Re: image-load-path/load-path function

[Reiner Steib <reinersteib+gmane@imap.cc>]

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On Fri, Mar 03 2006, Bill Wohler wrote:

> I think we're ready to move it to image.el. Let me know if you think I
> should proceed.
>
> I think the name image-load-path would be fine: If you ask for the
> variable image-load-path, you get the image load path, if you ask for
> the function image-load-path, you get the image load path. Seems
> consistent. What do you think?

Maybe `image-relative-load-path' or `image-load-path-relative' to make
it more clear?

> (defun mh-image-load-path (library image &optional path)
>   "Return a suitable search path for images of LIBRARY.
>
> Images for LIBRARY are searched for in \"../../etc/images\" and
> \"../etc/images\" relative to the files in \"lisp/LIBRARY\", in
> `image-load-path', or in `load-path'.
>
> This function returns value of `load-path' augmented with the
> path to IMAGE.  If PATH is given, it is used instead of
> `load-path'."

Adding a calling example to doc string won't hurt.  Maybe emphasize
that IMAGE must include the extension, e.g. .xpm (maybe not necessary
when we give an example).

>   (let ((mh-image-directory))
[...]
>      ((let (mh-library-name d1ei d2ei)

The local variables mh-image-directory and mh-library-name should have
a non-prefixed name e.g. image-dir and library-name.  This would also
make synching more easy.  See the attached patch against
emacs/lisp/mh-e/mh-utils.el.

>     (unless (file-exists-p mh-image-directory)
>       (error "Directory %s in mh-image-directory does not exist"
> 	     mh-image-directory))
>     (unless (file-exists-p (expand-file-name image mh-image-directory))
>       (error "Directory %s in mh-image-directory does not contain image %s"
>              mh-image-directory image))

As mh-image-directory cannot be not a user-specified directory
anymore, I doubt that these errors are very useful.  But if you'd like
to keep these two `error' calls, we should add an optional no-error
argument as suggested by Katsumi Yamaoka.  We would set this to t in
Gnus and the function would use `message' or `error' depending on its
value.

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

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--- mh-utils.el	03 Mar 2006 13:59:57 +0100	1.57
+++ mh-utils.el	03 Mar 2006 17:34:28 +0100	
@@ -94,25 +94,25 @@
 `load-path'."
   (unless library (error "No library specified"))
   (unless image   (error "No image specified"))
-  (let ((mh-image-directory))
+  (let ((image-dir))
     (cond
      ;; Try relative setting.
-     ((let (mh-library-name d1ei d2ei)
+     ((let (library-name d1ei d2ei)
         ;; First, find library in the load-path.
-        (setq mh-library-name (locate-library library))
-        (if (not mh-library-name)
+        (setq library-name (locate-library library))
+        (if (not library-name)
             (error "Cannot find library %s in load-path" library))
-        ;; And then set mh-image-directory relative to that.
+        ;; And then set image-dir relative to that.
         (setq
          ;; Go down 2 levels.
          d2ei (expand-file-name
-               (concat (file-name-directory mh-library-name)
+               (concat (file-name-directory library-name)
                        "../../etc/images"))
          ;; Go down 1 level.
          d1ei (expand-file-name
-               (concat (file-name-directory mh-library-name)
+               (concat (file-name-directory library-name)
                        "../etc/images")))
-        (setq mh-image-directory
+        (setq image-dir
               ;; Set it to nil if image is not found.
               (cond ((file-exists-p (expand-file-name image d2ei)) d2ei)
                     ((file-exists-p (expand-file-name image d1ei)) d1ei)))))
@@ -125,7 +125,7 @@
                   (locate-library image)))
             parent)
         ;; Since the image might be in a nested directory
-        ;; (for example, mail/attach.pbm), adjust `mh-image-directory'
+        ;; (for example, mail/attach.pbm), adjust `image-dir'
         ;; accordingly.
         (and dir
              (setq dir (file-name-directory dir))
@@ -133,24 +133,24 @@
                (while (setq parent (file-name-directory img))
                  (setq img (directory-file-name parent)
                        dir (expand-file-name "../" dir)))
-               (setq mh-image-directory dir))))))
+               (setq image-dir dir))))))
     ;;
-    (unless (file-exists-p mh-image-directory)
-      (error "Directory %s in mh-image-directory does not exist"
-	     mh-image-directory))
-    (unless (file-exists-p (expand-file-name image mh-image-directory))
-      (error "Directory %s in mh-image-directory does not contain image %s"
-             mh-image-directory image))
+    (unless (file-exists-p image-dir)
+      (error "Directory %s in image-dir does not exist"
+	     image-dir))
+    (unless (file-exists-p (expand-file-name image image-dir))
+      (error "Directory %s in image-dir does not contain image %s"
+             image-dir image))
     ;; Return augmented `image-load-path' or `load-path'.
     (cond ((and path (symbolp path))
-           (nconc (list mh-image-directory)
-                  (delete mh-image-directory
+           (nconc (list image-dir)
+                  (delete image-dir
                           (if (boundp path)
                               (copy-sequence (symbol-value path))
                             nil))))
           (t
-           (nconc (list mh-image-directory)
-                  (delete mh-image-directory
+           (nconc (list image-dir)
+                  (delete image-dir
                           (copy-sequence load-path)))))))
 
 ;;;###mh-autoload