* bug#14629: 24.3.50; (elisp) `Face Attributes', :font -> "font object"
@ 2013-06-16 6:01 Drew Adams
2013-06-17 15:14 ` Kenichi Handa
0 siblings, 1 reply; 6+ messages in thread
From: Drew Adams @ 2013-06-16 6:01 UTC (permalink / raw)
To: 14629
The description of face attribute :font is incomprehensible.
It says that the value should be a "font object". What is that, you
ask? Well, it says to see node `Font Selection' to find out. But that
node says nothing about a "font object".
I have no idea what it is, that is, what possible values attribute :font
can have. I know about the frame parameter `font', whose value is an
XLFD string (AFAICT). But I have no idea what :font can be set to.
Not only that, but if I try to guess from using `M-x customize-face',
there is no `Font' attribute. There are only attributes `Font Family'
and `Font Foundry'.
Please give us a clue what :font is - what forms its value takes.
In GNU Emacs 24.3.50.1 (i686-pc-mingw32)
of 2013-06-13 on ODIEONE
Bzr revision: 112978 xfq.free@gmail.com-20130613224333-3yfl8navh3c1vmxy
Windowing system distributor `Microsoft Corp.', version 6.1.7601
Configured using:
`configure --prefix=/c/Devel/emacs/binary --enable-checking=yes,glyphs
CFLAGS='-O0 -g3' CPPFLAGS='-Ic:/Devel/emacs/include'
LDFLAGS='-Lc:/Devel/emacs/lib''
^ permalink raw reply [flat|nested] 6+ messages in thread
* bug#14629: 24.3.50; (elisp) `Face Attributes', :font -> "font object"
2013-06-16 6:01 bug#14629: 24.3.50; (elisp) `Face Attributes', :font -> "font object" Drew Adams
@ 2013-06-17 15:14 ` Kenichi Handa
2013-06-17 16:37 ` Drew Adams
0 siblings, 1 reply; 6+ messages in thread
From: Kenichi Handa @ 2013-06-17 15:14 UTC (permalink / raw)
To: 14629
> From: Drew Adams <drew.adams@oracle.com>
[...]
> The description of face attribute :font is incomprehensible.
> It says that the value should be a "font object". What is that, you
> ask? Well, it says to see node `Font Selection' to find out. But
> that
> node says nothing about a "font object".
I've just committed the attached fix.
> I have no idea what it is, that is, what possible values attribute
> :font
> can have. I know about the frame parameter `font', whose value is an
> XLFD string (AFAICT). But I have no idea what :font can be set to.
You can also specify a font name, which is written in Info
as below:
When specifying this attribute using `set-face-attribute' (*note
Attribute Functions::), you may also supply a font spec, a font
entity, or a string. Emacs converts such values to an appropriate
font object, and stores that font object as the actual attribute
value. If you specify a string, the contents of the string should
be a font name (*note Fonts: (emacs)Fonts.); if the font name is
an XLFD containing wildcards, Emacs chooses the first font
matching those wildcards.
> Not only that, but if I try to guess from using `M-x customize-face',
> there is no `Font' attribute. There are only attributes `Font Family'
> and `Font Foundry'.
Ah, perhaps customize-face should be improved.
---
Kenichi Handa
handa@gnu.org
=== modified file 'doc/lispref/display.texi'
--- doc/lispref/display.texi 2013-04-06 07:39:48 +0000
+++ doc/lispref/display.texi 2013-06-17 15:00:04 +0000
@@ -2126,7 +2126,8 @@
@item :font
The font used to display the face. Its value should be a font object.
-@xref{Font Selection}, for information about font objects.
+@xref{Low-Level Font}, for information about font objects, font specs,
+and font entities.
When specifying this attribute using @code{set-face-attribute}
(@pxref{Attribute Functions}), you may also supply a font spec, a font
@@ -3260,7 +3261,9 @@
properties are intermediate between a font object and a font spec:
like a font object, and unlike a font spec, it refers to a single,
specific font. Unlike a font object, creating a font entity does not
-load the contents of that font into computer memory.
+load the contents of that font into computer memory. Emacs may open
+multiple font objects of different sizes from a single font entity
+referring to a scalable font.
@defun find-font font-spec &optional frame
This function returns a font entity that best matches the font spec
^ permalink raw reply [flat|nested] 6+ messages in thread
* bug#14629: 24.3.50; (elisp) `Face Attributes', :font -> "font object"
2013-06-17 15:14 ` Kenichi Handa
@ 2013-06-17 16:37 ` Drew Adams
2013-06-17 20:06 ` Drew Adams
2019-11-02 15:01 ` Eli Zaretskii
0 siblings, 2 replies; 6+ messages in thread
From: Drew Adams @ 2013-06-17 16:37 UTC (permalink / raw)
To: Kenichi Handa, 14629
[Resending - forgot to include the bug list in my reply.]
> > The description of face attribute :font is incomprehensible.
>
> > It says that the value should be a "font object". What is that, you
> > ask? Well, it says to see node `Font Selection' to find out. But
> > that node says nothing about a "font object".
>
> I've just committed the attached fix.
Thanks for working on this so promptly.
> > I have no idea what it is, that is, what possible values attribute
> > :font can have. I know about the frame parameter `font', whose
> > value is an XLFD string (AFAICT). But I have no idea what :font
> > can be set to.
>
> You can also specify a font name,
You say "also". In addition to what? What else can one provide here,
besides a font name?
> which is written in Info as below:
>
> When specifying this attribute using `set-face-attribute'
But I am not using `set-face-attribute'. What then?
This node is about face attributes generally. I'm specifying them
this way, for instance:
(propertize MYFONT
'face
(list :foundry FOUNDRY :family FAMILY :weight WEIGHT
:slant SLANT :width WIDTH))
That uses text property `face', specifying certain face attributes,
which this node presumably describes. And in general it works.
Text property `face' is no doubt not the same thing as a face.
But what about a face attribute? Doesn't a face attribute apply
to both a face and the `face' text property?
And again, using the attributes with a `face' text property does work
for some of the attributes. Is it not a bug that it does not work
for all of them? If not, it is a doc bug that we do not specify
which face attributes you can use with a `face' text property.
> (*note Attribute Functions::), you may also supply a font spec,
What is a font spec? Is it something like the XLFD string above?
> a font entity,
What is a font entity?
> or a string.
What kind of string? What's the format?
> Emacs converts such values to an appropriate font object,
As I mentioned before, "font object" seems to be defined nowhere -
at least not in the node cross-referenced for it. What is a font
object?
> and stores that font object as the actual attribute
> value.
Beyond the doc, there is a real product bug - see #14634.
In particular, attribute :font seems to have *no effect* when you do,
for example, this:
(propertize myfont 'face (list :font myfont))
> > Not only that, but if I try to guess from using
> > `M-x customize-face', there is no `Font' attribute. There are
> > only attributes `Font Family' and `Font Foundry'.
>
> Ah, perhaps customize-face should be improved.
Yes.
But the problem seems to be greater than Customize. See above:
attribute :font has no effect in at least some contexts (beyond
Customize). It's not clear what contexts it actually has the
documented effect. Is it only for `set-face-attribute'? That would
mean that it does not apply to contexts such as using text property
`face'.
> === modified file 'doc/lispref/display.texi'
Thanks for the patch, but sorry, but I do not see how it is relevant
to this bug.
^ permalink raw reply [flat|nested] 6+ messages in thread
* bug#14629: 24.3.50; (elisp) `Face Attributes', :font -> "font object"
2013-06-17 16:37 ` Drew Adams
@ 2013-06-17 20:06 ` Drew Adams
2019-11-02 15:01 ` Eli Zaretskii
1 sibling, 0 replies; 6+ messages in thread
From: Drew Adams @ 2013-06-17 20:06 UTC (permalink / raw)
To: Kenichi Handa, 14629
Also, what about adding face attributes that correspond to each
of the font properties listed in (emacs) `Windows Fonts'?
Node (elisp) `Face Attributes' already makes clear that:
"Some of these attributes are meaningful only on certain kinds
of displays. If your display cannot handle a certain attribute,
the attribute is ignored."
IOW, what about adding these?
:adstyle
:registry
:spacing
:script
:antialias
^ permalink raw reply [flat|nested] 6+ messages in thread
* bug#14629: 24.3.50; (elisp) `Face Attributes', :font -> "font object"
2013-06-17 16:37 ` Drew Adams
2013-06-17 20:06 ` Drew Adams
@ 2019-11-02 15:01 ` Eli Zaretskii
2020-09-21 14:30 ` Lars Ingebrigtsen
1 sibling, 1 reply; 6+ messages in thread
From: Eli Zaretskii @ 2019-11-02 15:01 UTC (permalink / raw)
To: Drew Adams; +Cc: 14629
> Date: Mon, 17 Jun 2013 09:37:56 -0700 (PDT)
> From: Drew Adams <drew.adams@oracle.com>
>
> > (*note Attribute Functions::), you may also supply a font spec,
>
> What is a font spec? Is it something like the XLFD string above?
>
> > a font entity,
>
> What is a font entity?
There's a cross-reference there to "Low-Level Font", which tells you
something about these objects.
> > or a string.
>
> What kind of string? What's the format?
There's a cross-reference there to "Fonts" in the Emacs manual, which
answers that question.
> > Emacs converts such values to an appropriate font object,
>
> As I mentioned before, "font object" seems to be defined nowhere -
> at least not in the node cross-referenced for it. What is a font
> object?
See above.
> Beyond the doc, there is a real product bug - see #14634.
> In particular, attribute :font seems to have *no effect* when you do,
> for example, this:
>
> (propertize myfont 'face (list :font myfont))
What is 'myfont' in this example?
^ permalink raw reply [flat|nested] 6+ messages in thread
* bug#14629: 24.3.50; (elisp) `Face Attributes', :font -> "font object"
2019-11-02 15:01 ` Eli Zaretskii
@ 2020-09-21 14:30 ` Lars Ingebrigtsen
0 siblings, 0 replies; 6+ messages in thread
From: Lars Ingebrigtsen @ 2020-09-21 14:30 UTC (permalink / raw)
To: Eli Zaretskii; +Cc: 14629
Eli Zaretskii <eliz@gnu.org> writes:
>> Date: Mon, 17 Jun 2013 09:37:56 -0700 (PDT)
>> From: Drew Adams <drew.adams@oracle.com>
>>
>> > (*note Attribute Functions::), you may also supply a font spec,
>>
>> What is a font spec? Is it something like the XLFD string above?
>>
>> > a font entity,
>>
>> What is a font entity?
>
> There's a cross-reference there to "Low-Level Font", which tells you
> something about these objects.
The documentation here looks OK to me now after the changes, so I'm
closing this bug report.
--
(domestic pets only, the antidote for overdose, milk.)
bloggy blog: http://lars.ingebrigtsen.no
^ permalink raw reply [flat|nested] 6+ messages in thread
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2013-06-16 6:01 bug#14629: 24.3.50; (elisp) `Face Attributes', :font -> "font object" Drew Adams
2013-06-17 15:14 ` Kenichi Handa
2013-06-17 16:37 ` Drew Adams
2013-06-17 20:06 ` Drew Adams
2019-11-02 15:01 ` Eli Zaretskii
2020-09-21 14:30 ` Lars Ingebrigtsen
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