Change indian-1-column charset to indian-glyph charset.

[gnu-emacs] / lisp / image.el

diff --git a/lisp/image.el b/lisp/image.el
index 0e507d2ed3cbe94165e6a06f85101f063b667013..e4c2387d78e3a86b0e89fd74d1ae211bebe16b55 100644 (file)
--- a/lisp/image.el
+++ b/lisp/image.el
@@ -1,6 +1,6 @@
 ;;; image.el --- image API
 
-;; Copyright (C) 1998, 1999, 2000 Free Software Foundation, Inc.
+;; Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
 ;; Keywords: multimedia
 
 ;; This file is part of GNU Emacs.
@@ -24,18 +24,48 @@
 
 ;;; 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."
+  (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" (substring data i (+ i nbytes)))))
+           (setq i (+ i 1 nbytes))))))))
 
 
 ;;;###autoload
@@ -48,7 +78,11 @@ 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))
@@ -82,10 +116,10 @@ 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))
@@ -225,7 +259,8 @@ The image is looked for first on `load-path' and then in `data-directory'."
                           (setq found try-file))))
                   (if found
                       (setq image
-                            (cons 'image (plist-put spec :file found))))))
+                            (cons 'image (plist-put (copy-sequence spec)
+                                                    :file found))))))
                ((not (null data))
                 (setq image (cons 'image spec)))))
        (setq specs (cdr specs))))