A bug set-face-background

A bug set-face-background

[Kazu Yamamoto]

Hi,

Recent changes to Emacs HEAD made set-face-background strange.

The following function sets the foreground of mode-line to "white":

	(set-face-foreground 'mode-line "white")

But then the following function does not set the background of
mode-lien to "white" and turns the foreground to the original.

	(set-face-background 'mode-line "white")

This bug does not exist at least on Nov 1.

--Kazu

Re: A bug set-face-background

[Aaron Ecay]

Hi Kazu,

I think this is a manifestation of bug 15815.

http://debbugs.gnu.org/cgi/bugreport.cgi?bug=15815

-- 
Aaron Ecay

Re: A bug set-face-background

[Michael Heerdegen]

Hi Kazu,

> Recent changes to Emacs HEAD made set-face-background strange.
>
> The following function sets the foreground of mode-line to "white":
>
> 	(set-face-foreground 'mode-line "white")
>
> But then the following function does not set the background of
> mode-lien to "white" and turns the foreground to the original.
>
> 	(set-face-background 'mode-line "white")
>
> This bug does not exist at least on Nov 1.

I experience that since some time, Emacs display "overrides" faces that
differ only slightly from the background and displays them in black or
white instead, to keep things readable.  What you see is presumably a
symptom of this behavior.


Regards,

Michael.

Re: A bug set-face-background

[Kazu Yamamoto]

Hi Michael,

> I experience that since some time, Emacs display "overrides" faces that
> differ only slightly from the background and displays them in black or
> white instead, to keep things readable.  What you see is presumably a
> symptom of this behavior.

I need to make things unreadable because I'm using this code for
presentation. Unnecessary things for presentation should be invisible.

--Kazu

Re: A bug set-face-background

[Kazu Yamamoto]

Hi Aaron,

> I think this is a manifestation of bug 15815.
> 
> http://debbugs.gnu.org/cgi/bugreport.cgi?bug=15815

Oh, thanks. Probably the same problem.

--Kazu

Re: A bug set-face-background

[Jan Djärv]

Hello.

7 nov 2013 kl. 02:18 skrev Kazu Yamamoto (山本和彦) <kazu@iij.ad.jp>:

> Hi Michael,
> 
>> I experience that since some time, Emacs display "overrides" faces that
>> differ only slightly from the background and displays them in black or
>> white instead, to keep things readable.  What you see is presumably a
>> symptom of this behavior.
> 
> I need to make things unreadable because I'm using this code for
> presentation. Unnecessary things for presentation should be invisible.
> 

Use invisible text property?

	Jan D.

Re: A bug set-face-background

[Eli Zaretskii]

> From: Jan Djärv <jan.h.d@swipnet.se>
> Date: Thu, 7 Nov 2013 07:00:43 +0100
> Cc: Michael Heerdegen <michael_heerdegen@web.de>,
> 	"emacs-devel@gnu.org devel" <emacs-devel@gnu.org>
> 
> Hello.
> 
> 7 nov 2013 kl. 02:18 skrev Kazu Yamamoto (山本和彦) <kazu@iij.ad.jp>:
> 
> > Hi Michael,
> > 
> >> I experience that since some time, Emacs display "overrides" faces that
> >> differ only slightly from the background and displays them in black or
> >> white instead, to keep things readable.  What you see is presumably a
> >> symptom of this behavior.
> > 
> > I need to make things unreadable because I'm using this code for
> > presentation. Unnecessary things for presentation should be invisible.
> > 
> 
> Use invisible text property?

I think customizing the corresponding face(s) should also work, no?

Re: A bug set-face-background

[Jan Djärv]

Hello.

7 nov 2013 kl. 16:55 skrev Eli Zaretskii <eliz@gnu.org>:

>> From: Jan Djärv <jan.h.d@swipnet.se>
>> Date: Thu, 7 Nov 2013 07:00:43 +0100
>> Cc: Michael Heerdegen <michael_heerdegen@web.de>,
>> 	"emacs-devel@gnu.org devel" <emacs-devel@gnu.org>
>> 
>> Hello.
>> 
>> 7 nov 2013 kl. 02:18 skrev Kazu Yamamoto (山本和彦) <kazu@iij.ad.jp>:
>> 
>>> Hi Michael,
>>> 
>>>> I experience that since some time, Emacs display "overrides" faces that
>>>> differ only slightly from the background and displays them in black or
>>>> white instead, to keep things readable.  What you see is presumably a
>>>> symptom of this behavior.
>>> 
>>> I need to make things unreadable because I'm using this code for
>>> presentation. Unnecessary things for presentation should be invisible.
>>> 
>> 
>> Use invisible text property?
> 
> I think customizing the corresponding face(s) should also work, no?

Well, yes there is a bug here.  But I was thinking of marking text that has foreground == background.  The region face may have distant-foreground, and thus it becomes visible.
Come to think of it, marking such text would make it visible anyway if region face only defines background.  So text is not properly hidden IMHO.

	Jan D.