 | (let ((overlay (make-overlay pos pos buffer)) |
46655c94 GM |
185 | (prop (if (null area) image (list (list 'margin area) image)))) |
186 | (put-text-property 0 (length string) 'display prop string) | |
1571b5ff GM |
187 | (overlay-put overlay 'put-image t) |
188 | (overlay-put overlay 'before-string string)))) | |
7840ced1 GM |
189 | |
190 | ||
191 | ;;;###autoload | |
5af275e0 | 192 | (defun insert-image (image &optional string area slice) |
7840ced1 | 193 | "Insert IMAGE into current buffer at point. |
46655c94 | 194 | IMAGE is displayed by inserting STRING into the current buffer |
cedbd8d0 DL |
195 | with a `display' property whose value is the image. STRING is |
196 | defaulted if you omit it. | |
7840ced1 GM |
197 | AREA is where to display the image. AREA nil or omitted means |
198 | display it in the text area, a value of `left-margin' means | |
199 | display it in the left marginal area, a value of `right-margin' | |
5af275e0 KS |
200 | means display it in the right marginal area. |
201 | SLICE specifies slice of IMAGE to insert. SLICE nil or omitted | |
202 | means insert whole image. SLICE is a list (X Y WIDTH HEIGHT) | |
203 | specifying the X and Y positions and WIDTH and HEIGHT of image area | |
204 | to insert. A float value 0.0 - 1.0 means relative to the width or | |
205 | height of the image; integer values are taken as pixel values." | |
0ad550ba DL |
206 | ;; Use a space as least likely to cause trouble when it's a hidden |
207 | ;; character in the buffer. | |
208 | (unless string (setq string " ")) | |
cedbd8d0 | 209 | (unless (eq (car-safe image) 'image) |
7840ced1 GM |
210 | (error "Not an image: %s" image)) |
211 | (unless (or (null area) (memq area '(left-margin right-margin))) | |
212 | (error "Invalid area %s" area)) | |
0dc91c57 DL |
213 | (if area |
214 | (setq image (list (list 'margin area) image)) | |
215 | ;; Cons up a new spec equal but not eq to `image' so that | |
216 | ;; inserting it twice in a row (adjacently) displays two copies of | |
217 | ;; the image. Don't try to avoid this by looking at the display | |
218 | ;; properties on either side so that we DTRT more often with | |
219 | ;; cut-and-paste. (Yanking killed image text next to another copy | |
220 | ;; of it loses anyway.) | |
221 | (setq image (cons 'image (cdr image)))) | |
46655c94 GM |
222 | (let ((start (point))) |
223 | (insert string) | |
224 | (add-text-properties start (point) | |
5af275e0 KS |
225 | `(display ,(if slice |
226 | (list (cons 'slice slice) image) | |
227 | image) rear-nonsticky (display))))) | |
228 | ||
229 | ||
230 | (defun insert-sliced-image (image &optional string area rows cols) | |
231 | (unless string (setq string " ")) | |
232 | (unless (eq (car-safe image) 'image) | |
233 | (error "Not an image: %s" image)) | |
234 | (unless (or (null area) (memq area '(left-margin right-margin))) | |
235 | (error "Invalid area %s" area)) | |
236 | (if area | |
237 | (setq image (list (list 'margin area) image)) | |
238 | ;; Cons up a new spec equal but not eq to `image' so that | |
239 | ;; inserting it twice in a row (adjacently) displays two copies of | |
240 | ;; the image. Don't try to avoid this by looking at the display | |
241 | ;; properties on either side so that we DTRT more often with | |
242 | ;; cut-and-paste. (Yanking killed image text next to another copy | |
243 | ;; of it loses anyway.) | |
244 | (setq image (cons 'image (cdr image)))) | |
245 | (let ((x 0.0) (dx (/ 1.0001 (or cols 1))) | |
246 | (y 0.0) (dy (/ 1.0001 (or rows 1)))) | |
247 | (while (< y 1.0) | |
248 | (while (< x 1.0) | |
249 | (let ((start (point))) | |
250 | (insert string) | |
251 | (add-text-properties start (point) | |
252 | `(display ,(list (list 'slice x y dx dy) image) | |
253 | rear-nonsticky (display))) | |
254 | (setq x (+ x dx)))) | |
255 | (setq x 0.0 | |
256 | y (+ y dy)) | |
3e8b5f3d | 257 | (insert (propertize "\n" 'line-height 0))))) |
5af275e0 | 258 | |
10e2102e | 259 | |
7840ced1 GM |
260 | |
261 | ;;;###autoload | |
262 | (defun remove-images (start end &optional buffer) | |
263 | "Remove images between START and END in BUFFER. | |
264 | Remove only images that were put in BUFFER with calls to `put-image'. | |
265 | BUFFER nil or omitted means use the current buffer." | |
266 | (unless buffer | |
267 | (setq buffer (current-buffer))) | |
268 | (let ((overlays (overlays-in start end))) | |
269 | (while overlays | |
270 | (let ((overlay (car overlays))) | |
271 | (when (overlay-get overlay 'put-image) | |
0c898dd9 DL |
272 | (delete-overlay overlay))) |
273 | (setq overlays (cdr overlays))))) | |
7840ced1 GM |
274 | |
275 | ||
276 | ;;;###autoload | |
349c034d GM |
277 | (defun find-image (specs) |
278 | "Find an image, choosing one of a list of image specifications. | |
7840ced1 | 279 | |
cedbd8d0 | 280 | SPECS is a list of image specifications. |
7840ced1 GM |
281 | |
282 | Each image specification in SPECS is a property list. The contents of | |
283 | a specification are image type dependent. All specifications must at | |
bc283707 WP |
284 | least contain the properties `:type TYPE' and either `:file FILE' or |
285 | `:data DATA', where TYPE is a symbol specifying the image type, | |
286 | e.g. `xbm', FILE is the file to load the image from, and DATA is a | |
cedbd8d0 DL |
287 | string containing the actual image data. The specification whose TYPE |
288 | is supported, and FILE exists, is used to construct the image | |
289 | specification to be returned. Return nil if no specification is | |
290 | satisfied. | |
291 | ||
292 | The image is looked for first on `load-path' and then in `data-directory'." | |
7840ced1 GM |
293 | (let (image) |
294 | (while (and specs (null image)) | |
295 | (let* ((spec (car specs)) | |
296 | (type (plist-get spec :type)) | |
162dec01 | 297 | (data (plist-get spec :data)) |
7f228379 GM |
298 | (file (plist-get spec :file)) |
299 | found) | |
162dec01 GM |
300 | (when (image-type-available-p type) |
301 | (cond ((stringp file) | |
7f228379 GM |
302 | (let ((path load-path)) |
303 | (while (and (not found) path) | |
304 | (let ((try-file (expand-file-name file (car path)))) | |
305 | (when (file-readable-p try-file) | |
306 | (setq found try-file))) | |
307 | (setq path (cdr path))) | |
308 | (unless found | |
cedbd8d0 DL |
309 | (let ((try-file (expand-file-name file data-directory))) |
310 | (if (file-readable-p try-file) | |
311 | (setq found try-file)))) | |
312 | (if found | |
313 | (setq image | |
9bb7a286 DL |
314 | (cons 'image (plist-put (copy-sequence spec) |
315 | :file found)))))) | |
f64ae86c | 316 | ((not (null data)) |
162dec01 GM |
317 | (setq image (cons 'image spec))))) |
318 | (setq specs (cdr specs)))) | |
349c034d GM |
319 | image)) |
320 | ||
321 | ||
322 | ;;;###autoload | |
323 | (defmacro defimage (symbol specs &optional doc) | |
324 | "Define SYMBOL as an image. | |
325 | ||
326 | SPECS is a list of image specifications. DOC is an optional | |
327 | documentation string. | |
328 | ||
329 | Each image specification in SPECS is a property list. The contents of | |
330 | a specification are image type dependent. All specifications must at | |
331 | least contain the properties `:type TYPE' and either `:file FILE' or | |
332 | `:data DATA', where TYPE is a symbol specifying the image type, | |
333 | e.g. `xbm', FILE is the file to load the image from, and DATA is a | |
334 | string containing the actual image data. The first image | |
335 | specification whose TYPE is supported, and FILE exists, is used to | |
336 | define SYMBOL. | |
337 | ||
338 | Example: | |
339 | ||
340 | (defimage test-image ((:type xpm :file \"~/test1.xpm\") | |
341 | (:type xbm :file \"~/test1.xbm\")))" | |
342 | `(defvar ,symbol (find-image ',specs) ,doc)) | |
7840ced1 GM |
343 | |
344 | ||
345 | (provide 'image) | |
346 | ||
ab5796a9 | 347 | ;;; arch-tag: 8e76a07b-eb48-4f3e-a7a0-1a7ba9f096b3 |
e43367a0 | 348 | ;;; image.el ends here |