text properties not applied (almost a bug report, but...)

text properties not applied (almost a bug report, but...)

[Joe Corneli]

In some modes (elisp and mail are two I've tested) this form simply
returns `t', there's no change to the display, and apparently no
change to the buffer.

(set-text-properties (line-beginning-position)
                     (line-end-position)
                     '(face font-lock-keyword-face)
                     (current-buffer))               
                            ^                        ^

                            2                        1
                                                  C-x C-e
                          (get-text-property       
                             (point) 'face)
                          ;=> nil

Is there a way to assert that I really want to set the face,
regardless of the mode the buffer happens to be in (though it seems to
be a bit of a long-shot)?  Or must I switch to fundamental mode to set
the face?  (Note: in CVS emacs of 2005-05-10, switching *back* to
fundamental mode didn't work, but with today's version emacs, that at
least works.)

Re: text properties not applied (almost a bug report, but...)

[Johan Bockgård]

Joe Corneli <jcorneli@math.utexas.edu> writes:

> Is there a way to assert that I really want to set the face,
> regardless of the mode the buffer happens to be in

I doesn't depend on the mode, but on whether font lock is used or not
(font lock uses the face property).

-- 
Johan Bockgård

Re: text properties not applied (almost a bug report, but...)

[Joe Corneli]

Well, I realized that I might as well use overlays.

   I doesn't depend on the mode, but on whether font lock is used or not
   (font lock uses the face property).

I'm not sure this is correct, since if you save my message,
kill the buffer, reopen it, and run `font-lock-fontify-buffer'
then faces change, but the code snippet still changes
the faces when it is run.

Re: text properties not applied (almost a bug report, but...)

[rgb]

>    I doesn't depend on the mode, but on whether font lock is used or not
>    (font lock uses the face property).
>
> I'm not sure this is correct, since if you save my message,
> kill the buffer, reopen it, and run `font-lock-fontify-buffer'
> then faces change, but the code snippet still changes
> the faces when it is run.

When font lock is turned on, application of a text property
is seen as a change that causes the text to be re-fontified.
So your setting of the text face is almost immediately erased.
If you execute your code in a buffer with font-lock turned off
your face setting will persist.