mirror of
https://git.savannah.gnu.org/git/emacs.git
synced 2024-12-27 10:54:40 +00:00
300 lines
11 KiB
EmacsLisp
300 lines
11 KiB
EmacsLisp
;;; image.el --- image API
|
|
|
|
;; Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
|
|
|
|
;; Maintainer: FSF
|
|
;; Keywords: multimedia
|
|
|
|
;; This file is part of GNU Emacs.
|
|
|
|
;; GNU Emacs is free software; you can redistribute it and/or modify
|
|
;; it under the terms of the GNU General Public License as published by
|
|
;; the Free Software Foundation; either version 2, or (at your option)
|
|
;; any later version.
|
|
|
|
;; GNU Emacs is distributed in the hope that it will be useful,
|
|
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
;; GNU General Public License for more details.
|
|
|
|
;; You should have received a copy of the GNU General Public License
|
|
;; along with GNU Emacs; see the file COPYING. If not, write to the
|
|
;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
|
;; Boston, MA 02111-1307, USA.
|
|
|
|
;;; Commentary:
|
|
|
|
;;; Code:
|
|
|
|
|
|
(defgroup image ()
|
|
"Image support."
|
|
:group 'multimedia)
|
|
|
|
|
|
(defconst image-type-regexps
|
|
'(("\\`/[\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 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-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."
|
|
(let ((types image-type-regexps)
|
|
type)
|
|
(while (and types (null type))
|
|
(let ((regexp (car (car types)))
|
|
(image-type (cdr (car types))))
|
|
(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'."
|
|
(and (boundp 'image-types) (not (null (memq type image-types)))))
|
|
|
|
|
|
;;;###autoload
|
|
(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 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. `:mask MASK'.
|
|
Value is the image created, or nil if images of type TYPE are not supported."
|
|
(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))
|
|
(when (image-type-available-p type)
|
|
(append (list 'image :type type (if data-p :data :file) file-or-data)
|
|
props)))
|
|
|
|
|
|
;;;###autoload
|
|
(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.
|
|
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)
|
|
"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."
|
|
;; 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))
|
|
(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
|
|
;; `image' has the right properties to
|
|
;; mark an intangible field.
|
|
'intangible image
|
|
'rear-nonsticky (list 'display)))))
|
|
|
|
|
|
;;;###autoload
|
|
(defun remove-images (start end &optional buffer)
|
|
"Remove images between START and END in BUFFER.
|
|
Remove only images that were put in BUFFER with calls to `put-image'.
|
|
BUFFER nil or omitted means use the current buffer."
|
|
(unless buffer
|
|
(setq buffer (current-buffer)))
|
|
(let ((overlays (overlays-in start end)))
|
|
(while overlays
|
|
(let ((overlay (car overlays)))
|
|
(when (overlay-get overlay 'put-image)
|
|
(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
|
|
(defmacro defimage (symbol specs &optional doc)
|
|
"Define SYMBOL as an image.
|
|
|
|
SPECS is a list of image specifications. DOC is an optional
|
|
documentation string.
|
|
|
|
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 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\")))"
|
|
`(defvar ,symbol (find-image ',specs) ,doc))
|
|
|
|
|
|
(provide 'image)
|
|
|
|
;;; image.el ends here
|