;;; image.el --- image API
-;; Copyright (C) 1998, 1999 Free Software Foundation, Inc.
+;; Copyright (C) 1998, 1999, 2000, 2001 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 ")
+
+
+(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 (+ i nbytes)))))
+ (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 (boundp 'image-types) (not (null (memq type image-types)))))
;;;###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 string &optional area)
+(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.
+image. STRING is defaulted if you omit it.
POS may be an integer or marker.
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 image) 'image)
+ (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))
;;;###autoload
-(defun insert-image (image string &optional area)
+(defun insert-image (image &optional string area)
"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.
+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."
- (unless (eq (car image) 'image)
+ ;; 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))
- (when area
- (setq image (list (list 'margin area) image)))
+ (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)
- (list 'display image
- 'rear-nonsticky (list 'display)))))
-
+ `(display ,image rear-nonsticky (display)))))
+
;;;###autoload
(defun remove-images (start end &optional buffer)
(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
(defmacro defimage (symbol specs &optional doc)
"Define SYMBOL as an image.
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 data-directory))
- (when (file-readable-p file)
- (setq image (cons 'image (plist-put spec :file file)))))
- (setq specs (cdr specs))))
- `(defvar ,symbol ',image ,doc)))
+ `(defvar ,symbol (find-image ',specs) ,doc))
(provide 'image)
- ;; image.el ends here.
-
-
-
-
+;;; image.el ends here
HCoop / bpt / emacs.git / blobdiff