bug#1785: bug#1547: face-font-rescale-alist has no effect

bug#1785: bug#1547: face-font-rescale-alist has no effect

[Chong Yidong]

> What I currently don't understand is that the font rescaling doesn't
> work for the default font in the above case even after
> (clear-face-cache t).  I'm now investigating the reason.

I think the problem here is that the opened font objects are already
stored in the LFACE_FONT entry of the default face.  Note that

M-: (set-face-attribute 'default nil :font (font-spec)) RET

successfully refreshes the face with the correct rescaling.

bug#1785: bug#1547: face-font-rescale-alist has no effect

[Chong Yidong]

> > What I currently don't understand is that the font rescaling doesn't
> > work for the default font in the above case even after
> > (clear-face-cache t).  I'm now investigating the reason.
>
> I think the problem here is that the opened font objects are already
> stored in the LFACE_FONT entry of the default face.  Note that
>
> M-: (set-face-attribute 'default nil :font (font-spec)) RET
>
> successfully refreshes the face with the correct rescaling.

Until a better solution comes along, I propose dealing with this
situation with the following hack in startup.el: check to see if the
init file changed face-font-rescale-alist, and reload the default face
if necessary.

What do you think?

*** trunk/lisp/startup.el.~1.527.~	2009-02-20 10:20:55.000000000 -0500
--- trunk/lisp/startup.el	2009-04-18 00:07:05.000000000 -0400
***************
*** 499,505 ****
  		     (delete (concat "PWD=" pwd)
  			     process-environment)))))
      (setq default-directory (abbreviate-file-name default-directory))
!     (let ((menubar-bindings-done nil))
        (unwind-protect
  	  (command-line)
  	;; Do this again, in case .emacs defined more abbreviations.
--- 499,506 ----
  		     (delete (concat "PWD=" pwd)
  			     process-environment)))))
      (setq default-directory (abbreviate-file-name default-directory))
!     (let ((menubar-bindings-done nil)
! 	  (old-face-font-rescale-alist face-font-rescale-alist))
        (unwind-protect
  	  (command-line)
  	;; Do this again, in case .emacs defined more abbreviations.
***************
*** 540,545 ****
--- 541,551 ----
  		  (not (and initial-window-system
  			    (not noninteractive)
  			    (not (eq initial-window-system 'pc)))))
+ 	  ;; If face-font-rescale-alist has changed, reload the
+ 	  ;; default font.
+ 	  (unless (eq face-font-rescale-alist
+ 		      old-face-font-rescale-alist)
+ 	    (set-face-attribute 'default nil :font (font-spec)))
  	  ;; Modify the initial frame based on what .emacs puts into
  	  ;; ...-frame-alist.
  	  (if (fboundp 'frame-notice-user-settings)

Diff finished.  Sat Apr 18 00:07:09 2009

bug#1785: bug#1547: face-font-rescale-alist has no effect

[Stefan Monnier]

>> > What I currently don't understand is that the font rescaling doesn't
>> > work for the default font in the above case even after
>> > (clear-face-cache t).  I'm now investigating the reason.
>> 
>> I think the problem here is that the opened font objects are already
>> stored in the LFACE_FONT entry of the default face.  Note that
>> 
>> M-: (set-face-attribute 'default nil :font (font-spec)) RET
>> 
>> successfully refreshes the face with the correct rescaling.

> Until a better solution comes along, I propose dealing with this
> situation with the following hack in startup.el: check to see if the
> init file changed face-font-rescale-alist, and reload the default face
> if necessary.

Can't we fix it right and make clear-face-cache refresh the default face
as well?  If the right fix is really too much trouble, then I guess your
workaround is OK, but then it needs to come with a heavy dose of
comments explaining why it's there and how to get rid of it.


        Stefan

bug#1785: bug#1547: face-font-rescale-alist has no effect

[Chong Yidong]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>> Until a better solution comes along, I propose dealing with this
>> situation with the following hack in startup.el: check to see if the
>> init file changed face-font-rescale-alist, and reload the default face
>> if necessary.
>
> Can't we fix it right and make clear-face-cache refresh the default face
> as well?  If the right fix is really too much trouble, then I guess your
> workaround is OK, but then it needs to come with a heavy dose of
> comments explaining why it's there and how to get rid of it.

I think the right fix is to refresh all font objects that have already
been created.  However, there's currently no way to find them.  At
startup, however, I think only the default face has a font object
assigned to it---that's why I suggested this hack.

Yeah, it's a pretty awful hack, but I don't see a better short-term
solution.

bug#1785: bug#1547: face-font-rescale-alist has no effect

[Chong Yidong]

I have checked in the work-around for this bug.  A more comprehenssive
fix can wait till after the release.  In the meantime, I'll downgrade
the bug severity to normal.

bug#1785: bug#1547: face-font-rescale-alist has no effect

[Andrew Hyatt]

"Juanma Barranquero" <lekktu@gmail.com> writes:

> Package: emacs
> Version: 23.0.60
> X-Debbugs-CC: handa@m17n.org
>
> [Just a reminder, so the issue is not lost]
>
> Font rescaling is unimplemented in the new font backend.
>
> It was already discussed on the list:
>
> http://lists.gnu.org/archive/html/emacs-devel/2008-06/msg01155.html

I'm looking at this for Emacs 25, just to see if it can reproduce.  I
believe this is still the case.  Here's how I attempted to reproduce it
(keep in mind I don't have any particular knowledge of this
functionality).

1) Start emacs with "emacs -Q" in a window (X-windows, or other system
capable of handling different fonts)
2) Eval, in the scratch buffer, (add-to-list 'face-font-rescale-alist
(cons (font-at 1) 4.0)).

From the variable docs, I would expect the text to get 4 times bigger
after changing the variable, but instead nothing happens. 

bug#1785: bug#1547: face-font-rescale-alist has no effect

[npostavs]

Andrew Hyatt <ahyatt@gmail.com> writes:
> I'm looking at this for Emacs 25, just to see if it can reproduce.  I
> believe this is still the case.  Here's how I attempted to reproduce it
> (keep in mind I don't have any particular knowledge of this
> functionality).
>
> 1) Start emacs with "emacs -Q" in a window (X-windows, or other system
> capable of handling different fonts)
> 2) Eval, in the scratch buffer, (add-to-list 'face-font-rescale-alist
> (cons (font-at 1) 4.0)).

I think that's not right format for face-font-rescale-alist, the car
should be a string, not a font object.  Doing

   (add-to-list 'face-font-rescale-alist '(".*" . 4.0))

and tnen opening a new frame gives enlarged text in the new frame, and
causes only buffer name in the modeline the original frame to be
enlarged.  Also it looks like the buffer name in the modeline of the new
frame is enlarged twice.  So it mostly works, but there is some
difficulty with the existing faces used in the current frame.

Doing

    emacs -Q --eval "(add-to-list 'face-font-rescale-alist '(\".*\" . 4.0))"

does give enlarged text in the initial frame.

bug#1785: bug#1547: face-font-rescale-alist has no effect

[Andrew Hyatt]

npostavs@users.sourceforge.net writes:

> Andrew Hyatt <ahyatt@gmail.com> writes:
>> I'm looking at this for Emacs 25, just to see if it can reproduce.  I
>> believe this is still the case.  Here's how I attempted to reproduce it
>> (keep in mind I don't have any particular knowledge of this
>> functionality).
>>
>> 1) Start emacs with "emacs -Q" in a window (X-windows, or other system
>> capable of handling different fonts)
>> 2) Eval, in the scratch buffer, (add-to-list 'face-font-rescale-alist
>> (cons (font-at 1) 4.0)).
>
> I think that's not right format for face-font-rescale-alist, the car
> should be a string, not a font object.  Doing
>
>    (add-to-list 'face-font-rescale-alist '(".*" . 4.0))
>
> and tnen opening a new frame gives enlarged text in the new frame, and
> causes only buffer name in the modeline the original frame to be
> enlarged.  Also it looks like the buffer name in the modeline of the new
> frame is enlarged twice.  So it mostly works, but there is some
> difficulty with the existing faces used in the current frame.
>
> Doing
>
>     emacs -Q --eval "(add-to-list 'face-font-rescale-alist '(\".*\" . 4.0))"
>
> does give enlarged text in the initial frame.

Thanks for the information.  I tried this out on a Mac and found that,
with your corrected expression, I was able to see roughly what you see,
with the exception that some faces were not rescaled for some reason,
except when I started it with the rescale list eval'd at emacs start
time.

So, as you note, there are still some bugs here, enough (IMHO) to leave
this open and at the same priority.

bug#1785: bug#1547: face-font-rescale-alist has no effect

[Eli Zaretskii]

> From: Andrew Hyatt <ahyatt@gmail.com>
> Date: Thu, 14 Jul 2016 00:04:16 -0400
> Cc: Juanma Barranquero <lekktu@gmail.com>, 1547@debbugs.gnu.org,
> 	1785@debbugs.gnu.org
> 
> >     emacs -Q --eval "(add-to-list 'face-font-rescale-alist '(\".*\" . 4.0))"
> >
> > does give enlarged text in the initial frame.
> 
> Thanks for the information.  I tried this out on a Mac and found that,
> with your corrected expression, I was able to see roughly what you see,
> with the exception that some faces were not rescaled for some reason,
> except when I started it with the rescale list eval'd at emacs start
> time.
> 
> So, as you note, there are still some bugs here, enough (IMHO) to leave
> this open and at the same priority.

Actually, I'd think the priority should be lowered, as rescaling all
the fonts makes little sense to me.  FWIW.

Of course, if someone wants to work on this, I will gladly help by
whatever advice I can give.

Thanks.

bug#1785: bug#1547: face-font-rescale-alist has no effect

[Lars Ingebrigtsen]

Kenichi Handa <handa@m17n.org> writes:

> In article
> <f7ccd24b0812120253m5f1b4f9en3a23f0ccc26b6b2d@mail.gmail.com>, "Juanma
> Barranquero" <lekktu@gmail.com> writes:
>
>> [Just a reminder, so the issue is not lost]
>
>> Font rescaling is unimplemented in the new font backend.
>
> Thank you for the reminder.  I've just installed a fix.

This was ten years ago, and as far as I can tell, font scaling works
just fine these days.  So I'm closing this bug report.  Please reopen if
there are any further issues that haven't been addressed in the meantime.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no