(ucs-fragment-8859): Don't modify

[bpt/emacs.git] / lisp / image.el

diff --git a/lisp/image.el b/lisp/image.el
index 9683443..ac1ef55 100644 (file)
--- a/lisp/image.el
+++ b/lisp/image.el
@@ -1,6 +1,8 @@
 ;;; image.el --- image API
 
-;; Copyright (C) 1998, 1999, 2000 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.
@@ -24,18 +26,49 @@
 
 ;;; 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
@@ -48,7 +81,11 @@ be determined."
     (while (and types (null type))
       (let ((regexp (car (car types)))
            (image-type (cdr (car types))))
-       (when (string-match regexp data)
+       (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))
@@ -63,6 +100,7 @@ be determined."
     (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)))
@@ -82,10 +120,10 @@ 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.
+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."
   (when (and (not data-p) (not (stringp file-or-data)))
     (error "Invalid image file name `%s'" file-or-data))
@@ -165,11 +203,7 @@ means display it in the right marginal area."
   (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)))))
+                        `(display ,image rear-nonsticky (display)))))
 
 
 ;;;###autoload