lisp/image.el

   1 ;;; image.el --- image API
   2
   3 ;; Copyright (C) 1998-2014 Free Software Foundation, Inc.
   4
   5 ;; Maintainer: FSF
   6 ;; Keywords: multimedia
   7 ;; Package: emacs
   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 ;;; Code:
  27
  28
  29 (defgroup image ()
  30   "Image support."
  31   :group 'multimedia)
  32
  33 (defalias 'image-refresh 'image-flush)
  34
  35 (defconst image-type-header-regexps
  36   `(("\\`/[\t\n\r ]*\\*.*XPM.\\*/" . xpm)
  37     ("\\`P[1-6]\\\(?:\
  38 \\(?:\\(?:#[^\r\n]*[\r\n]\\)?[[:space:]]\\)+\
  39 \\(?:\\(?:#[^\r\n]*[\r\n]\\)?[0-9]\\)+\
  40 \\)\\{2\\}" . pbm)
  41     ("\\`GIF8[79]a" . gif)
  42     ("\\`\x89PNG\r\n\x1a\n" . png)
  43     ("\\`[\t\n\r ]*#define \\([a-z0-9_]+\\)_width [0-9]+\n\
  44 #define \\1_height [0-9]+\n\\(\
  45 #define \\1_x_hot [0-9]+\n\
  46 #define \\1_y_hot [0-9]+\n\\)?\
  47 static \\(unsigned \\)?char \\1_bits" . xbm)
  48     ("\\`\\(?:MM\0\\*\\|II\\*\0\\)" . tiff)
  49     ("\\`[\t\n\r ]*%!PS" . postscript)
  50     ("\\`\xff\xd8" . jpeg)    ; used to be (image-jpeg-p . jpeg)
  51     (,(let* ((incomment-re "\\(?:[^-]\\|-[^-]\\)")
  52              (comment-re (concat "\\(?:!--" incomment-re "*-->[ \t\r\n]*<\\)")))
  53         (concat "\\(?:<\\?xml[ \t\r\n]+[^>]*>\\)?[ \t\r\n]*<"
  54                 comment-re "*"
  55                 "\\(?:!DOCTYPE[ \t\r\n]+[^>]*>[ \t\r\n]*<[ \t\r\n]*" comment-re "*\\)?"
  56                 "[Ss][Vv][Gg]"))
  57      . svg)
  58     )
  59   "Alist of (REGEXP . IMAGE-TYPE) pairs used to auto-detect image types.
  60 When the first bytes of an image file match REGEXP, it is assumed to
  61 be of image type IMAGE-TYPE if IMAGE-TYPE is a symbol.  If not a symbol,
  62 IMAGE-TYPE must be a pair (PREDICATE . TYPE).  PREDICATE is called
  63 with one argument, a string containing the image data.  If PREDICATE returns
  64 a non-nil value, TYPE is the image's type.")
  65
  66 (defvar image-type-file-name-regexps
  67   '(("\\.png\\'" . png)
  68     ("\\.gif\\'" . gif)
  69     ("\\.jpe?g\\'" . jpeg)
  70     ("\\.bmp\\'" . bmp)
  71     ("\\.xpm\\'" . xpm)
  72     ("\\.pbm\\'" . pbm)
  73     ("\\.xbm\\'" . xbm)
  74     ("\\.ps\\'" . postscript)
  75     ("\\.tiff?\\'" . tiff)
  76     ("\\.svgz?\\'" . svg)
  77     )
  78   "Alist of (REGEXP . IMAGE-TYPE) pairs used to identify image files.
  79 When the name of an image file match REGEXP, it is assumed to
  80 be of image type IMAGE-TYPE.")
  81
  82 ;; We rely on `auto-mode-alist' to detect xbm and xpm files, instead
  83 ;; of content autodetection.  Their contents are just C code, so it is
  84 ;; easy to generate false matches.
  85 (defvar image-type-auto-detectable
  86   '((pbm . t)
  87     (xbm . nil)
  88     (bmp . maybe)
  89     (gif . maybe)
  90     (png . maybe)
  91     (xpm . nil)
  92     (jpeg . maybe)
  93     (tiff . maybe)
  94     (svg . maybe)
  95     (postscript . nil))
  96   "Alist of (IMAGE-TYPE . AUTODETECT) pairs used to auto-detect image files.
  97 \(See `image-type-auto-detected-p').
  98
  99 AUTODETECT can be
 100  - t      always auto-detect.
 101  - nil    never auto-detect.
 102  - maybe  auto-detect only if the image type is available
 103             (see `image-type-available-p').")
 104
 105 (defvar image-format-suffixes
 106   '((image/x-icon "ico"))
 107   "Alist of MIME Content-Type headers to file name suffixes.
 108 This is used as a hint by the ImageMagick library when detecting
 109 image types.  If `create-image' is called with a :format
 110 matching found in this alist, the ImageMagick library will be
 111 told that the data would have this suffix if saved to a file.")
 112
 113 (defcustom image-load-path
 114   (list (file-name-as-directory (expand-file-name "images" data-directory))
 115         'data-directory 'load-path)
 116   "List of locations in which to search for image files.
 117 If an element is a string, it defines a directory to search.
 118 If an element is a variable symbol whose value is a string, that
 119 value defines a directory to search.
 120 If an element is a variable symbol whose value is a list, the
 121 value is used as a list of directories to search.
 122
 123 Subdirectories are not automatically included in the search."
 124   :type '(repeat (choice directory variable))
 125   :initialize 'custom-initialize-delay)
 126
 127
 128 (defun image-load-path-for-library (library image &optional path no-error)
 129   "Return a suitable search path for images used by LIBRARY.
 130
 131 It searches for IMAGE in `image-load-path' (excluding
 132 \"`data-directory'/images\") and `load-path', followed by a path
 133 suitable for LIBRARY, which includes \"../../etc/images\" and
 134 \"../etc/images\" relative to the library file itself, and then
 135 in \"`data-directory'/images\".
 136
 137 Then this function returns a list of directories which contains
 138 first the directory in which IMAGE was found, followed by the
 139 value of `load-path'.  If PATH is given, it is used instead of
 140 `load-path'.
 141
 142 If NO-ERROR is non-nil and a suitable path can't be found, don't
 143 signal an error.  Instead, return a list of directories as before,
 144 except that nil appears in place of the image directory.
 145
 146 Here is an example that uses a common idiom to provide
 147 compatibility with versions of Emacs that lack the variable
 148 `image-load-path':
 149
 150     ;; Shush compiler.
 151     (defvar image-load-path)
 152
 153     (let* ((load-path (image-load-path-for-library \"mh-e\" \"mh-logo.xpm\"))
 154            (image-load-path (cons (car load-path)
 155                                   (when (boundp 'image-load-path)
 156                                     image-load-path))))
 157       (mh-tool-bar-folder-buttons-init))"
 158   (unless library (error "No library specified"))
 159   (unless image   (error "No image specified"))
 160   (let (image-directory image-directory-load-path)
 161     ;; Check for images in image-load-path or load-path.
 162     (let ((img image)
 163           (dir (or
 164                 ;; Images in image-load-path.
 165                 (image-search-load-path image)
 166                 ;; Images in load-path.
 167                 (locate-library image)))
 168           parent)
 169       ;; Since the image might be in a nested directory (for
 170       ;; example, mail/attach.pbm), adjust `image-directory'
 171       ;; accordingly.
 172       (when dir
 173         (setq dir (file-name-directory dir))
 174         (while (setq parent (file-name-directory img))
 175           (setq img (directory-file-name parent)
 176                 dir (expand-file-name "../" dir))))
 177       (setq image-directory-load-path dir))
 178
 179     ;; If `image-directory-load-path' isn't Emacs's image directory,
 180     ;; it's probably a user preference, so use it. Then use a
 181     ;; relative setting if possible; otherwise, use
 182     ;; `image-directory-load-path'.
 183     (cond
 184      ;; User-modified image-load-path?
 185      ((and image-directory-load-path
 186            (not (equal image-directory-load-path
 187                        (file-name-as-directory
 188                         (expand-file-name "images" data-directory)))))
 189       (setq image-directory image-directory-load-path))
 190      ;; Try relative setting.
 191      ((let (library-name d1ei d2ei)
 192         ;; First, find library in the load-path.
 193         (setq library-name (locate-library library))
 194         (if (not library-name)
 195             (error "Cannot find library %s in load-path" library))
 196         ;; And then set image-directory relative to that.
 197         (setq
 198          ;; Go down 2 levels.
 199          d2ei (file-name-as-directory
 200                (expand-file-name
 201                 (concat (file-name-directory library-name) "../../etc/images")))
 202          ;; Go down 1 level.
 203          d1ei (file-name-as-directory
 204                (expand-file-name
 205                 (concat (file-name-directory library-name) "../etc/images"))))
 206         (setq image-directory
 207               ;; Set it to nil if image is not found.
 208               (cond ((file-exists-p (expand-file-name image d2ei)) d2ei)
 209                     ((file-exists-p (expand-file-name image d1ei)) d1ei)))))
 210      ;; Use Emacs's image directory.
 211      (image-directory-load-path
 212       (setq image-directory image-directory-load-path))
 213      (no-error
 214       (message "Could not find image %s for library %s" image library))
 215      (t
 216       (error "Could not find image %s for library %s" image library)))
 217
 218     ;; Return an augmented `path' or `load-path'.
 219     (nconc (list image-directory)
 220            (delete image-directory (copy-sequence (or path load-path))))))
 221
 222
 223 ;; Used to be in image-type-header-regexps, but now not used anywhere
 224 ;; (since 2009-08-28).
 225 (defun image-jpeg-p (data)
 226   "Value is non-nil if DATA, a string, consists of JFIF image data.
 227 We accept the tag Exif because that is the same format."
 228   (setq data (ignore-errors (string-to-unibyte data)))
 229   (when (and data (string-match-p "\\`\xff\xd8" data))
 230     (catch 'jfif
 231       (let ((len (length data)) (i 2))
 232         (while (< i len)
 233           (when (/= (aref data i) #xff)
 234             (throw 'jfif nil))
 235           (setq i (1+ i))
 236           (when (>= (+ i 2) len)
 237             (throw 'jfif nil))
 238           (let ((nbytes (+ (lsh (aref data (+ i 1)) 8)
 239                            (aref data (+ i 2))))
 240                 (code (aref data i)))
 241             (when (and (>= code #xe0) (<= code #xef))
 242               ;; APP0 LEN1 LEN2 "JFIF\0"
 243               (throw 'jfif
 244                      (string-match-p "JFIF\\|Exif"
 245                                      (substring data i (min (+ i nbytes) len)))))
 246             (setq i (+ i 1 nbytes))))))))
 247
 248
 249 ;;;###autoload
 250 (defun image-type-from-data (data)
 251   "Determine the image type from image data DATA.
 252 Value is a symbol specifying the image type or nil if type cannot
 253 be determined."
 254   (let ((types image-type-header-regexps)
 255         type)
 256     (while types
 257       (let ((regexp (car (car types)))
 258             (image-type (cdr (car types))))
 259         (if (or (and (symbolp image-type)
 260                      (string-match-p regexp data))
 261                 (and (consp image-type)
 262                      (funcall (car image-type) data)
 263                      (setq image-type (cdr image-type))))
 264             (setq type image-type
 265                   types nil)
 266           (setq types (cdr types)))))
 267     type))
 268
 269
 270 ;;;###autoload
 271 (defun image-type-from-buffer ()
 272   "Determine the image type from data in the current buffer.
 273 Value is a symbol specifying the image type or nil if type cannot
 274 be determined."
 275   (let ((types image-type-header-regexps)
 276         type
 277         (opoint (point)))
 278     (goto-char (point-min))
 279     (while types
 280       (let ((regexp (car (car types)))
 281             (image-type (cdr (car types)))
 282             data)
 283         (if (or (and (symbolp image-type)
 284                      (looking-at-p regexp))
 285                 (and (consp image-type)
 286                      (funcall (car image-type)
 287                               (or data
 288                                   (setq data
 289                                         (buffer-substring
 290                                          (point-min)
 291                                          (min (point-max)
 292                                               (+ (point-min) 256))))))
 293                      (setq image-type (cdr image-type))))
 294             (setq type image-type
 295                   types nil)
 296           (setq types (cdr types)))))
 297     (goto-char opoint)
 298     (and type
 299          (boundp 'image-types)
 300          (memq type image-types)
 301          type)))
 302
 303
 304 ;;;###autoload
 305 (defun image-type-from-file-header (file)
 306   "Determine the type of image file FILE from its first few bytes.
 307 Value is a symbol specifying the image type, or nil if type cannot
 308 be determined."
 309   (unless (or (file-readable-p file)
 310               (file-name-absolute-p file))
 311     (setq file (image-search-load-path file)))
 312   (and file
 313        (file-readable-p file)
 314        (with-temp-buffer
 315          (set-buffer-multibyte nil)
 316          (insert-file-contents-literally file nil 0 256)
 317          (image-type-from-buffer))))
 318
 319
 320 ;;;###autoload
 321 (defun image-type-from-file-name (file)
 322   "Determine the type of image file FILE from its name.
 323 Value is a symbol specifying the image type, or nil if type cannot
 324 be determined."
 325   (let (type first)
 326     (catch 'found
 327       (dolist (elem image-type-file-name-regexps first)
 328         (when (string-match-p (car elem) file)
 329           (if (image-type-available-p (setq type (cdr elem)))
 330               (throw 'found type)
 331             ;; If nothing seems to be supported, return first type that matched.
 332             (or first (setq first type))))))))
 333
 334 ;;;###autoload
 335 (defun image-type (source &optional type data-p)
 336   "Determine and return image type.
 337 SOURCE is an image file name or image data.
 338 Optional TYPE is a symbol describing the image type.  If TYPE is omitted
 339 or nil, try to determine the image type from its first few bytes
 340 of image data.  If that doesn't work, and SOURCE is a file name,
 341 use its file extension as image type.
 342 Optional DATA-P non-nil means SOURCE is a string containing image data."
 343   (when (and (not data-p) (not (stringp source)))
 344     (error "Invalid image file name `%s'" source))
 345   (unless type
 346     (setq type (if data-p
 347                    (image-type-from-data source)
 348                  (or (image-type-from-file-header source)
 349                      (image-type-from-file-name source))))
 350     (or type (error "Cannot determine image type")))
 351   (or (memq type (and (boundp 'image-types) image-types))
 352       (error "Invalid image type `%s'" type))
 353   type)
 354
 355
 356 (if (fboundp 'image-metadata)           ; eg not --without-x
 357     (define-obsolete-function-alias 'image-extension-data
 358       'image-metadata' "24.1"))
 359
 360 (define-obsolete-variable-alias
 361     'image-library-alist
 362     'dynamic-library-alist "24.1")
 363
 364 ;;;###autoload
 365 (defun image-type-available-p (type)
 366   "Return non-nil if image type TYPE is available.
 367 Image types are symbols like `xbm' or `jpeg'."
 368   (and (fboundp 'init-image-library)
 369        (init-image-library type)))
 370
 371
 372 ;;;###autoload
 373 (defun image-type-auto-detected-p ()
 374   "Return t if the current buffer contains an auto-detectable image.
 375 This function is intended to be used from `magic-fallback-mode-alist'.
 376
 377 The buffer is considered to contain an auto-detectable image if
 378 its beginning matches an image type in `image-type-header-regexps',
 379 and that image type is present in `image-type-auto-detectable' with a
 380 non-nil value.  If that value is non-nil, but not t, then the image type
 381 must be available."
 382   (let* ((type (image-type-from-buffer))
 383          (auto (and type (cdr (assq type image-type-auto-detectable)))))
 384     (and auto
 385          (or (eq auto t) (image-type-available-p type)))))
 386
 387
 388 ;;;###autoload
 389 (defun create-image (file-or-data &optional type data-p &rest props)
 390   "Create an image.
 391 FILE-OR-DATA is an image file name or image data.
 392 Optional TYPE is a symbol describing the image type.  If TYPE is omitted
 393 or nil, try to determine the image type from its first few bytes
 394 of image data.  If that doesn't work, and FILE-OR-DATA is a file name,
 395 use its file extension as image type.
 396 Optional DATA-P non-nil means FILE-OR-DATA is a string containing image data.
 397 Optional PROPS are additional image attributes to assign to the image,
 398 like, e.g. `:mask MASK'.
 399 Value is the image created, or nil if images of type TYPE are not supported.
 400
 401 Images should not be larger than specified by `max-image-size'.
 402
 403 Image file names that are not absolute are searched for in the
 404 \"images\" sub-directory of `data-directory' and
 405 `x-bitmap-file-path' (in that order)."
 406   ;; It is x_find_image_file in image.c that sets the search path.
 407   (setq type (image-type file-or-data type data-p))
 408   (when (image-type-available-p type)
 409     (append (list 'image :type type (if data-p :data :file) file-or-data)
 410             props)))
 411
 412
 413 ;;;###autoload
 414 (defun put-image (image pos &optional string area)
 415   "Put image IMAGE in front of POS in the current buffer.
 416 IMAGE must be an image created with `create-image' or `defimage'.
 417 IMAGE is displayed by putting an overlay into the current buffer with a
 418 `before-string' STRING that has a `display' property whose value is the
 419 image.  STRING is defaulted if you omit it.
 420 The overlay created will have the `put-image' property set to t.
 421 POS may be an integer or marker.
 422 AREA is where to display the image.  AREA nil or omitted means
 423 display it in the text area, a value of `left-margin' means
 424 display it in the left marginal area, a value of `right-margin'
 425 means display it in the right marginal area."
 426   (unless string (setq string "x"))
 427   (let ((buffer (current-buffer)))
 428     (unless (eq (car-safe image) 'image)
 429       (error "Not an image: %s" image))
 430     (unless (or (null area) (memq area '(left-margin right-margin)))
 431       (error "Invalid area %s" area))
 432     (setq string (copy-sequence string))
 433     (let ((overlay (make-overlay pos pos buffer))
 434           (prop (if (null area) image (list (list 'margin area) image))))
 435       (put-text-property 0 (length string) 'display prop string)
 436       (overlay-put overlay 'put-image t)
 437       (overlay-put overlay 'before-string string)
 438       overlay)))
 439
 440
 441 ;;;###autoload
 442 (defun insert-image (image &optional string area slice)
 443   "Insert IMAGE into current buffer at point.
 444 IMAGE is displayed by inserting STRING into the current buffer
 445 with a `display' property whose value is the image.  STRING
 446 defaults to a single space if you omit it.
 447 AREA is where to display the image.  AREA nil or omitted means
 448 display it in the text area, a value of `left-margin' means
 449 display it in the left marginal area, a value of `right-margin'
 450 means display it in the right marginal area.
 451 SLICE specifies slice of IMAGE to insert.  SLICE nil or omitted
 452 means insert whole image.  SLICE is a list (X Y WIDTH HEIGHT)
 453 specifying the X and Y positions and WIDTH and HEIGHT of image area
 454 to insert.  A float value 0.0 - 1.0 means relative to the width or
 455 height of the image; integer values are taken as pixel values."
 456   ;; Use a space as least likely to cause trouble when it's a hidden
 457   ;; character in the buffer.
 458   (unless string (setq string " "))
 459   (unless (eq (car-safe image) 'image)
 460     (error "Not an image: %s" image))
 461   (unless (or (null area) (memq area '(left-margin right-margin)))
 462     (error "Invalid area %s" area))
 463   (if area
 464       (setq image (list (list 'margin area) image))
 465     ;; Cons up a new spec equal but not eq to `image' so that
 466     ;; inserting it twice in a row (adjacently) displays two copies of
 467     ;; the image.  Don't try to avoid this by looking at the display
 468     ;; properties on either side so that we DTRT more often with
 469     ;; cut-and-paste.  (Yanking killed image text next to another copy
 470     ;; of it loses anyway.)
 471     (setq image (cons 'image (cdr image))))
 472   (let ((start (point)))
 473     (insert string)
 474     (add-text-properties start (point)
 475                          `(display ,(if slice
 476                                         (list (cons 'slice slice) image)
 477                                       image) rear-nonsticky (display)))))
 478
 479
 480 ;;;###autoload
 481 (defun insert-sliced-image (image &optional string area rows cols)
 482   "Insert IMAGE into current buffer at point.
 483 IMAGE is displayed by inserting STRING into the current buffer
 484 with a `display' property whose value is the image.  The default
 485 STRING is a single space.
 486 AREA is where to display the image.  AREA nil or omitted means
 487 display it in the text area, a value of `left-margin' means
 488 display it in the left marginal area, a value of `right-margin'
 489 means display it in the right marginal area.
 490 The image is automatically split into ROWS x COLS slices."
 491   (unless string (setq string " "))
 492   (unless (eq (car-safe image) 'image)
 493     (error "Not an image: %s" image))
 494   (unless (or (null area) (memq area '(left-margin right-margin)))
 495     (error "Invalid area %s" area))
 496   (if area
 497       (setq image (list (list 'margin area) image))
 498     ;; Cons up a new spec equal but not eq to `image' so that
 499     ;; inserting it twice in a row (adjacently) displays two copies of
 500     ;; the image.  Don't try to avoid this by looking at the display
 501     ;; properties on either side so that we DTRT more often with
 502     ;; cut-and-paste.  (Yanking killed image text next to another copy
 503     ;; of it loses anyway.)
 504     (setq image (cons 'image (cdr image))))
 505   (let ((x 0.0) (dx (/ 1.0001 (or cols 1)))
 506          (y 0.0) (dy (/ 1.0001 (or rows 1))))
 507     (while (< y 1.0)
 508       (while (< x 1.0)
 509         (let ((start (point)))
 510           (insert string)
 511           (add-text-properties start (point)
 512                                `(display ,(list (list 'slice x y dx dy) image)
 513                                          rear-nonsticky (display)))
 514           (setq x (+ x dx))))
 515       (setq x 0.0
 516             y (+ y dy))
 517       (insert (propertize "\n" 'line-height t)))))
 518
 519
 520
 521 ;;;###autoload
 522 (defun remove-images (start end &optional buffer)
 523   "Remove images between START and END in BUFFER.
 524 Remove only images that were put in BUFFER with calls to `put-image'.
 525 BUFFER nil or omitted means use the current buffer."
 526   (unless buffer
 527     (setq buffer (current-buffer)))
 528   (let ((overlays (overlays-in start end)))
 529     (while overlays
 530       (let ((overlay (car overlays)))
 531         (when (overlay-get overlay 'put-image)
 532           (delete-overlay overlay)))
 533       (setq overlays (cdr overlays)))))
 534
 535 (defun image-search-load-path (file &optional path)
 536   (unless path
 537     (setq path image-load-path))
 538   (let (element found filename)
 539     (while (and (not found) (consp path))
 540       (setq element (car path))
 541       (cond
 542        ((stringp element)
 543         (setq found
 544               (file-readable-p
 545                (setq filename (expand-file-name file element)))))
 546        ((and (symbolp element) (boundp element))
 547         (setq element (symbol-value element))
 548         (cond
 549          ((stringp element)
 550           (setq found
 551                 (file-readable-p
 552                  (setq filename (expand-file-name file element)))))
 553          ((consp element)
 554           (if (setq filename (image-search-load-path file element))
 555               (setq found t))))))
 556       (setq path (cdr path)))
 557     (if found filename)))
 558
 559 ;;;###autoload
 560 (defun find-image (specs)
 561   "Find an image, choosing one of a list of image specifications.
 562
 563 SPECS is a list of image specifications.
 564
 565 Each image specification in SPECS is a property list.  The contents of
 566 a specification are image type dependent.  All specifications must at
 567 least contain the properties `:type TYPE' and either `:file FILE' or
 568 `:data DATA', where TYPE is a symbol specifying the image type,
 569 e.g. `xbm', FILE is the file to load the image from, and DATA is a
 570 string containing the actual image data.  The specification whose TYPE
 571 is supported, and FILE exists, is used to construct the image
 572 specification to be returned.  Return nil if no specification is
 573 satisfied.
 574
 575 The image is looked for in `image-load-path'.
 576
 577 Image files should not be larger than specified by `max-image-size'."
 578   (let (image)
 579     (while (and specs (null image))
 580       (let* ((spec (car specs))
 581              (type (plist-get spec :type))
 582              (data (plist-get spec :data))
 583              (file (plist-get spec :file))
 584              found)
 585         (when (image-type-available-p type)
 586           (cond ((stringp file)
 587                  (if (setq found (image-search-load-path file))
 588                      (setq image
 589                            (cons 'image (plist-put (copy-sequence spec)
 590                                                    :file found)))))
 591                 ((not (null data))
 592                  (setq image (cons 'image spec)))))
 593         (setq specs (cdr specs))))
 594     image))
 595
 596
 597 ;;;###autoload
 598 (defmacro defimage (symbol specs &optional doc)
 599   "Define SYMBOL as an image, and return SYMBOL.
 600
 601 SPECS is a list of image specifications.  DOC is an optional
 602 documentation string.
 603
 604 Each image specification in SPECS is a property list.  The contents of
 605 a specification are image type dependent.  All specifications must at
 606 least contain the properties `:type TYPE' and either `:file FILE' or
 607 `:data DATA', where TYPE is a symbol specifying the image type,
 608 e.g. `xbm', FILE is the file to load the image from, and DATA is a
 609 string containing the actual image data.  The first image
 610 specification whose TYPE is supported, and FILE exists, is used to
 611 define SYMBOL.
 612
 613 Example:
 614
 615    (defimage test-image ((:type xpm :file \"~/test1.xpm\")
 616                          (:type xbm :file \"~/test1.xbm\")))"
 617   (declare (doc-string 3))
 618   `(defvar ,symbol (find-image ',specs) ,doc))
 619
 620 \f
 621 ;;; Animated image API
 622
 623 (defvar image-default-frame-delay 0.1
 624   "Default interval in seconds between frames of a multi-frame image.
 625 Only used if the image does not specify a value.")
 626
 627 (defun image-multi-frame-p (image)
 628   "Return non-nil if IMAGE contains more than one frame.
 629 The actual return value is a cons (NIMAGES . DELAY), where NIMAGES is
 630 the number of frames (or sub-images) in the image and DELAY is the delay
 631 in seconds that the image specifies between each frame.  DELAY may be nil,
 632 in which case you might want to use `image-default-frame-delay'."
 633   (when (fboundp 'image-metadata)
 634     (let* ((metadata (image-metadata image))
 635            (images (plist-get metadata 'count))
 636            (delay (plist-get metadata 'delay)))
 637       (when (and images (> images 1))
 638         (if (or (not (numberp delay)) (< delay 0))
 639             (setq delay image-default-frame-delay))
 640         (cons images delay)))))
 641
 642 (defun image-animated-p (image)
 643   "Like `image-multi-frame-p', but returns nil if no delay is specified."
 644   (let ((multi (image-multi-frame-p image)))
 645     (and (cdr multi) multi)))
 646
 647 (make-obsolete 'image-animated-p 'image-multi-frame-p "24.4")
 648
 649 ;; "Destructively"?
 650 (defun image-animate (image &optional index limit)
 651   "Start animating IMAGE.
 652 Animation occurs by destructively altering the IMAGE spec list.
 653
 654 With optional INDEX, begin animating from that animation frame.
 655 LIMIT specifies how long to animate the image.  If omitted or
 656 nil, play the animation until the end.  If t, loop forever.  If a
 657 number, play until that number of seconds has elapsed."
 658   (let ((animation (image-multi-frame-p image))
 659         timer)
 660     (when animation
 661       (if (setq timer (image-animate-timer image))
 662           (cancel-timer timer))
 663       (run-with-timer 0.2 nil 'image-animate-timeout
 664                       image (or index 0) (car animation)
 665                       0 limit))))
 666
 667 (defun image-animate-timer (image)
 668   "Return the animation timer for image IMAGE."
 669   ;; See cancel-function-timers
 670   (let ((tail timer-list) timer)
 671     (while tail
 672       (setq timer (car tail)
 673             tail (cdr tail))
 674       (if (and (eq (timer--function timer) 'image-animate-timeout)
 675                (eq (car-safe (timer--args timer)) image))
 676           (setq tail nil)
 677         (setq timer nil)))
 678     timer))
 679
 680 (defconst image-minimum-frame-delay 0.01
 681   "Minimum interval in seconds between frames of an animated image.")
 682
 683 (defun image-current-frame (image)
 684   "The current frame number of IMAGE, indexed from 0."
 685   (or (plist-get (cdr image) :index) 0))
 686
 687 (defun image-show-frame (image n &optional nocheck)
 688   "Show frame N of IMAGE.
 689 Frames are indexed from 0.  Optional argument NOCHECK non-nil means
 690 do not check N is within the range of frames present in the image."
 691   (unless nocheck
 692     (if (< n 0) (setq n 0)
 693       (setq n (min n (1- (car (image-multi-frame-p image)))))))
 694   (plist-put (cdr image) :index n)
 695   (force-window-update))
 696
 697 (defun image-animate-get-speed (image)
 698   "Return the speed factor for animating IMAGE."
 699   (or (plist-get (cdr image) :speed) 1))
 700
 701 (defun image-animate-set-speed (image value &optional multiply)
 702   "Set the speed factor for animating IMAGE to VALUE.
 703 With optional argument MULTIPLY non-nil, treat VALUE as a
 704 multiplication factor for the current value."
 705   (plist-put (cdr image) :speed
 706              (if multiply
 707                  (* value (image-animate-get-speed image))
 708                value)))
 709
 710 ;; FIXME? The delay may not be the same for different sub-images,
 711 ;; hence we need to call image-multi-frame-p to return it.
 712 ;; But it also returns count, so why do we bother passing that as an
 713 ;; argument?
 714 (defun image-animate-timeout (image n count time-elapsed limit)
 715   "Display animation frame N of IMAGE.
 716 N=0 refers to the initial animation frame.
 717 COUNT is the total number of frames in the animation.
 718 TIME-ELAPSED is the total time that has elapsed since
 719 `image-animate-start' was called.
 720 LIMIT determines when to stop.  If t, loop forever.  If nil, stop
 721  after displaying the last animation frame.  Otherwise, stop
 722  after LIMIT seconds have elapsed.
 723 The minimum delay between successive frames is `image-minimum-frame-delay'.
 724
 725 If the image has a non-nil :speed property, it acts as a multiplier
 726 for the animation speed.  A negative value means to animate in reverse."
 727   (image-show-frame image n t)
 728   (let* ((speed (image-animate-get-speed image))
 729          (time (float-time))
 730          (animation (image-multi-frame-p image))
 731          ;; Subtract off the time we took to load the image from the
 732          ;; stated delay time.
 733          (delay (max (+ (* (or (cdr animation) image-default-frame-delay)
 734                            (/ 1 (abs speed)))
 735                         time (- (float-time)))
 736                      image-minimum-frame-delay))
 737          done)
 738     (setq n (if (< speed 0)
 739                 (1- n)
 740               (1+ n)))
 741     (if limit
 742         (cond ((>= n count) (setq n 0))
 743               ((< n 0) (setq n (1- count))))
 744       (and (or (>= n count) (< n 0)) (setq done t)))
 745     (setq time-elapsed (+ delay time-elapsed))
 746     (if (numberp limit)
 747         (setq done (>= time-elapsed limit)))
 748     (unless done
 749       (run-with-timer delay nil 'image-animate-timeout
 750                       image n count time-elapsed limit))))
 751
 752 \f
 753 (defvar imagemagick-types-inhibit)
 754 (defvar imagemagick-enabled-types)
 755
 756 (defun imagemagick-filter-types ()
 757   "Return a list of the ImageMagick types to be treated as images, or nil.
 758 This is the result of `imagemagick-types', including only elements
 759 that match `imagemagick-enabled-types' and do not match
 760 `imagemagick-types-inhibit'."
 761   (when (fboundp 'imagemagick-types)
 762     (cond ((null imagemagick-enabled-types) nil)
 763           ((eq imagemagick-types-inhibit t) nil)
 764           (t
 765            (delq nil
 766                  (mapcar
 767                   (lambda (type)
 768                     (unless (memq type imagemagick-types-inhibit)
 769                       (if (eq imagemagick-enabled-types t) type
 770                         (catch 'found
 771                           (dolist (enable imagemagick-enabled-types nil)
 772                             (if (cond ((symbolp enable) (eq enable type))
 773                                       ((stringp enable)
 774                                        (string-match enable
 775                                                      (symbol-name type))))
 776                                 (throw 'found type)))))))
 777                   (imagemagick-types)))))))
 778
 779 (defvar imagemagick--file-regexp nil
 780   "File extension regexp for ImageMagick files, if any.
 781 This is the extension installed into `auto-mode-alist' and
 782 `image-type-file-name-regexps' by `imagemagick-register-types'.")
 783
 784 ;;;###autoload
 785 (defun imagemagick-register-types ()
 786   "Register file types that can be handled by ImageMagick.
 787 This function is called at startup, after loading the init file.
 788 It registers the ImageMagick types returned by `imagemagick-filter-types'.
 789
 790 Registered image types are added to `auto-mode-alist', so that
 791 Emacs visits them in Image mode.  They are also added to
 792 `image-type-file-name-regexps', so that the `image-type' function
 793 recognizes these files as having image type `imagemagick'.
 794
 795 If Emacs is compiled without ImageMagick support, this does nothing."
 796   (when (fboundp 'imagemagick-types)
 797     (let* ((types (mapcar (lambda (type) (downcase (symbol-name type)))
 798                           (imagemagick-filter-types)))
 799            (re (if types (concat "\\." (regexp-opt types) "\\'")))
 800            (ama-elt (car (member (cons imagemagick--file-regexp 'image-mode)
 801                                  auto-mode-alist)))
 802            (itfnr-elt (car (member (cons imagemagick--file-regexp 'imagemagick)
 803                                    image-type-file-name-regexps))))
 804       (if (not re)
 805           (setq auto-mode-alist (delete ama-elt auto-mode-alist)
 806                 image-type-file-name-regexps
 807                 (delete itfnr-elt image-type-file-name-regexps))
 808         (if ama-elt
 809             (setcar ama-elt re)
 810           (push (cons re 'image-mode) auto-mode-alist))
 811         (if itfnr-elt
 812             (setcar itfnr-elt re)
 813           ;; Append to `image-type-file-name-regexps', so that we
 814           ;; preferentially use specialized image libraries.
 815           (add-to-list 'image-type-file-name-regexps
 816                        (cons re 'imagemagick) t)))
 817       (setq imagemagick--file-regexp re))))
 818
 819 (defcustom imagemagick-types-inhibit
 820   '(C HTML HTM INFO M TXT PDF)
 821   "List of ImageMagick types that should never be treated as images.
 822 This should be a list of symbols, each of which should be one of
 823 the ImageMagick types listed by `imagemagick-types'.  The listed
 824 image types are not registered by `imagemagick-register-types'.
 825
 826 If the value is t, inhibit the use of ImageMagick for images.
 827
 828 If you change this without using customize, you must call
 829 `imagemagick-register-types' afterwards.
 830
 831 If Emacs is compiled without ImageMagick support, this variable
 832 has no effect."
 833   :type '(choice (const :tag "Support all ImageMagick types" nil)
 834                  (const :tag "Disable all ImageMagick types" t)
 835                  (repeat symbol))
 836   :initialize 'custom-initialize-default
 837   :set (lambda (symbol value)
 838          (set-default symbol value)
 839          (imagemagick-register-types))
 840   :version "24.3"
 841   :group 'image)
 842
 843 (defcustom imagemagick-enabled-types
 844   '(3FR ART ARW AVS BMP BMP2 BMP3 CAL CALS CMYK CMYKA CR2 CRW
 845     CUR CUT DCM DCR DCX DDS DJVU DNG DPX EXR FAX FITS GBR GIF
 846     GIF87 GRB HRZ ICB ICO ICON J2C JNG JP2 JPC JPEG JPG JPX K25
 847     KDC MIFF MNG MRW MSL MSVG MTV NEF ORF OTB PBM PCD PCDS PCL
 848     PCT PCX PDB PEF PGM PICT PIX PJPEG PNG PNG24 PNG32 PNG8 PNM
 849     PPM PSD PTIF PWP RAF RAS RBG RGB RGBA RGBO RLA RLE SCR SCT
 850     SFW SGI SR2 SRF SUN SVG SVGZ TGA TIFF TIFF64 TILE TIM TTF
 851     UYVY VDA VICAR VID VIFF VST WBMP WPG X3F XBM XC XCF XPM XV
 852     XWD YCbCr YCbCrA YUV)
 853   "List of ImageMagick types to treat as images.
 854 Each list element should be a string or symbol, representing one
 855 of the image types returned by `imagemagick-types'.  If the
 856 element is a string, it is handled as a regexp that enables all
 857 matching types.
 858
 859 The value of `imagemagick-enabled-types' may also be t, meaning
 860 to enable all types that ImageMagick supports.
 861
 862 The variable `imagemagick-types-inhibit' overrides this variable.
 863
 864 If you change this without using customize, you must call
 865 `imagemagick-register-types' afterwards.
 866
 867 If Emacs is compiled without ImageMagick support, this variable
 868 has no effect."
 869   :type '(choice (const :tag "Support all ImageMagick types" t)
 870                  (const :tag "Disable all ImageMagick types" nil)
 871                  (repeat :tag "List of types"
 872                          (choice (symbol :tag "type")
 873                                  (regexp :tag "regexp"))))
 874   :initialize 'custom-initialize-default
 875   :set (lambda (symbol value)
 876          (set-default symbol value)
 877          (imagemagick-register-types))
 878   :version "24.3"
 879   :group 'image)
 880
 881 (imagemagick-register-types)
 882
 883 (provide 'image)
 884
 885 ;;; image.el ends here