[NTG-context] Odd Font Behavior in startstop Group

[Wolfgang Schuster]

Michael Urban via ntg-context schrieb am 05.02.2022 um 20:28:
> I am experiencing an odd behavior switching text styles in a defined startstop group ("blockquote").   I get different behavior depending on whether the switchtobodyfont in the startstop definition includes the dummy {\it } and {\bf } text.   If they are not there, the italic and boldface switches in the second blockquote revert to the gyreschola body font of the main text; but this only happens if there is an earlier blockquote with no style changes.  This is with:
>
> [...]
>
> Do I need a newer version of ConTeXt, or am I doing something wrong?
> Fonts in ConTeXt are always perilous, alas.  For me, anyway.
>
>
> \definefallbackfamily[story][serif][notoserif][range={greekandcoptic,greekextended},force=yes]
> \definefontfamily[story][serif][TeX Gyre Schola]

The following two font settings are wrong, you're passing the name of a 
typescript for the third argument while \definefontfamily expects the 
family name of a font.

Even though the usage of the command is wrong you didn't notice it 
because as a fallback \definefontfamily uses the Latin Modern version of 
the requested style when no font was found.

> \definefontfamily[story][sans][modern]
> \definefontfamily[story][mono][modern]

The correct settings for both settings are

     \definefontfamily [story] [sans] [Latin Modern Sans]
     \definefontfamily [story] [mono] [Latin Modern Mono] [features=none]

with the "features=none" for the mono font to ensure no ligatures are 
formed.

An alternative for \definefontfamily is to use \definetypeface and 
choose a predefined typescript for the Latin Modern family. You can 
either use

     \definetypeface [story] [ss] [sans] [modern] [default]
     \definetypeface [story] [ss] [mono] [modern] [default]

which uses the 10pt optical size even for smaller and bigger sizes or 
you enable optical sizes with the following typescript

     \definetypeface [story] [ss] [sans] [modern-designsize] [default]
     \definetypeface [story] [ss] [mono] [modern-designsize] [default]


> \definefontfamily[story][mm][TeX Gyre Pagella Math]

I recommend to load the math font with the provided typescript because 
they ensure existing patches (e.g. spacing corrections) for the selected 
font are applied.

     \definetypeface [story] [mm] [math] [pagella] [default]

> \setupbodyfont[story,11pt]
>
> \definestartstop[blockquote]
>   [
>    before={ \blank \startnarrower \setupwhitespace[2pt] \setupindenting[none]
>             \switchtobodyfont[termes]{\it }{\bf }% This is so weird.  Put a comment marker after [termes] for a different result
>    },
>    after={ \stopnarrower \blank \indenting[next]},
>   ]%

ConTeXt already provides a blockquote-environment which can be 
configured to have the same style as your custom environment.

\startsetups [blockquote:style]
     \switchtobodyfont[termes]
     \setupwhitespace[2pt]
\stopsetups

\setupdelimitedtext
   [blockquote]
   [spacebefore=big,
          style=\directsetup{blockquote:style},
      indenting=none,
     indentnext=yes]

Wolfgang