Re: About `image-load-path'

[Reiner Steib]

On Sat, Sep 24 2005, David Kastrup wrote:

> Maybe image-load-path could also allow symbols.  Then one could make
> its last element the symbol `load-path', and thus it would be able to
> track changes of load-path.

`image-load-path' already allows symbols (rev. 1.50 of `image.el').  I
think making it customizable would make sense if paths like
(file-name-as-directory (expand-file-name "images" data-directory) do
not end up in the custom file in *expanded* form.

Instead of...

'(image-load-path
  (quote ("/some/user/image/dir"
          "/some/path/to/emacs/prefix/share/emacs/22.0.50/etc/images/"
          data-directory
          load-path)))

...  it should read...

'(image-load-path
  (quote ("/some/user/image/dir"
          (file-name-as-directory (expand-file-name "images" data-directory))
          data-directory
          load-path)))

... in the custom file.

Here's an attempt (maybe my tests are not the most suitable ones?) to
achieve this:

--8<---------------cut here---------------start------------->8---
--- image.el    19 Sep 2005 11:36:26 +0200      1.50
+++ image.el    22 Sep 2005 14:52:09 +0200      
@@ -49,15 +49,18 @@
 with one argument, a string containing the image data.  If PREDICATE returns
 a non-nil value, TYPE is the image's type.")

-(defvar image-load-path
-  (list (file-name-as-directory (expand-file-name "images" data-directory))
+(defcustom image-load-path
+  (list '(file-name-as-directory (expand-file-name "images" data-directory))
        'data-directory 'load-path)
   "List of locations in which to search for image files.
 If an element is a string, it defines a directory to search.
 If an element is a variable symbol whose value is a string, that
 value defines a directory to search.
 If an element is a variable symbol whose value is a list, the
-value is used as a list of directories to search.")
+value is used as a list of directories to search."
+  :type '(repeat (choice (string)
+                        (sexp)
+                        (symbol))))

 (defun image-jpeg-p (data)
   "Value is non-nil if DATA, a string, consists of JFIF image data.
@@ -297,7 +300,11 @@
                 (setq pathname (expand-file-name file element)))))
         ((consp element)
          (if (setq pathname (image-search-load-path file element))
-             (setq found t))))))
+             (setq found t)))))
+       ((or (and (consp element) (fboundp (car element)))
+           (fboundp element))
+       (let ((string) (eval element))
+         (and (stringp string) string))))
       (setq path (cdr path)))
     (if found pathname)))
--8<---------------cut here---------------end--------------->8---

Bye, Reiner.
-- 
       ,,,
      (o o)
---ooO-(_)-Ooo---  |  PGP key available  |  http://rsteib.home.pages.de/