[NTG-context] Re: Use headcommand in \definedescription together with \definehighlight (now: \definestartstop)

27 Jun 2024

      Gerion Entrup schrieb am 25.06.2024 um 08:41:
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Am Dienstag, 25. Juni 2024, 00:09:09 MESZ schrieb Wolfgang Schuster:
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Gerion Entrup schrieb am 24.06.2024 um 23:57:
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Am Montag, 24. Juni 2024, 21:20:19 MESZ schrieb Aditya Mahajan:
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On Mon, 24 Jun 2024, Gerion Entrup wrote:
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Hi,
I was in the process to convert an itemize part to a description and wanted to simplify the code in the same move.
I discovered headcommand for that, but struggled to set the text in an highlight _and_ make a colon at the end.
Not sure what exactly you want, but how about:
\definehighlight[hl][style={\m{>}\,\switchtobodyfont[tt]}]
% This is the wrong way to define such a command as '>' is not part of the style. I have left this definition just for comparison with the soln below.
Is there a better way to define a highlight that sets a style (color, font) _and_ a prefix (symbol)?
Another way, I know of, would be just a plain def, something like \def{\hl}{\groupedcommand{>\,\switchtobodyfont[tt]}{}}, but actually I want to define a highlight (just with an additional prefix).
1. ConTeXt already uses \hl as name for a existing command.
2. Use \definestartstop:
\definestartstop [gerion] [style=mono,left={›\thinspace}]
\starttext
text
\gerion{text}
\stoptext
...
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\definedescription[category][
  alternative=top,
  headstyle=bold,
  width=broad,
]
\definedescription[desc][
  width=fit,
  distance={\widthofstring{~}},
distance=\spaceamount,
Wolfgang
This seems to be much better but does not lead to the wanted result. The full example now is:
```
\definestartstop[myhl][style=mono,left={›\thinspace}]
\definedescription[categorie][
  alternative=top,
  headstyle=bold,
  width=broad,
]
\definedescription[desc][
  width=broad,
  distance=\spaceamount,
  headcommand={\groupedcommand{\startmyhl}{\stopmyhl :}},
  headstyle=,
  before={\startpacked},
  after={\stoppacked},
  alternative=hanging
]
\starttext
This is a \myhl{highlight}.
Some listings
\startcategorie{Itemize}
  \startitemize[packed]
      \item \myhl{first}: one
      \item \myhl{second}: two
  \stopitemize
\stopcategorie
Now the same as desc:
\startcategorie{Desc}
  \startdesc{first} one \stopdesc
  \startdesc{second} two \stopdesc
\stopcategorie
\stoptext
```
This adopts the correct style in \startdesc \stopdesc and sets the colon but omits the › (the left part).
You can do the following in the next version.

1. Add "arguments=yes" to \definestartstop to enable the optional 
argument for the new command.

2. Use the new commands with the "headcommand" key and apply ":" as 
right delimiter for the content of \Highlight.

\definestartstop
   [Highlight]
   [arguments=yes,
        style=mono,
         left={›\thinspace}]

\definedescription
   [description]
   [      width=broad,
       distance=\spaceamount,
    headcommand=\Highlight[right=:],
    alternative=hanging]

\starttext

This is a \Highlight{highlight}.

\startdescription[title={Lorem ipsum}]
\samplefile{lorem}
\stopdescription

\stoptext

Wolfgang