Re: image instance/specifier/instantiator

[Hrvoje Niksic <hniksic@srce.hr>]

Lars Magne Ingebrigtsen <larsi@gnus.org> writes:

> > BTW, why do you create image specifiers at all?  I don't think you
> > need to do that -- an instantiator should suffice.
> 
> Er...  I though
> 
>       (make-image-specifier
>        (vector (intern type) :data (buffer-string)))
> 
> was the simplest way to create an image?

Well, it creates an image specifier, which contains information how
the image should be displayed on various devices.  In XEmacs parlance,
the actual image in buffer is in called a "glyph", and the easiest way
to create it is using an instantiator, without mucking with image
specifiers at all (leave that to the internal code.)  For instance:

;; I like backquotes
(setq my-glyph (make-glyph `[,(intern type) :data ,(buffer-string)]))

Now, you can attach `my-glyph' at the beginning or an end of an extent
(this is considered "low-level"), or feed it to `make-annotation'.
The specifier will, of course, still be there:

(glyph-image my-glyph)
  => #<image-specifier global=((x) . [gif :file "/home/srce/hniksic/pics/kreten.gif" :data "GIF87a..."]>

XEmacs' interface to images may be a bit confusing at first; if you
don't understand how it works, feel free to ask.  Also, I've found
that chapter in the manual quite well written (but that's me.)

-- 
Hrvoje Niksic <hniksic@srce.hr> | Student at FER Zagreb, Croatia
--------------------------------+--------------------------------
You're never alone with schizophrenia.