1;;; image.el --- image API 2 3;; Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 4;; 2004, 2005, 2006, 2007 Free Software Foundation, Inc. 5 6;; Maintainer: FSF 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 2, or (at your option) 14;; 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; see the file COPYING. If not, write to the 23;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 24;; Boston, MA 02110-1301, USA. 25 26;;; Commentary: 27 28;;; Code: 29 30 31(defgroup image () 32 "Image support." 33 :group 'multimedia) 34 35 36(defconst image-type-header-regexps 37 '(("\\`/[\t\n\r ]*\\*.*XPM.\\*/" . xpm) 38 ("\\`P[1-6][[:space:]]+\\(?:#.*[[:space:]]+\\)*[0-9]+[[:space:]]+[0-9]+" . pbm) 39 ("\\`GIF8[79]a" . gif) 40 ("\\`\x89PNG\r\n\x1a\n" . png) 41 ("\\`[\t\n\r ]*#define \\([a-z0-9]+\\)_width [0-9]+\n\ 42#define \\1_height [0-9]+\n\ 43static char \\1_bits" . xbm) 44 ("\\`\\(?:MM\0\\*\\|II\\*\0\\)" . tiff) 45 ("\\`[\t\n\r ]*%!PS" . postscript) 46 ("\\`\xff\xd8" . (image-jpeg-p . jpeg))) 47 "Alist of (REGEXP . IMAGE-TYPE) pairs used to auto-detect image types. 48When the first bytes of an image file match REGEXP, it is assumed to 49be of image type IMAGE-TYPE if IMAGE-TYPE is a symbol. If not a symbol, 50IMAGE-TYPE must be a pair (PREDICATE . TYPE). PREDICATE is called 51with one argument, a string containing the image data. If PREDICATE returns 52a non-nil value, TYPE is the image's type.") 53 54(defconst image-type-file-name-regexps 55 '(("\\.png\\'" . png) 56 ("\\.gif\\'" . gif) 57 ("\\.jpe?g\\'" . jpeg) 58 ("\\.bmp\\'" . bmp) 59 ("\\.xpm\\'" . xpm) 60 ("\\.pbm\\'" . pbm) 61 ("\\.xbm\\'" . xbm) 62 ("\\.ps\\'" . postscript) 63 ("\\.tiff?\\'" . tiff)) 64 "Alist of (REGEXP . IMAGE-TYPE) pairs used to identify image files. 65When the name of an image file match REGEXP, it is assumed to 66be of image type IMAGE-TYPE.") 67 68;; We rely on `auto-mode-alist' to detect xbm and xpm files, instead 69;; of content autodetection. Their contents are just C code, so it is 70;; easy to generate false matches. 71(defvar image-type-auto-detectable 72 '((pbm . t) 73 (xbm . nil) 74 (bmp . maybe) 75 (gif . maybe) 76 (png . maybe) 77 (xpm . nil) 78 (jpeg . maybe) 79 (tiff . maybe) 80 (postscript . nil)) 81 "Alist of (IMAGE-TYPE . AUTODETECT) pairs used to auto-detect image files. 82\(See `image-type-auto-detected-p'). 83 84AUTODETECT can be 85 - t always auto-detect. 86 - nil never auto-detect. 87 - maybe auto-detect only if the image type is available 88 (see `image-type-available-p').") 89 90(defvar image-load-path nil 91 "List of locations in which to search for image files. 92If an element is a string, it defines a directory to search. 93If an element is a variable symbol whose value is a string, that 94value defines a directory to search. 95If an element is a variable symbol whose value is a list, the 96value is used as a list of directories to search.") 97 98(eval-at-startup 99 (setq image-load-path 100 (list (file-name-as-directory (expand-file-name "images" data-directory)) 101 'data-directory 'load-path))) 102 103 104(defun image-load-path-for-library (library image &optional path no-error) 105 "Return a suitable search path for images used by LIBRARY. 106 107It searches for IMAGE in `image-load-path' (excluding 108\"`data-directory'/images\") and `load-path', followed by a path 109suitable for LIBRARY, which includes \"../../etc/images\" and 110\"../etc/images\" relative to the library file itself, and then 111in \"`data-directory'/images\". 112 113Then this function returns a list of directories which contains 114first the directory in which IMAGE was found, followed by the 115value of `load-path'. If PATH is given, it is used instead of 116`load-path'. 117 118If NO-ERROR is non-nil and a suitable path can't be found, don't 119signal an error. Instead, return a list of directories as before, 120except that nil appears in place of the image directory. 121 122Here is an example that uses a common idiom to provide 123compatibility with versions of Emacs that lack the variable 124`image-load-path': 125 126 ;; Shush compiler. 127 (defvar image-load-path) 128 129 (let* ((load-path (image-load-path-for-library \"mh-e\" \"mh-logo.xpm\")) 130 (image-load-path (cons (car load-path) 131 (when (boundp 'image-load-path) 132 image-load-path)))) 133 (mh-tool-bar-folder-buttons-init))" 134 (unless library (error "No library specified")) 135 (unless image (error "No image specified")) 136 (let (image-directory image-directory-load-path) 137 ;; Check for images in image-load-path or load-path. 138 (let ((img image) 139 (dir (or 140 ;; Images in image-load-path. 141 (image-search-load-path image) 142 ;; Images in load-path. 143 (locate-library image))) 144 parent) 145 ;; Since the image might be in a nested directory (for 146 ;; example, mail/attach.pbm), adjust `image-directory' 147 ;; accordingly. 148 (when dir 149 (setq dir (file-name-directory dir)) 150 (while (setq parent (file-name-directory img)) 151 (setq img (directory-file-name parent) 152 dir (expand-file-name "../" dir)))) 153 (setq image-directory-load-path dir)) 154 155 ;; If `image-directory-load-path' isn't Emacs' image directory, 156 ;; it's probably a user preference, so use it. Then use a 157 ;; relative setting if possible; otherwise, use 158 ;; `image-directory-load-path'. 159 (cond 160 ;; User-modified image-load-path? 161 ((and image-directory-load-path 162 (not (equal image-directory-load-path 163 (file-name-as-directory 164 (expand-file-name "images" data-directory))))) 165 (setq image-directory image-directory-load-path)) 166 ;; Try relative setting. 167 ((let (library-name d1ei d2ei) 168 ;; First, find library in the load-path. 169 (setq library-name (locate-library library)) 170 (if (not library-name) 171 (error "Cannot find library %s in load-path" library)) 172 ;; And then set image-directory relative to that. 173 (setq 174 ;; Go down 2 levels. 175 d2ei (file-name-as-directory 176 (expand-file-name 177 (concat (file-name-directory library-name) "../../etc/images"))) 178 ;; Go down 1 level. 179 d1ei (file-name-as-directory 180 (expand-file-name 181 (concat (file-name-directory library-name) "../etc/images")))) 182 (setq image-directory 183 ;; Set it to nil if image is not found. 184 (cond ((file-exists-p (expand-file-name image d2ei)) d2ei) 185 ((file-exists-p (expand-file-name image d1ei)) d1ei))))) 186 ;; Use Emacs' image directory. 187 (image-directory-load-path 188 (setq image-directory image-directory-load-path)) 189 (no-error 190 (message "Could not find image %s for library %s" image library)) 191 (t 192 (error "Could not find image %s for library %s" image library))) 193 194 ;; Return an augmented `path' or `load-path'. 195 (nconc (list image-directory) 196 (delete image-directory (copy-sequence (or path load-path)))))) 197 198 199(defun image-jpeg-p (data) 200 "Value is non-nil if DATA, a string, consists of JFIF image data. 201We accept the tag Exif because that is the same format." 202 (when (string-match "\\`\xff\xd8" data) 203 (catch 'jfif 204 (let ((len (length data)) (i 2)) 205 (while (< i len) 206 (when (/= (aref data i) #xff) 207 (throw 'jfif nil)) 208 (setq i (1+ i)) 209 (when (>= (+ i 2) len) 210 (throw 'jfif nil)) 211 (let ((nbytes (+ (lsh (aref data (+ i 1)) 8) 212 (aref data (+ i 2)))) 213 (code (aref data i))) 214 (when (and (>= code #xe0) (<= code #xef)) 215 ;; APP0 LEN1 LEN2 "JFIF\0" 216 (throw 'jfif 217 (string-match "JFIF\\|Exif" 218 (substring data i (min (+ i nbytes) len))))) 219 (setq i (+ i 1 nbytes)))))))) 220 221 222;;;###autoload 223(defun image-type-from-data (data) 224 "Determine the image type from image data DATA. 225Value is a symbol specifying the image type or nil if type cannot 226be determined." 227 (let ((types image-type-header-regexps) 228 type) 229 (while types 230 (let ((regexp (car (car types))) 231 (image-type (cdr (car types)))) 232 (if (or (and (symbolp image-type) 233 (string-match regexp data)) 234 (and (consp image-type) 235 (funcall (car image-type) data) 236 (setq image-type (cdr image-type)))) 237 (setq type image-type 238 types nil) 239 (setq types (cdr types))))) 240 type)) 241 242 243;;;###autoload 244(defun image-type-from-buffer () 245 "Determine the image type from data in the current buffer. 246Value is a symbol specifying the image type or nil if type cannot 247be determined." 248 (let ((types image-type-header-regexps) 249 type 250 (opoint (point))) 251 (goto-char (point-min)) 252 (while types 253 (let ((regexp (car (car types))) 254 (image-type (cdr (car types))) 255 data) 256 (if (or (and (symbolp image-type) 257 (looking-at regexp)) 258 (and (consp image-type) 259 (funcall (car image-type) 260 (or data 261 (setq data 262 (buffer-substring 263 (point-min) 264 (min (point-max) 265 (+ (point-min) 256)))))) 266 (setq image-type (cdr image-type)))) 267 (setq type image-type 268 types nil) 269 (setq types (cdr types))))) 270 (goto-char opoint) 271 type)) 272 273 274;;;###autoload 275(defun image-type-from-file-header (file) 276 "Determine the type of image file FILE from its first few bytes. 277Value is a symbol specifying the image type, or nil if type cannot 278be determined." 279 (unless (or (file-readable-p file) 280 (file-name-absolute-p file)) 281 (setq file (image-search-load-path file))) 282 (and file 283 (file-readable-p file) 284 (with-temp-buffer 285 (set-buffer-multibyte nil) 286 (insert-file-contents-literally file nil 0 256) 287 (image-type-from-buffer)))) 288 289 290;;;###autoload 291(defun image-type-from-file-name (file) 292 "Determine the type of image file FILE from its name. 293Value is a symbol specifying the image type, or nil if type cannot 294be determined." 295 (let ((types image-type-file-name-regexps) 296 type) 297 (while types 298 (if (string-match (car (car types)) file) 299 (setq type (cdr (car types)) 300 types nil) 301 (setq types (cdr types)))) 302 type)) 303 304 305;;;###autoload 306(defun image-type (file-or-data &optional type data-p) 307 "Determine and return image type. 308FILE-OR-DATA is an image file name or image data. 309Optional TYPE is a symbol describing the image type. If TYPE is omitted 310or nil, try to determine the image type from its first few bytes 311of image data. If that doesn't work, and FILE-OR-DATA is a file name, 312use its file extension as image type. 313Optional DATA-P non-nil means FILE-OR-DATA is a string containing image data." 314 (when (and (not data-p) (not (stringp file-or-data))) 315 (error "Invalid image file name `%s'" file-or-data)) 316 (cond ((null data-p) 317 ;; FILE-OR-DATA is a file name. 318 (unless (or type 319 (setq type (image-type-from-file-header file-or-data))) 320 (let ((extension (file-name-extension file-or-data))) 321 (unless extension 322 (error "Cannot determine image type")) 323 (setq type (intern extension))))) 324 (t 325 ;; FILE-OR-DATA contains image data. 326 (unless type 327 (setq type (image-type-from-data file-or-data))))) 328 (unless type 329 (error "Cannot determine image type")) 330 (unless (symbolp type) 331 (error "Invalid image type `%s'" type)) 332 type) 333 334 335;;;###autoload 336(defun image-type-available-p (type) 337 "Return non-nil if image type TYPE is available. 338Image types are symbols like `xbm' or `jpeg'." 339 (and (fboundp 'init-image-library) 340 (init-image-library type image-library-alist))) 341 342 343;;;###autoload 344(defun image-type-auto-detected-p () 345 "Return t iff the current buffer contains an auto-detectable image. 346This function is intended to be used from `magic-mode-alist' (which see). 347 348First, compare the beginning of the buffer with `image-type-header-regexps'. 349If an appropriate image type is found, check if that image type can be 350autodetected using the variable `image-type-auto-detectable'. Finally, 351if `buffer-file-name' is non-nil, check if it matches another major mode 352in `auto-mode-alist' apart from `image-mode'; if there is another match, 353the autodetection is considered to have failed. Return t if all the above 354steps succeed." 355 (let* ((type (image-type-from-buffer)) 356 (auto (and type (cdr (assq type image-type-auto-detectable))))) 357 (and auto 358 (or (eq auto t) (image-type-available-p type)) 359 (or (null buffer-file-name) 360 (not (assoc-default 361 buffer-file-name 362 (delq nil (mapcar 363 (lambda (elt) 364 (unless (memq (or (car-safe (cdr elt)) 365 (cdr elt)) 366 '(image-mode image-mode-maybe)) 367 elt)) 368 auto-mode-alist)) 369 'string-match)))))) 370 371 372;;;###autoload 373(defun create-image (file-or-data &optional type data-p &rest props) 374 "Create an image. 375FILE-OR-DATA is an image file name or image data. 376Optional TYPE is a symbol describing the image type. If TYPE is omitted 377or nil, try to determine the image type from its first few bytes 378of image data. If that doesn't work, and FILE-OR-DATA is a file name, 379use its file extension as image type. 380Optional DATA-P non-nil means FILE-OR-DATA is a string containing image data. 381Optional PROPS are additional image attributes to assign to the image, 382like, e.g. `:mask MASK'. 383Value is the image created, or nil if images of type TYPE are not supported. 384 385Images should not be larger than specified by `max-image-size'." 386 (setq type (image-type file-or-data type data-p)) 387 (when (image-type-available-p type) 388 (append (list 'image :type type (if data-p :data :file) file-or-data) 389 props))) 390 391 392;;;###autoload 393(defun put-image (image pos &optional string area) 394 "Put image IMAGE in front of POS in the current buffer. 395IMAGE must be an image created with `create-image' or `defimage'. 396IMAGE is displayed by putting an overlay into the current buffer with a 397`before-string' STRING that has a `display' property whose value is the 398image. STRING is defaulted if you omit it. 399POS may be an integer or marker. 400AREA is where to display the image. AREA nil or omitted means 401display it in the text area, a value of `left-margin' means 402display it in the left marginal area, a value of `right-margin' 403means display it in the right marginal area." 404 (unless string (setq string "x")) 405 (let ((buffer (current-buffer))) 406 (unless (eq (car-safe image) 'image) 407 (error "Not an image: %s" image)) 408 (unless (or (null area) (memq area '(left-margin right-margin))) 409 (error "Invalid area %s" area)) 410 (setq string (copy-sequence string)) 411 (let ((overlay (make-overlay pos pos buffer)) 412 (prop (if (null area) image (list (list 'margin area) image)))) 413 (put-text-property 0 (length string) 'display prop string) 414 (overlay-put overlay 'put-image t) 415 (overlay-put overlay 'before-string string)))) 416 417 418;;;###autoload 419(defun insert-image (image &optional string area slice) 420 "Insert IMAGE into current buffer at point. 421IMAGE is displayed by inserting STRING into the current buffer 422with a `display' property whose value is the image. STRING is 423defaulted if you omit it. 424AREA is where to display the image. AREA nil or omitted means 425display it in the text area, a value of `left-margin' means 426display it in the left marginal area, a value of `right-margin' 427means display it in the right marginal area. 428SLICE specifies slice of IMAGE to insert. SLICE nil or omitted 429means insert whole image. SLICE is a list (X Y WIDTH HEIGHT) 430specifying the X and Y positions and WIDTH and HEIGHT of image area 431to insert. A float value 0.0 - 1.0 means relative to the width or 432height of the image; integer values are taken as pixel values." 433 ;; Use a space as least likely to cause trouble when it's a hidden 434 ;; character in the buffer. 435 (unless string (setq string " ")) 436 (unless (eq (car-safe image) 'image) 437 (error "Not an image: %s" image)) 438 (unless (or (null area) (memq area '(left-margin right-margin))) 439 (error "Invalid area %s" area)) 440 (if area 441 (setq image (list (list 'margin area) image)) 442 ;; Cons up a new spec equal but not eq to `image' so that 443 ;; inserting it twice in a row (adjacently) displays two copies of 444 ;; the image. Don't try to avoid this by looking at the display 445 ;; properties on either side so that we DTRT more often with 446 ;; cut-and-paste. (Yanking killed image text next to another copy 447 ;; of it loses anyway.) 448 (setq image (cons 'image (cdr image)))) 449 (let ((start (point))) 450 (insert string) 451 (add-text-properties start (point) 452 `(display ,(if slice 453 (list (cons 'slice slice) image) 454 image) rear-nonsticky (display))))) 455 456 457;;;###autoload 458(defun insert-sliced-image (image &optional string area rows cols) 459 "Insert IMAGE into current buffer at point. 460IMAGE is displayed by inserting STRING into the current buffer 461with a `display' property whose value is the image. STRING is 462defaulted if you omit it. 463AREA is where to display the image. AREA nil or omitted means 464display it in the text area, a value of `left-margin' means 465display it in the left marginal area, a value of `right-margin' 466means display it in the right marginal area. 467The image is automatically split into ROW x COLS slices." 468 (unless string (setq string " ")) 469 (unless (eq (car-safe image) 'image) 470 (error "Not an image: %s" image)) 471 (unless (or (null area) (memq area '(left-margin right-margin))) 472 (error "Invalid area %s" area)) 473 (if area 474 (setq image (list (list 'margin area) image)) 475 ;; Cons up a new spec equal but not eq to `image' so that 476 ;; inserting it twice in a row (adjacently) displays two copies of 477 ;; the image. Don't try to avoid this by looking at the display 478 ;; properties on either side so that we DTRT more often with 479 ;; cut-and-paste. (Yanking killed image text next to another copy 480 ;; of it loses anyway.) 481 (setq image (cons 'image (cdr image)))) 482 (let ((x 0.0) (dx (/ 1.0001 (or cols 1))) 483 (y 0.0) (dy (/ 1.0001 (or rows 1)))) 484 (while (< y 1.0) 485 (while (< x 1.0) 486 (let ((start (point))) 487 (insert string) 488 (add-text-properties start (point) 489 `(display ,(list (list 'slice x y dx dy) image) 490 rear-nonsticky (display))) 491 (setq x (+ x dx)))) 492 (setq x 0.0 493 y (+ y dy)) 494 (insert (propertize "\n" 'line-height t))))) 495 496 497 498;;;###autoload 499(defun remove-images (start end &optional buffer) 500 "Remove images between START and END in BUFFER. 501Remove only images that were put in BUFFER with calls to `put-image'. 502BUFFER nil or omitted means use the current buffer." 503 (unless buffer 504 (setq buffer (current-buffer))) 505 (let ((overlays (overlays-in start end))) 506 (while overlays 507 (let ((overlay (car overlays))) 508 (when (overlay-get overlay 'put-image) 509 (delete-overlay overlay))) 510 (setq overlays (cdr overlays))))) 511 512(defun image-search-load-path (file &optional path) 513 (unless path 514 (setq path image-load-path)) 515 (let (element found filename) 516 (while (and (not found) (consp path)) 517 (setq element (car path)) 518 (cond 519 ((stringp element) 520 (setq found 521 (file-readable-p 522 (setq filename (expand-file-name file element))))) 523 ((and (symbolp element) (boundp element)) 524 (setq element (symbol-value element)) 525 (cond 526 ((stringp element) 527 (setq found 528 (file-readable-p 529 (setq filename (expand-file-name file element))))) 530 ((consp element) 531 (if (setq filename (image-search-load-path file element)) 532 (setq found t)))))) 533 (setq path (cdr path))) 534 (if found filename))) 535 536;;;###autoload 537(defun find-image (specs) 538 "Find an image, choosing one of a list of image specifications. 539 540SPECS is a list of image specifications. 541 542Each image specification in SPECS is a property list. The contents of 543a specification are image type dependent. All specifications must at 544least contain the properties `:type TYPE' and either `:file FILE' or 545`:data DATA', where TYPE is a symbol specifying the image type, 546e.g. `xbm', FILE is the file to load the image from, and DATA is a 547string containing the actual image data. The specification whose TYPE 548is supported, and FILE exists, is used to construct the image 549specification to be returned. Return nil if no specification is 550satisfied. 551 552The image is looked for in `image-load-path'. 553 554Image files should not be larger than specified by `max-image-size'." 555 (let (image) 556 (while (and specs (null image)) 557 (let* ((spec (car specs)) 558 (type (plist-get spec :type)) 559 (data (plist-get spec :data)) 560 (file (plist-get spec :file)) 561 found) 562 (when (image-type-available-p type) 563 (cond ((stringp file) 564 (if (setq found (image-search-load-path file)) 565 (setq image 566 (cons 'image (plist-put (copy-sequence spec) 567 :file found))))) 568 ((not (null data)) 569 (setq image (cons 'image spec))))) 570 (setq specs (cdr specs)))) 571 image)) 572 573 574;;;###autoload 575(defmacro defimage (symbol specs &optional doc) 576 "Define SYMBOL as an image. 577 578SPECS is a list of image specifications. DOC is an optional 579documentation string. 580 581Each image specification in SPECS is a property list. The contents of 582a specification are image type dependent. All specifications must at 583least contain the properties `:type TYPE' and either `:file FILE' or 584`:data DATA', where TYPE is a symbol specifying the image type, 585e.g. `xbm', FILE is the file to load the image from, and DATA is a 586string containing the actual image data. The first image 587specification whose TYPE is supported, and FILE exists, is used to 588define SYMBOL. 589 590Example: 591 592 (defimage test-image ((:type xpm :file \"~/test1.xpm\") 593 (:type xbm :file \"~/test1.xbm\")))" 594 (declare (doc-string 3)) 595 `(defvar ,symbol (find-image ',specs) ,doc)) 596 597 598(provide 'image) 599 600;; arch-tag: 8e76a07b-eb48-4f3e-a7a0-1a7ba9f096b3 601;;; image.el ends here 602