lisp/image.el

   1 ;;; image.el --- image API
   2
   3 ;; Copyright (C) 1998-2016 Free Software Foundation, Inc.
   4
   5 ;; Maintainer: emacs-devel@gnu.org
   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   "An alist associating image types with file name suffixes.
 108 This is used as a hint by the ImageMagick library when detecting
 109 the type of image data (that does not have an associated file name).
 110 Each element has the form (MIME-CONTENT-TYPE EXTENSION).
 111 If `create-image' is called with a :format attribute whose value
 112 equals a content-type found in this list, the ImageMagick library is
 113 told that the data would have the associated suffix if saved to a file.")
 114
 115 (defcustom image-load-path
 116   (list (file-name-as-directory (expand-file-name "images" data-directory))
 117         'data-directory 'load-path)
 118   "List of locations in which to search for image files.
 119 If an element is a string, it defines a directory to search.
 120 If an element is a variable symbol whose value is a string, that
 121 value defines a directory to search.
 122 If an element is a variable symbol whose value is a list, the
 123 value is used as a list of directories to search.
 124
 125 Subdirectories are not automatically included in the search."
 126   :type '(repeat (choice directory variable))
 127   :initialize 'custom-initialize-delay)
 128
 129
 130 (defun image-load-path-for-library (library image &optional path no-error)
 131   "Return a suitable search path for images used by LIBRARY.
 132
 133 It searches for IMAGE in `image-load-path' (excluding
 134 \"`data-directory'/images\") and `load-path', followed by a path
 135 suitable for LIBRARY, which includes \"../../etc/images\" and
 136 \"../etc/images\" relative to the library file itself, and then
 137 in \"`data-directory'/images\".
 138
 139 Then this function returns a list of directories which contains
 140 first the directory in which IMAGE was found, followed by the
 141 value of `load-path'.  If PATH is given, it is used instead of
 142 `load-path'.
 143
 144 If NO-ERROR is non-nil and a suitable path can't be found, don't
 145 signal an error.  Instead, return a list of directories as before,
 146 except that nil appears in place of the image directory.
 147
 148 Here is an example that uses a common idiom to provide
 149 compatibility with versions of Emacs that lack the variable
 150 `image-load-path':
 151
 152     ;; Shush compiler.
 153     (defvar image-load-path)
 154
 155     (let* ((load-path (image-load-path-for-library \"mh-e\" \"mh-logo.xpm\"))
 156            (image-load-path (cons (car load-path)
 157                                   (when (boundp \\='image-load-path)
 158                                     image-load-path))))
 159       (mh-tool-bar-folder-buttons-init))"
 160   (unless library (error "No library specified"))
 161   (unless image   (error "No image specified"))
 162   (let (image-directory image-directory-load-path)
 163     ;; Check for images in image-load-path or load-path.
 164     (let ((img image)
 165           (dir (or
 166                 ;; Images in image-load-path.
 167                 (image-search-load-path image)
 168                 ;; Images in load-path.
 169                 (locate-library image)))
 170           parent)
 171       ;; Since the image might be in a nested directory (for
 172       ;; example, mail/attach.pbm), adjust `image-directory'
 173       ;; accordingly.
 174       (when dir
 175         (setq dir (file-name-directory dir))
 176         (while (setq parent (file-name-directory img))
 177           (setq img (directory-file-name parent)
 178                 dir (expand-file-name "../" dir))))
 179       (setq image-directory-load-path dir))
 180
 181     ;; If `image-directory-load-path' isn't Emacs's image directory,
 182     ;; it's probably a user preference, so use it. Then use a
 183     ;; relative setting if possible; otherwise, use
 184     ;; `image-directory-load-path'.
 185     (cond
 186      ;; User-modified image-load-path?
 187      ((and image-directory-load-path
 188            (not (equal image-directory-load-path
 189                        (file-name-as-directory
 190                         (expand-file-name "images" data-directory)))))
 191       (setq image-directory image-directory-load-path))
 192      ;; Try relative setting.
 193      ((let (library-name d1ei d2ei)
 194         ;; First, find library in the load-path.
 195         (setq library-name (locate-library library))
 196         (if (not library-name)
 197             (error "Cannot find library %s in load-path" library))
 198         ;; And then set image-directory relative to that.
 199         (setq
 200          ;; Go down 2 levels.
 201          d2ei (file-name-as-directory
 202                (expand-file-name
 203                 (concat (file-name-directory library-name) "../../etc/images")))
 204          ;; Go down 1 level.
 205          d1ei (file-name-as-directory
 206                (expand-file-name
 207                 (concat (file-name-directory library-name) "../etc/images"))))
 208         (setq image-directory
 209               ;; Set it to nil if image is not found.
 210               (cond ((file-exists-p (expand-file-name image d2ei)) d2ei)
 211                     ((file-exists-p (expand-file-name image d1ei)) d1ei)))))
 212      ;; Use Emacs's image directory.
 213      (image-directory-load-path
 214       (setq image-directory image-directory-load-path))
 215      (no-error
 216       (message "Could not find image %s for library %s" image library))
 217      (t
 218       (error "Could not find image %s for library %s" image library)))
 219
 220     ;; Return an augmented `path' or `load-path'.
 221     (nconc (list image-directory)
 222            (delete image-directory (copy-sequence (or path load-path))))))
 223
 224
 225 ;; Used to be in image-type-header-regexps, but now not used anywhere
 226 ;; (since 2009-08-28).
 227 (defun image-jpeg-p (data)
 228   "Value is non-nil if DATA, a string, consists of JFIF image data.
 229 We accept the tag Exif because that is the same format."
 230   (setq data (ignore-errors (string-to-unibyte data)))
 231   (when (and data (string-match-p "\\`\xff\xd8" data))
 232     (catch 'jfif
 233       (let ((len (length data)) (i 2))
 234         (while (< i len)
 235           (when (/= (aref data i) #xff)
 236             (throw 'jfif nil))
 237           (setq i (1+ i))
 238           (when (>= (+ i 2) len)
 239             (throw 'jfif nil))
 240           (let ((nbytes (+ (lsh (aref data (+ i 1)) 8)
 241                            (aref data (+ i 2))))
 242                 (code (aref data i)))
 243             (when (and (>= code #xe0) (<= code #xef))
 244               ;; APP0 LEN1 LEN2 "JFIF\0"
 245               (throw 'jfif
 246                      (string-match-p "JFIF\\|Exif"
 247                                      (substring data i (min (+ i nbytes) len)))))
 248             (setq i (+ i 1 nbytes))))))))
 249
 250
 251 ;;;###autoload
 252 (defun image-type-from-data (data)
 253   "Determine the image type from image data DATA.
 254 Value is a symbol specifying the image type or nil if type cannot
 255 be determined."
 256   (let ((types image-type-header-regexps)
 257         type)
 258     (while types
 259       (let ((regexp (car (car types)))
 260             (image-type (cdr (car types))))
 261         (if (or (and (symbolp image-type)
 262                      (string-match-p regexp data))
 263                 (and (consp image-type)
 264                      (funcall (car image-type) data)
 265                      (setq image-type (cdr image-type))))
 266             (setq type image-type
 267                   types nil)
 268           (setq types (cdr types)))))
 269     type))
 270
 271
 272 ;;;###autoload
 273 (defun image-type-from-buffer ()
 274   "Determine the image type from data in the current buffer.
 275 Value is a symbol specifying the image type or nil if type cannot
 276 be determined."
 277   (let ((types image-type-header-regexps)
 278         type
 279         (opoint (point)))
 280     (goto-char (point-min))
 281     (while types
 282       (let ((regexp (car (car types)))
 283             (image-type (cdr (car types)))
 284             data)
 285         (if (or (and (symbolp image-type)
 286                      (looking-at-p regexp))
 287                 (and (consp image-type)
 288                      (funcall (car image-type)
 289                               (or data
 290                                   (setq data
 291                                         (buffer-substring
 292                                          (point-min)
 293                                          (min (point-max)
 294                                               (+ (point-min) 256))))))
 295                      (setq image-type (cdr image-type))))
 296             (setq type image-type
 297                   types nil)
 298           (setq types (cdr types)))))
 299     (goto-char opoint)
 300     (and type
 301          (boundp 'image-types)
 302          (memq type image-types)
 303          type)))
 304
 305
 306 ;;;###autoload
 307 (defun image-type-from-file-header (file)
 308   "Determine the type of image file FILE from its first few bytes.
 309 Value is a symbol specifying the image type, or nil if type cannot
 310 be determined."
 311   (unless (or (file-readable-p file)
 312               (file-name-absolute-p file))
 313     (setq file (image-search-load-path file)))
 314   (and file
 315        (file-readable-p file)
 316        (with-temp-buffer
 317          (set-buffer-multibyte nil)
 318          (insert-file-contents-literally file nil 0 256)
 319          (image-type-from-buffer))))
 320
 321
 322 ;;;###autoload
 323 (defun image-type-from-file-name (file)
 324   "Determine the type of image file FILE from its name.
 325 Value is a symbol specifying the image type, or nil if type cannot
 326 be determined."
 327   (let (type first)
 328     (catch 'found
 329       (dolist (elem image-type-file-name-regexps first)
 330         (when (string-match-p (car elem) file)
 331           (if (image-type-available-p (setq type (cdr elem)))
 332               (throw 'found type)
 333             ;; If nothing seems to be supported, return first type that matched.
 334             (or first (setq first type))))))))
 335
 336 ;;;###autoload
 337 (defun image-type (source &optional type data-p)
 338   "Determine and return image type.
 339 SOURCE is an image file name or image data.
 340 Optional TYPE is a symbol describing the image type.  If TYPE is omitted
 341 or nil, try to determine the image type from its first few bytes
 342 of image data.  If that doesn't work, and SOURCE is a file name,
 343 use its file extension as image type.
 344 Optional DATA-P non-nil means SOURCE is a string containing image data."
 345   (when (and (not data-p) (not (stringp source)))
 346     (error "Invalid image file name `%s'" source))
 347   (unless type
 348     (setq type (if data-p
 349                    (image-type-from-data source)
 350                  (or (image-type-from-file-header source)
 351                      (image-type-from-file-name source))))
 352     (or type (error "Cannot determine image type")))
 353   (or (memq type (and (boundp 'image-types) image-types))
 354       (error "Invalid image type `%s'" type))
 355   type)
 356
 357
 358 (if (fboundp 'image-metadata)           ; eg not --without-x
 359     (define-obsolete-function-alias 'image-extension-data
 360       'image-metadata "24.1"))
 361
 362 (define-obsolete-variable-alias
 363     'image-library-alist
 364     'dynamic-library-alist "24.1")
 365
 366 ;;;###autoload
 367 (defun image-type-available-p (type)
 368   "Return non-nil if image type TYPE is available.
 369 Image types are symbols like `xbm' or `jpeg'."
 370   (and (fboundp 'init-image-library)
 371        (init-image-library type)))
 372
 373
 374 ;;;###autoload
 375 (defun image-type-auto-detected-p ()
 376   "Return t if the current buffer contains an auto-detectable image.
 377 This function is intended to be used from `magic-fallback-mode-alist'.
 378
 379 The buffer is considered to contain an auto-detectable image if
 380 its beginning matches an image type in `image-type-header-regexps',
 381 and that image type is present in `image-type-auto-detectable' with a
 382 non-nil value.  If that value is non-nil, but not t, then the image type
 383 must be available."
 384   (let* ((type (image-type-from-buffer))
 385          (auto (and type (cdr (assq type image-type-auto-detectable)))))
 386     (and auto
 387          (or (eq auto t) (image-type-available-p type)))))
 388
 389
 390 ;;;###autoload
 391 (defun create-image (file-or-data &optional type data-p &rest props)
 392   "Create an image.
 393 FILE-OR-DATA is an image file name or image data.
 394 Optional TYPE is a symbol describing the image type.  If TYPE is omitted
 395 or nil, try to determine the image type from its first few bytes
 396 of image data.  If that doesn't work, and FILE-OR-DATA is a file name,
 397 use its file extension as image type.
 398 Optional DATA-P non-nil means FILE-OR-DATA is a string containing image data.
 399 Optional PROPS are additional image attributes to assign to the image,
 400 like, e.g. `:mask MASK'.
 401 Value is the image created, or nil if images of type TYPE are not supported.
 402
 403 Images should not be larger than specified by `max-image-size'.
 404
 405 Image file names that are not absolute are searched for in the
 406 \"images\" sub-directory of `data-directory' and
 407 `x-bitmap-file-path' (in that order)."
 408   ;; It is x_find_image_file in image.c that sets the search path.
 409   (setq type (image-type file-or-data type data-p))
 410   (when (image-type-available-p type)
 411     (append (list 'image :type type (if data-p :data :file) file-or-data)
 412             props)))
 413
 414
 415 ;;;###autoload
 416 (defun put-image (image pos &optional string area)
 417   "Put image IMAGE in front of POS in the current buffer.
 418 IMAGE must be an image created with `create-image' or `defimage'.
 419 IMAGE is displayed by putting an overlay into the current buffer with a
 420 `before-string' STRING that has a `display' property whose value is the
 421 image.  STRING is defaulted if you omit it.
 422 The overlay created will have the `put-image' property set to t.
 423 POS may be an integer or marker.
 424 AREA is where to display the image.  AREA nil or omitted means
 425 display it in the text area, a value of `left-margin' means
 426 display it in the left marginal area, a value of `right-margin'
 427 means display it in the right marginal area."
 428   (unless string (setq string "x"))
 429   (let ((buffer (current-buffer)))
 430     (unless (eq (car-safe image) 'image)
 431       (error "Not an image: %s" image))
 432     (unless (or (null area) (memq area '(left-margin right-margin)))
 433       (error "Invalid area %s" area))
 434     (setq string (copy-sequence string))
 435     (let ((overlay (make-overlay pos pos buffer))
 436           (prop (if (null area) image (list (list 'margin area) image))))
 437       (put-text-property 0 (length string) 'display prop string)
 438       (overlay-put overlay 'put-image t)
 439       (overlay-put overlay 'before-string string)
 440       overlay)))
 441
 442
 443 ;;;###autoload
 444 (defun insert-image (image &optional string area slice)
 445   "Insert IMAGE into current buffer at point.
 446 IMAGE is displayed by inserting STRING into the current buffer
 447 with a `display' property whose value is the image.  STRING
 448 defaults to a single space if you omit it.
 449 AREA is where to display the image.  AREA nil or omitted means
 450 display it in the text area, a value of `left-margin' means
 451 display it in the left marginal area, a value of `right-margin'
 452 means display it in the right marginal area.
 453 SLICE specifies slice of IMAGE to insert.  SLICE nil or omitted
 454 means insert whole image.  SLICE is a list (X Y WIDTH HEIGHT)
 455 specifying the X and Y positions and WIDTH and HEIGHT of image area
 456 to insert.  A float value 0.0 - 1.0 means relative to the width or
 457 height of the image; integer values are taken as pixel values."
 458   ;; Use a space as least likely to cause trouble when it's a hidden
 459   ;; character in the buffer.
 460   (unless string (setq string " "))
 461   (unless (eq (car-safe image) 'image)
 462     (error "Not an image: %s" image))
 463   (unless (or (null area) (memq area '(left-margin right-margin)))
 464     (error "Invalid area %s" area))
 465   (if area
 466       (setq image (list (list 'margin area) image))
 467     ;; Cons up a new spec equal but not eq to `image' so that
 468     ;; inserting it twice in a row (adjacently) displays two copies of
 469     ;; the image.  Don't try to avoid this by looking at the display
 470     ;; properties on either side so that we DTRT more often with
 471     ;; cut-and-paste.  (Yanking killed image text next to another copy
 472     ;; of it loses anyway.)
 473     (setq image (cons 'image (cdr image))))
 474   (let ((start (point)))
 475     (insert string)
 476     (add-text-properties start (point)
 477                          `(display ,(if slice
 478                                         (list (cons 'slice slice) image)
 479                                       image) rear-nonsticky (display)))))
 480
 481
 482 ;;;###autoload
 483 (defun insert-sliced-image (image &optional string area rows cols)
 484   "Insert IMAGE into current buffer at point.
 485 IMAGE is displayed by inserting STRING into the current buffer
 486 with a `display' property whose value is the image.  The default
 487 STRING is a single space.
 488 AREA is where to display the image.  AREA nil or omitted means
 489 display it in the text area, a value of `left-margin' means
 490 display it in the left marginal area, a value of `right-margin'
 491 means display it in the right marginal area.
 492 The image is automatically split into ROWS x COLS slices."
 493   (unless string (setq string " "))
 494   (unless (eq (car-safe image) 'image)
 495     (error "Not an image: %s" image))
 496   (unless (or (null area) (memq area '(left-margin right-margin)))
 497     (error "Invalid area %s" area))
 498   (if area
 499       (setq image (list (list 'margin area) image))
 500     ;; Cons up a new spec equal but not eq to `image' so that
 501     ;; inserting it twice in a row (adjacently) displays two copies of
 502     ;; the image.  Don't try to avoid this by looking at the display
 503     ;; properties on either side so that we DTRT more often with
 504     ;; cut-and-paste.  (Yanking killed image text next to another copy
 505     ;; of it loses anyway.)
 506     (setq image (cons 'image (cdr image))))
 507   (let ((x 0.0) (dx (/ 1.0001 (or cols 1)))
 508          (y 0.0) (dy (/ 1.0001 (or rows 1))))
 509     (while (< y 1.0)
 510       (while (< x 1.0)
 511         (let ((start (point)))
 512           (insert string)
 513           (add-text-properties start (point)
 514                                `(display ,(list (list 'slice x y dx dy) image)
 515                                          rear-nonsticky (display)))
 516           (setq x (+ x dx))))
 517       (setq x 0.0
 518             y (+ y dy))
 519       (insert (propertize "\n" 'line-height t)))))
 520
 521
 522
 523 ;;;###autoload
 524 (defun remove-images (start end &optional buffer)
 525   "Remove images between START and END in BUFFER.
 526 Remove only images that were put in BUFFER with calls to `put-image'.
 527 BUFFER nil or omitted means use the current buffer."
 528   (unless buffer
 529     (setq buffer (current-buffer)))
 530   (let ((overlays (overlays-in start end)))
 531     (while overlays
 532       (let ((overlay (car overlays)))
 533         (when (overlay-get overlay 'put-image)
 534           (delete-overlay overlay)))
 535       (setq overlays (cdr overlays)))))
 536
 537 (defun image-search-load-path (file &optional path)
 538   (unless path
 539     (setq path image-load-path))
 540   (let (element found filename)
 541     (while (and (not found) (consp path))
 542       (setq element (car path))
 543       (cond
 544        ((stringp element)
 545         (setq found
 546               (file-readable-p
 547                (setq filename (expand-file-name file element)))))
 548        ((and (symbolp element) (boundp element))
 549         (setq element (symbol-value element))
 550         (cond
 551          ((stringp element)
 552           (setq found
 553                 (file-readable-p
 554                  (setq filename (expand-file-name file element)))))
 555          ((consp element)
 556           (if (setq filename (image-search-load-path file element))
 557               (setq found t))))))
 558       (setq path (cdr path)))
 559     (if found filename)))
 560
 561 ;;;###autoload
 562 (defun find-image (specs)
 563   "Find an image, choosing one of a list of image specifications.
 564
 565 SPECS is a list of image specifications.
 566
 567 Each image specification in SPECS is a property list.  The contents of
 568 a specification are image type dependent.  All specifications must at
 569 least contain the properties `:type TYPE' and either `:file FILE' or
 570 `:data DATA', where TYPE is a symbol specifying the image type,
 571 e.g. `xbm', FILE is the file to load the image from, and DATA is a
 572 string containing the actual image data.  The specification whose TYPE
 573 is supported, and FILE exists, is used to construct the image
 574 specification to be returned.  Return nil if no specification is
 575 satisfied.
 576
 577 The image is looked for in `image-load-path'.
 578
 579 Image files should not be larger than specified by `max-image-size'."
 580   (let (image)
 581     (while (and specs (null image))
 582       (let* ((spec (car specs))
 583              (type (plist-get spec :type))
 584              (data (plist-get spec :data))
 585              (file (plist-get spec :file))
 586              found)
 587         (when (image-type-available-p type)
 588           (cond ((stringp file)
 589                  (if (setq found (image-search-load-path file))
 590                      (setq image
 591                            (cons 'image (plist-put (copy-sequence spec)
 592                                                    :file found)))))
 593                 ((not (null data))
 594                  (setq image (cons 'image spec)))))
 595         (setq specs (cdr specs))))
 596     image))
 597
 598
 599 ;;;###autoload
 600 (defmacro defimage (symbol specs &optional doc)
 601   "Define SYMBOL as an image, and return SYMBOL.
 602
 603 SPECS is a list of image specifications.  DOC is an optional
 604 documentation string.
 605
 606 Each image specification in SPECS is a property list.  The contents of
 607 a specification are image type dependent.  All specifications must at
 608 least contain the properties `:type TYPE' and either `:file FILE' or
 609 `:data DATA', where TYPE is a symbol specifying the image type,
 610 e.g. `xbm', FILE is the file to load the image from, and DATA is a
 611 string containing the actual image data.  The first image
 612 specification whose TYPE is supported, and FILE exists, is used to
 613 define SYMBOL.
 614
 615 Example:
 616
 617    (defimage test-image ((:type xpm :file \"~/test1.xpm\")
 618                          (:type xbm :file \"~/test1.xbm\")))"
 619   (declare (doc-string 3))
 620   `(defvar ,symbol (find-image ',specs) ,doc))
 621
 622 \f
 623 ;;; Animated image API
 624
 625 (defvar image-default-frame-delay 0.1
 626   "Default interval in seconds between frames of a multi-frame image.
 627 Only used if the image does not specify a value.")
 628
 629 (defun image-multi-frame-p (image)
 630   "Return non-nil if IMAGE contains more than one frame.
 631 The actual return value is a cons (NIMAGES . DELAY), where NIMAGES is
 632 the number of frames (or sub-images) in the image and DELAY is the delay
 633 in seconds that the image specifies between each frame.  DELAY may be nil,
 634 in which case you might want to use `image-default-frame-delay'."
 635   (when (fboundp 'image-metadata)
 636     (let* ((metadata (image-metadata image))
 637            (images (plist-get metadata 'count))
 638            (delay (plist-get metadata 'delay)))
 639       (when (and images (> images 1))
 640         (and delay (or (not (numberp delay)) (< delay 0))
 641              (setq delay image-default-frame-delay))
 642         (cons images delay)))))
 643
 644 (defun image-animated-p (image)
 645   "Like `image-multi-frame-p', but returns nil if no delay is specified."
 646   (let ((multi (image-multi-frame-p image)))
 647     (and (cdr multi) multi)))
 648
 649 (make-obsolete 'image-animated-p 'image-multi-frame-p "24.4")
 650
 651 ;; "Destructively"?
 652 (defun image-animate (image &optional index limit)
 653   "Start animating IMAGE.
 654 Animation occurs by destructively altering the IMAGE spec list.
 655
 656 With optional INDEX, begin animating from that animation frame.
 657 LIMIT specifies how long to animate the image.  If omitted or
 658 nil, play the animation until the end.  If t, loop forever.  If a
 659 number, play until that number of seconds has elapsed."
 660   (let ((animation (image-multi-frame-p image))
 661         timer)
 662     (when animation
 663       (if (setq timer (image-animate-timer image))
 664           (cancel-timer timer))
 665       (plist-put (cdr image) :animate-buffer (current-buffer))
 666       (run-with-timer 0.2 nil 'image-animate-timeout
 667                       image (or index 0) (car animation)
 668                       0 limit))))
 669
 670 (defun image-animate-timer (image)
 671   "Return the animation timer for image IMAGE."
 672   ;; See cancel-function-timers
 673   (let ((tail timer-list) timer)
 674     (while tail
 675       (setq timer (car tail)
 676             tail (cdr tail))
 677       (if (and (eq (timer--function timer) 'image-animate-timeout)
 678                (eq (car-safe (timer--args timer)) image))
 679           (setq tail nil)
 680         (setq timer nil)))
 681     timer))
 682
 683 (defconst image-minimum-frame-delay 0.01
 684   "Minimum interval in seconds between frames of an animated image.")
 685
 686 (defun image-current-frame (image)
 687   "The current frame number of IMAGE, indexed from 0."
 688   (or (plist-get (cdr image) :index) 0))
 689
 690 (defun image-show-frame (image n &optional nocheck)
 691   "Show frame N of IMAGE.
 692 Frames are indexed from 0.  Optional argument NOCHECK non-nil means
 693 do not check N is within the range of frames present in the image."
 694   (unless nocheck
 695     (if (< n 0) (setq n 0)
 696       (setq n (min n (1- (car (image-multi-frame-p image)))))))
 697   (plist-put (cdr image) :index n)
 698   (force-window-update))
 699
 700 (defun image-animate-get-speed (image)
 701   "Return the speed factor for animating IMAGE."
 702   (or (plist-get (cdr image) :speed) 1))
 703
 704 (defun image-animate-set-speed (image value &optional multiply)
 705   "Set the speed factor for animating IMAGE to VALUE.
 706 With optional argument MULTIPLY non-nil, treat VALUE as a
 707 multiplication factor for the current value."
 708   (plist-put (cdr image) :speed
 709              (if multiply
 710                  (* value (image-animate-get-speed image))
 711                value)))
 712
 713 ;; FIXME? The delay may not be the same for different sub-images,
 714 ;; hence we need to call image-multi-frame-p to return it.
 715 ;; But it also returns count, so why do we bother passing that as an
 716 ;; argument?
 717 (defun image-animate-timeout (image n count time-elapsed limit)
 718   "Display animation frame N of IMAGE.
 719 N=0 refers to the initial animation frame.
 720 COUNT is the total number of frames in the animation.
 721 TIME-ELAPSED is the total time that has elapsed since
 722 `image-animate-start' was called.
 723 LIMIT determines when to stop.  If t, loop forever.  If nil, stop
 724  after displaying the last animation frame.  Otherwise, stop
 725  after LIMIT seconds have elapsed.
 726 The minimum delay between successive frames is `image-minimum-frame-delay'.
 727
 728 If the image has a non-nil :speed property, it acts as a multiplier
 729 for the animation speed.  A negative value means to animate in reverse."
 730   (when (buffer-live-p (plist-get (cdr image) :animate-buffer))
 731     (image-show-frame image n t)
 732     (let* ((speed (image-animate-get-speed image))
 733            (time (float-time))
 734            (animation (image-multi-frame-p image))
 735            ;; Subtract off the time we took to load the image from the
 736            ;; stated delay time.
 737            (delay (max (+ (* (or (cdr animation) image-default-frame-delay)
 738                              (/ 1.0 (abs speed)))
 739                           time (- (float-time)))
 740                        image-minimum-frame-delay))
 741            done)
 742       (setq n (if (< speed 0)
 743                   (1- n)
 744                 (1+ n)))
 745       (if limit
 746           (cond ((>= n count) (setq n 0))
 747                 ((< n 0) (setq n (1- count))))
 748         (and (or (>= n count) (< n 0)) (setq done t)))
 749       (setq time-elapsed (+ delay time-elapsed))
 750       (if (numberp limit)
 751           (setq done (>= time-elapsed limit)))
 752       (unless done
 753         (run-with-timer delay nil 'image-animate-timeout
 754                         image n count time-elapsed limit)))))
 755
 756 \f
 757 (defvar imagemagick-types-inhibit)
 758 (defvar imagemagick-enabled-types)
 759
 760 (defun imagemagick-filter-types ()
 761   "Return a list of the ImageMagick types to be treated as images, or nil.
 762 This is the result of `imagemagick-types', including only elements
 763 that match `imagemagick-enabled-types' and do not match
 764 `imagemagick-types-inhibit'."
 765   (when (fboundp 'imagemagick-types)
 766     (cond ((null imagemagick-enabled-types) nil)
 767           ((eq imagemagick-types-inhibit t) nil)
 768           (t
 769            (delq nil
 770                  (mapcar
 771                   (lambda (type)
 772                     (unless (memq type imagemagick-types-inhibit)
 773                       (if (eq imagemagick-enabled-types t) type
 774                         (catch 'found
 775                           (dolist (enable imagemagick-enabled-types nil)
 776                             (if (cond ((symbolp enable) (eq enable type))
 777                                       ((stringp enable)
 778                                        (string-match enable
 779                                                      (symbol-name type))))
 780                                 (throw 'found type)))))))
 781                   (imagemagick-types)))))))
 782
 783 (defvar imagemagick--file-regexp nil
 784   "File extension regexp for ImageMagick files, if any.
 785 This is the extension installed into `auto-mode-alist' and
 786 `image-type-file-name-regexps' by `imagemagick-register-types'.")
 787
 788 ;;;###autoload
 789 (defun imagemagick-register-types ()
 790   "Register file types that can be handled by ImageMagick.
 791 This function is called at startup, after loading the init file.
 792 It registers the ImageMagick types returned by `imagemagick-filter-types'.
 793
 794 Registered image types are added to `auto-mode-alist', so that
 795 Emacs visits them in Image mode.  They are also added to
 796 `image-type-file-name-regexps', so that the `image-type' function
 797 recognizes these files as having image type `imagemagick'.
 798
 799 If Emacs is compiled without ImageMagick support, this does nothing."
 800   (when (fboundp 'imagemagick-types)
 801     (let* ((types (mapcar (lambda (type) (downcase (symbol-name type)))
 802                           (imagemagick-filter-types)))
 803            (re (if types (concat "\\." (regexp-opt types) "\\'")))
 804            (ama-elt (car (member (cons imagemagick--file-regexp 'image-mode)
 805                                  auto-mode-alist)))
 806            (itfnr-elt (car (member (cons imagemagick--file-regexp 'imagemagick)
 807                                    image-type-file-name-regexps))))
 808       (if (not re)
 809           (setq auto-mode-alist (delete ama-elt auto-mode-alist)
 810                 image-type-file-name-regexps
 811                 (delete itfnr-elt image-type-file-name-regexps))
 812         (if ama-elt
 813             (setcar ama-elt re)
 814           (push (cons re 'image-mode) auto-mode-alist))
 815         (if itfnr-elt
 816             (setcar itfnr-elt re)
 817           ;; Append to `image-type-file-name-regexps', so that we
 818           ;; preferentially use specialized image libraries.
 819           (add-to-list 'image-type-file-name-regexps
 820                        (cons re 'imagemagick) t)))
 821       (setq imagemagick--file-regexp re))))
 822
 823 (defcustom imagemagick-types-inhibit
 824   '(C HTML HTM INFO M TXT PDF)
 825   "List of ImageMagick types that should never be treated as images.
 826 This should be a list of symbols, each of which should be one of
 827 the ImageMagick types listed by `imagemagick-types'.  The listed
 828 image types are not registered by `imagemagick-register-types'.
 829
 830 If the value is t, inhibit the use of ImageMagick for images.
 831
 832 If you change this without using customize, you must call
 833 `imagemagick-register-types' afterwards.
 834
 835 If Emacs is compiled without ImageMagick support, this variable
 836 has no effect."
 837   :type '(choice (const :tag "Support all ImageMagick types" nil)
 838                  (const :tag "Disable all ImageMagick types" t)
 839                  (repeat symbol))
 840   :initialize 'custom-initialize-default
 841   :set (lambda (symbol value)
 842          (set-default symbol value)
 843          (imagemagick-register-types))
 844   :version "24.3"
 845   :group 'image)
 846
 847 (defcustom imagemagick-enabled-types
 848   '(3FR ART ARW AVS BMP BMP2 BMP3 CAL CALS CMYK CMYKA CR2 CRW
 849     CUR CUT DCM DCR DCX DDS DJVU DNG DPX EXR FAX FITS GBR GIF
 850     GIF87 GRB HRZ ICB ICO ICON J2C JNG JP2 JPC JPEG JPG JPX K25
 851     KDC MIFF MNG MRW MSL MSVG MTV NEF ORF OTB PBM PCD PCDS PCL
 852     PCT PCX PDB PEF PGM PICT PIX PJPEG PNG PNG24 PNG32 PNG8 PNM
 853     PPM PSD PTIF PWP RAF RAS RBG RGB RGBA RGBO RLA RLE SCR SCT
 854     SFW SGI SR2 SRF SUN SVG SVGZ TGA TIFF TIFF64 TILE TIM TTF
 855     UYVY VDA VICAR VID VIFF VST WBMP WPG X3F XBM XC XCF XPM XV
 856     XWD YCbCr YCbCrA YUV)
 857   "List of ImageMagick types to treat as images.
 858 Each list element should be a string or symbol, representing one
 859 of the image types returned by `imagemagick-types'.  If the
 860 element is a string, it is handled as a regexp that enables all
 861 matching types.
 862
 863 The value of `imagemagick-enabled-types' may also be t, meaning
 864 to enable all types that ImageMagick supports.
 865
 866 The variable `imagemagick-types-inhibit' overrides this variable.
 867
 868 If you change this without using customize, you must call
 869 `imagemagick-register-types' afterwards.
 870
 871 If Emacs is compiled without ImageMagick support, this variable
 872 has no effect."
 873   :type '(choice (const :tag "Support all ImageMagick types" t)
 874                  (const :tag "Disable all ImageMagick types" nil)
 875                  (repeat :tag "List of types"
 876                          (choice (symbol :tag "type")
 877                                  (regexp :tag "regexp"))))
 878   :initialize 'custom-initialize-default
 879   :set (lambda (symbol value)
 880          (set-default symbol value)
 881          (imagemagick-register-types))
 882   :version "24.3"
 883   :group 'image)
 884
 885 (imagemagick-register-types)
 886
 887 (provide 'image)
 888
 889 ;;; image.el ends here