NS font case sensitivity

NS font case sensitivity

[Jason Rumney]

I just now came across this snippet in font.c:


      Lisp_Object alters
    = Fassoc_string (val, Vface_alternative_font_family_alist,
#ifndef HAVE_NS
             Qt
#else
             Qnil
#endif
             );


Is there a good reason why the entries in 
face-alternative-font-family-alist need to be case sensitive on NS when 
they are not on other platforms?

Re: NS font case sensitivity

[Glenn Morris]

For reference, this is bug #2526.

Re: NS font case sensitivity

[Adrian Robert]

Jason Rumney <jasonr <at> gnu.org> writes:

> Is there a good reason why the entries in 
> face-alternative-font-family-alist need to be case sensitive
> on NS when they are not on other platforms?

Font family matching is case sensitive in the API used
by the NS font driver.

Re: NS font case sensitivity

[Jason Rumney]

Adrian Robert wrote:
> Jason Rumney <jasonr <at> gnu.org> writes:
>
>   
>> Is there a good reason why the entries in 
>> face-alternative-font-family-alist need to be case sensitive
>> on NS when they are not on other platforms?
>>     
>
> Font family matching is case sensitive in the API used
> by the NS font driver.
>   

I'm not sure that is relevant here. This variable (actually it is 
exposed to lisp as face-font-family-alternatives) is only used when it 
has already been determined that the named font does not exist in the 
system, so for example on other platforms if some lisp code requests the 
font "Sans Serif" or "sans serif" and a font by that name is not 
defined, "helv", "helvetica", "arial" and "fixed" are tried as 
alternatives. But on NS, that list will only be used if the lisp code 
requests that font with matching case.

Re: NS font case sensitivity

[Adrian Robert]

On Jun 19, 2009, at 8:24 AM, Jason Rumney wrote:

> Adrian Robert wrote:
>> Jason Rumney <jasonr <at> gnu.org> writes:
>>
>>
>>> Is there a good reason why the entries in face-alternative-font- 
>>> family-alist need to be case sensitive
>>> on NS when they are not on other platforms?
>>>
>>
>> Font family matching is case sensitive in the API used
>> by the NS font driver.
>>
>
> I'm not sure that is relevant here. This variable (actually it is  
> exposed to lisp as face-font-family-alternatives) is only used when  
> it has already been determined that the named font does not exist  
> in the system, so for example on other platforms if some lisp code  
> requests the font "Sans Serif" or "sans serif" and a font by that  
> name is not defined, "helv", "helvetica", "arial" and "fixed" are  
> tried as alternatives. But on NS, that list will only be used if  
> the lisp code requests that font with matching case.

Logically, this behavior is consistent with family names being case  
sensitive -- the user customizing face-font-family-alternatives may  
want to specify different alternative lists for different family  
names, even if they differ only in their case.  But practically, I  
doubt the situation will come up in that way -- so we might as well  
remove the ifdef to streamline the code if that is best.