bug#2659: 23.0.91; set-face-attribute :height float on a Mac

bug#2659: 23.0.91; set-face-attribute :height float on a Mac

[Alex Schröder]

The following results in an error:

(set-face-attribute 'default nil :height 1.1)

Debugger entered--Lisp error: (error "Invalid default face height" 1.1)
  internal-set-lisp-face-attribute(default :height 1.1 0)
  set-face-attribute(default nil :height 1.1)

I think it should not because the doc string says:

`:height'

VALUE must be either an integer specifying the height of the font to use
in 1/10 pt, a floating point number specifying the amount by which to
scale any underlying face, or a function, which is called with the old
height (from the underlying face), and should return the new height.

Either that, or the doc string must be improved. :)

I'm using Apple's Mac OS 10.3.9.


In GNU Emacs 23.0.91.1 (powerpc-apple-darwin7.9.0, NS apple-appkit-743.43)
 of 2009-03-13 on Alpinobombus.local
Windowing system distributor `Apple', version 10.3.743
configured using `configure  '--with-ns''

Important settings:
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  value of $LC_COLLATE: nil
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  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: nil
  value of $XMODIFIERS: nil
  locale-coding-system: nil
  default-enable-multibyte-characters: t

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
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bug#2659: 23.0.91; set-face-attribute :height float on a Mac

[Stefan Monnier]

> Debugger entered--Lisp error: (error "Invalid default face height" 1.1)

This says that you can't specify "1.1 times the underlying face" because
the default face as no underlying face.


        Stefan

bug#2659: 23.0.91; set-face-attribute :height float on a Mac

[Alex Schröder]

Ah. I misunderstood the doc string, then. Can we improve the docstring
and find another way to say "underlying face"? The word underlying
doesn't appear in the Elisp manual index. When I read your answer I
thought that underlying faces are the faces are the faces I inherit
from. But when I look at (elisp) Face Attributes I see the following:

`:inherit'
     The name of a face from which to inherit attributes, or a list of
     face names.  Attributes from inherited faces are merged into the
     face like an underlying face would be, with higher priority than
     underlying faces.  If a list of faces is used, attributes from
     faces earlier in the list override those from later faces.

Apparently there is a difference between inheritance and underlying
that I don't understand.



On Fri, Mar 13, 2009 at 17:08, Stefan Monnier <monnier@iro.umontreal.ca> wrote:
>> Debugger entered--Lisp error: (error "Invalid default face height" 1.1)
>
> This says that you can't specify "1.1 times the underlying face" because
> the default face as no underlying face.
>
>
>        Stefan
>

bug#2659: 23.0.91; set-face-attribute :height float on a Mac

[Miles Bader]

Stefan Monnier <monnier@IRO.UMontreal.CA> writes:
>> Debugger entered--Lisp error: (error "Invalid default face height" 1.1)
>
> This says that you can't specify "1.1 times the underlying face" because
> the default face as no underlying face.

Note that because the default face height is always absolute and fixed,
it should be easy enough to do what you want by retrieving the current
height and multiplying it yourself.

e.g.
(set-face-attribute 'default nil
                    :height (truncate
                             (* (face-attribute 'default :height) 1.1)))

-Miles

-- 
Virtues, n. pl. Certain abstentions.

bug#2659: 23.0.91; set-face-attribute :height float on a Mac

[Glenn Morris]

Version: 23.3

Tried to improve the doc-string of set-face-attribute, and the error message.
The lispref already seems pretty clear on this.