;;; image.el --- image API
-;; Copyright (C) 1998 Free Software Foundation, Inc.
+;; Copyright (C) 1998, 99, 2000, 01, 04 Free Software Foundation, Inc.
+
+;; Maintainer: FSF
;; Keywords: multimedia
;; This file is part of GNU Emacs.
;;; Code:
+
+(defgroup image ()
+ "Image support."
+ :group 'multimedia)
+
+
(defconst image-type-regexps
- '(("^/\\*.*XPM.\\*/" . xpm)
- ("^P[1-6]" . pbm)
- ("^GIF8" . gif)
- ("JFIF" . jpeg)
- ("^\211PNG\r\n" . png)
- ("^#define" . xbm)
- ("^\\(MM\0\\*\\)\\|\\(II\\*\0\\)" . tiff)
- ("^%!PS" . ghostscript))
+ '(("\\`/[\t\n\r ]*\\*.*XPM.\\*/" . xpm)
+ ("\\`P[1-6]" . pbm)
+ ("\\`GIF8" . gif)
+ ("\\`\211PNG\r\n" . png)
+ ("\\`[\t\n\r ]*#define" . xbm)
+ ("\\`\\(MM\0\\*\\|II\\*\0\\)" . tiff)
+ ("\\`[\t\n\r ]*%!PS" . postscript)
+ ("\\`\xff\xd8" . (image-jpeg-p . jpeg)))
"Alist of (REGEXP . IMAGE-TYPE) pairs used to auto-detect image types.
When the first bytes of an image file match REGEXP, it is assumed to
-be of image type IMAGE-TYPE.")
+be of image type IMAGE-TYPE if IMAGE-TYPE is a symbol. If not a symbol,
+IMAGE-TYPE must be a pair (PREDICATE . TYPE). PREDICATE is called
+with one argument, a string containing the image data. If PREDICATE returns
+a non-nil value, TYPE is the image's type.")
+
+;;;###autoload
+(defvar image-library-alist nil
+ "Alist of image types vs external libraries needed to display them.
+
+Each element is a list (IMAGE-TYPE LIBRARY...), where the car is a symbol
+representing a supported image type, and the rest are strings giving
+alternate filenames for the corresponding external libraries.
+
+Emacs tries to load the libraries in the order they appear on the
+list; if none is loaded, the running session of Emacs won't
+support the image type. Types 'pbm and 'xbm don't need to be
+listed; they're always supported.")
+;;;###autoload (put 'image-library-alist 'risky-local-variable t)
+
+(defun image-jpeg-p (data)
+ "Value is non-nil if DATA, a string, consists of JFIF image data.
+We accept the tag Exif because that is the same format."
+ (when (string-match "\\`\xff\xd8" data)
+ (catch 'jfif
+ (let ((len (length data)) (i 2))
+ (while (< i len)
+ (when (/= (aref data i) #xff)
+ (throw 'jfif nil))
+ (setq i (1+ i))
+ (when (>= (+ i 2) len)
+ (throw 'jfif nil))
+ (let ((nbytes (+ (lsh (aref data (+ i 1)) 8)
+ (aref data (+ i 2))))
+ (code (aref data i)))
+ (when (and (>= code #xe0) (<= code #xef))
+ ;; APP0 LEN1 LEN2 "JFIF\0"
+ (throw 'jfif
+ (string-match "JFIF\\|Exif"
+ (substring data i (min (+ i nbytes) len)))))
+ (setq i (+ i 1 nbytes))))))))
;;;###autoload
-(defun image-type-from-file-header (file)
- "Determine the type of image file FILE from its first few bytes.
-Value is a symbol specifying the image type, or nil if type cannot
+(defun image-type-from-data (data)
+ "Determine the image type from image data DATA.
+Value is a symbol specifying the image type or nil if type cannot
be determined."
- (unless (file-name-directory file)
- (setq file (concat data-directory file)))
- (setq file (expand-file-name file))
- (let ((header (with-temp-buffer
- (insert-file-contents-literally file nil 0 256)
- (buffer-string)))
- (types image-type-regexps)
+ (let ((types image-type-regexps)
type)
(while (and types (null type))
(let ((regexp (car (car types)))
(image-type (cdr (car types))))
- (when (string-match regexp header)
+ (when (or (and (symbolp image-type)
+ (string-match regexp data))
+ (and (consp image-type)
+ (funcall (car image-type) data)
+ (setq image-type (cdr image-type))))
(setq type image-type))
(setq types (cdr types))))
type))
+;;;###autoload
+(defun image-type-from-file-header (file)
+ "Determine the type of image file FILE from its first few bytes.
+Value is a symbol specifying the image type, or nil if type cannot
+be determined."
+ (unless (file-name-directory file)
+ (setq file (expand-file-name file data-directory)))
+ (setq file (expand-file-name file))
+ (let ((header (with-temp-buffer
+ (set-buffer-multibyte nil)
+ (insert-file-contents-literally file nil 0 256)
+ (buffer-string))))
+ (image-type-from-data header)))
+
+
;;;###autoload
(defun image-type-available-p (type)
"Value is non-nil if image type TYPE is available.
Image types are symbols like `xbm' or `jpeg'."
- (not (null (memq type image-types))))
-
+ (and (fboundp 'init-image-library)
+ (init-image-library type image-library-alist)))
;;;###autoload
-(defun create-image (file &optional type &rest props)
- "Create an image which will be loaded from FILE.
+(defun create-image (file-or-data &optional type data-p &rest props)
+ "Create an image.
+FILE-OR-DATA is an image file name or image data.
Optional TYPE is a symbol describing the image type. If TYPE is omitted
-or nil, try to determine the image file type from its first few bytes.
-If that doesn't work, use FILE's extension.as image type.
+or nil, try to determine the image type from its first few bytes
+of image data. If that doesn't work, and FILE-OR-DATA is a file name,
+use its file extension as image type.
+Optional DATA-P non-nil means FILE-OR-DATA is a string containing image data.
Optional PROPS are additional image attributes to assign to the image,
-like, e.g. `:heuristic-mask t'.
+like, e.g. `:mask MASK'.
Value is the image created, or nil if images of type TYPE are not supported."
- (unless (stringp file)
- (error "Invalid image file name %s" file))
- (unless (or type
- (setq type (image-type-from-file-header file)))
- (let ((extension (file-name-extension file)))
- (unless extension
- (error "Cannot determine image type"))
- (setq type (intern extension))))
+ (when (and (not data-p) (not (stringp file-or-data)))
+ (error "Invalid image file name `%s'" file-or-data))
+ (cond ((null data-p)
+ ;; FILE-OR-DATA is a file name.
+ (unless (or type
+ (setq type (image-type-from-file-header file-or-data)))
+ (let ((extension (file-name-extension file-or-data)))
+ (unless extension
+ (error "Cannot determine image type"))
+ (setq type (intern extension)))))
+ (t
+ ;; FILE-OR-DATA contains image data.
+ (unless type
+ (setq type (image-type-from-data file-or-data)))))
+ (unless type
+ (error "Cannot determine image type"))
(unless (symbolp type)
- (error "Invalid image type %s" type))
+ (error "Invalid image type `%s'" type))
(when (image-type-available-p type)
- (append (list 'image :type type :file file) props)))
+ (append (list 'image :type type (if data-p :data :file) file-or-data)
+ props)))
;;;###autoload
-(defun put-image (image pos &optional buffer area)
- "Put image IMAGE in front of POS in BUFFER.
+(defun put-image (image pos &optional string area)
+ "Put image IMAGE in front of POS in the current buffer.
IMAGE must be an image created with `create-image' or `defimage'.
+IMAGE is displayed by putting an overlay into the current buffer with a
+`before-string' STRING that has a `display' property whose value is the
+image. STRING is defaulted if you omit it.
POS may be an integer or marker.
-BUFFER nil or omitted means use the current buffer.
+AREA is where to display the image. AREA nil or omitted means
+display it in the text area, a value of `left-margin' means
+display it in the left marginal area, a value of `right-margin'
+means display it in the right marginal area."
+ (unless string (setq string "x"))
+ (let ((buffer (current-buffer)))
+ (unless (eq (car-safe image) 'image)
+ (error "Not an image: %s" image))
+ (unless (or (null area) (memq area '(left-margin right-margin)))
+ (error "Invalid area %s" area))
+ (setq string (copy-sequence string))
+ (let ((overlay (make-overlay pos pos buffer))
+ (prop (if (null area) image (list (list 'margin area) image))))
+ (put-text-property 0 (length string) 'display prop string)
+ (overlay-put overlay 'put-image t)
+ (overlay-put overlay 'before-string string))))
+
+
+;;;###autoload
+(defun insert-image (image &optional string area slice)
+ "Insert IMAGE into current buffer at point.
+IMAGE is displayed by inserting STRING into the current buffer
+with a `display' property whose value is the image. STRING is
+defaulted if you omit it.
AREA is where to display the image. AREA nil or omitted means
display it in the text area, a value of `left-margin' means
display it in the left marginal area, a value of `right-margin'
means display it in the right marginal area.
-IMAGE is displayed by putting an overlay into BUFFER with a
-`before-string' that has a `display' property whose value is the
-image."
- (unless buffer
- (setq buffer (current-buffer)))
- (unless (eq (car image) 'image)
+SLICE specifies slice of IMAGE to insert. SLICE nil or omitted
+means insert whole image. SLICE is a list (X Y WIDTH HEIGHT)
+specifying the X and Y positions and WIDTH and HEIGHT of image area
+to insert. A float value 0.0 - 1.0 means relative to the width or
+height of the image; integer values are taken as pixel values."
+ ;; Use a space as least likely to cause trouble when it's a hidden
+ ;; character in the buffer.
+ (unless string (setq string " "))
+ (unless (eq (car-safe image) 'image)
(error "Not an image: %s" image))
(unless (or (null area) (memq area '(left-margin right-margin)))
(error "Invalid area %s" area))
- (let ((overlay (make-overlay pos pos buffer))
- (string (make-string 1 ?x))
- (prop (if (null area) image (cons area image))))
- (put-text-property 0 1 'display prop string)
- (overlay-put overlay 'put-image t)
- (overlay-put overlay 'before-string string)))
-
-
-;;;###autoload
-(defun insert-image (image &optional area)
+ (if area
+ (setq image (list (list 'margin area) image))
+ ;; Cons up a new spec equal but not eq to `image' so that
+ ;; inserting it twice in a row (adjacently) displays two copies of
+ ;; the image. Don't try to avoid this by looking at the display
+ ;; properties on either side so that we DTRT more often with
+ ;; cut-and-paste. (Yanking killed image text next to another copy
+ ;; of it loses anyway.)
+ (setq image (cons 'image (cdr image))))
+ (let ((start (point)))
+ (insert string)
+ (add-text-properties start (point)
+ `(display ,(if slice
+ (list (cons 'slice slice) image)
+ image) rear-nonsticky (display)))))
+
+
+(defun insert-sliced-image (image &optional string area rows cols)
"Insert IMAGE into current buffer at point.
+IMAGE is displayed by inserting STRING into the current buffer
+with a `display' property whose value is the image. STRING is
+defaulted if you omit it.
AREA is where to display the image. AREA nil or omitted means
display it in the text area, a value of `left-margin' means
display it in the left marginal area, a value of `right-margin'
means display it in the right marginal area.
-IMAGE is displayed by inserting an \"x\" into the current buffer
-having a `display' property whose value is the image."
- (unless (eq (car image) 'image)
+The image is automatically split into ROW x COLS slices."
+ (unless string (setq string " "))
+ (unless (eq (car-safe image) 'image)
(error "Not an image: %s" image))
(unless (or (null area) (memq area '(left-margin right-margin)))
(error "Invalid area %s" area))
- (insert "x")
- (add-text-properties (1- (point)) (point)
- (list 'display (if (null area) image (cons area image))
- 'rear-nonsticky (list 'display))))
-
+ (if area
+ (setq image (list (list 'margin area) image))
+ ;; Cons up a new spec equal but not eq to `image' so that
+ ;; inserting it twice in a row (adjacently) displays two copies of
+ ;; the image. Don't try to avoid this by looking at the display
+ ;; properties on either side so that we DTRT more often with
+ ;; cut-and-paste. (Yanking killed image text next to another copy
+ ;; of it loses anyway.)
+ (setq image (cons 'image (cdr image))))
+ (let ((x 0.0) (dx (/ 1.0001 (or cols 1)))
+ (y 0.0) (dy (/ 1.0001 (or rows 1))))
+ (while (< y 1.0)
+ (while (< x 1.0)
+ (let ((start (point)))
+ (insert string)
+ (add-text-properties start (point)
+ `(display ,(list (list 'slice x y dx dy) image)
+ rear-nonsticky (display)))
+ (setq x (+ x dx))))
+ (setq x 0.0
+ y (+ y dy))
+ (insert (propertize "\n" 'line-height 0)))))
+
+
;;;###autoload
(defun remove-images (start end &optional buffer)
(while overlays
(let ((overlay (car overlays)))
(when (overlay-get overlay 'put-image)
- (delete-overlay overlay)
- (setq overlays (cdr overlays)))))))
+ (delete-overlay overlay)))
+ (setq overlays (cdr overlays)))))
+
+
+;;;###autoload
+(defun find-image (specs)
+ "Find an image, choosing one of a list of image specifications.
+
+SPECS is a list of image specifications.
+
+Each image specification in SPECS is a property list. The contents of
+a specification are image type dependent. All specifications must at
+least contain the properties `:type TYPE' and either `:file FILE' or
+`:data DATA', where TYPE is a symbol specifying the image type,
+e.g. `xbm', FILE is the file to load the image from, and DATA is a
+string containing the actual image data. The specification whose TYPE
+is supported, and FILE exists, is used to construct the image
+specification to be returned. Return nil if no specification is
+satisfied.
+
+The image is looked for first on `load-path' and then in `data-directory'."
+ (let (image)
+ (while (and specs (null image))
+ (let* ((spec (car specs))
+ (type (plist-get spec :type))
+ (data (plist-get spec :data))
+ (file (plist-get spec :file))
+ found)
+ (when (image-type-available-p type)
+ (cond ((stringp file)
+ (let ((path load-path))
+ (while (and (not found) path)
+ (let ((try-file (expand-file-name file (car path))))
+ (when (file-readable-p try-file)
+ (setq found try-file)))
+ (setq path (cdr path)))
+ (unless found
+ (let ((try-file (expand-file-name file data-directory)))
+ (if (file-readable-p try-file)
+ (setq found try-file))))
+ (if found
+ (setq image
+ (cons 'image (plist-put (copy-sequence spec)
+ :file found))))))
+ ((not (null data))
+ (setq image (cons 'image spec)))))
+ (setq specs (cdr specs))))
+ image))
;;;###autoload
Each image specification in SPECS is a property list. The contents of
a specification are image type dependent. All specifications must at
-least contain the properties `:type TYPE' and `:file FILE', where TYPE
-is a symbol specifying the image type, e.g. `xbm', and FILE is the
-file to load the image from. The first image specification whose TYPE
-is supported, and FILE exists, is used to define SYMBOL.
+least contain the properties `:type TYPE' and either `:file FILE' or
+`:data DATA', where TYPE is a symbol specifying the image type,
+e.g. `xbm', FILE is the file to load the image from, and DATA is a
+string containing the actual image data. The first image
+specification whose TYPE is supported, and FILE exists, is used to
+define SYMBOL.
Example:
(defimage test-image ((:type xpm :file \"~/test1.xpm\")
(:type xbm :file \"~/test1.xbm\")))"
- (let (image)
- (while (and specs (null image))
- (let* ((spec (car specs))
- (type (plist-get spec :type))
- (file (plist-get spec :file)))
- (when (and (image-type-available-p type) (stringp file))
- (setq file (expand-file-name file))
- (unless (file-name-absolute-p file)
- (setq file (concat data-directory "/" file)))
- (when (file-exists-p file)
- (setq image (cons 'image spec))))
- (setq specs (cdr specs))))
- `(defvar ,symbol ',image ,doc)))
+ `(defvar ,symbol (find-image ',specs) ,doc))
(provide 'image)
- ;; image.el ends here.
-
-
-
-
+;;; arch-tag: 8e76a07b-eb48-4f3e-a7a0-1a7ba9f096b3
+;;; image.el ends here