ConTeXt and Metafun: Using environment variables inside overlay

Question

I would like to draw a custom frame for the framed environment using Metafun. I am currently hard-coding the frame color within the Metafun definition. However, I would like the Metafun frame to reference the framecolor option of the framed environment and change color accordingly. This is what I have so far with hard-coded color options:

\startuniqueMPgraphic{box}
path p;
p := unitcircle xscaled \overlaywidth yscaled \overlayheight;

fill p withcolor .85white;
draw p withpen pencircle scaled 2pt withcolor .625red;
\stopuniqueMPgraphic

\defineoverlay[box][\uniqueMPgraphic{box}]

\starttext

\framed[framecolor=blue, background=box]{test}

\stoptext

Does the Metafun definition have access to framed options or is there another way to do this?

score 4 · Accepted Answer · answered Jun 11 '18 at 20:14

4

You can use \framedparameter{framecolor} to access the parameter. This results in an error if framecolor is not set. You can use \MPcolor with \framedparameter to fix that. Example:

\startuniqueMPgraphic{box}
  path p;
  p := unitcircle xscaled \overlaywidth yscaled \overlayheight;

  fill p withcolor .85white;
  draw p withpen pencircle scaled 2pt withcolor \MPcolor{\framedparameter{framecolor}};
\stopuniqueMPgraphic

\defineoverlay
  [box]
  [\uniqueMPgraphic{box}]

\starttext
  \framed[framecolor=blue, background=box]{test}
  \framed[background=box]{foobar}
\stoptext

answered Jun 11 '18 at 20:14

Marco

26,055

Thanks! To get a better understanding of the solution, is the \[environment]parameter type command general? Could I use something similar in contexts outside of just framed? – ssokolen Jun 11 '18 at 20:20
1

Yes, it's a general command. Also see ConTeXt: How do you create your own commands? This doesn't mean it works for every command. Only the ones that actually use the mentioned mechanisms. – Marco Jun 11 '18 at 20:33
3

@Marco You can also use the OverlayLineColor variable to access the framecolor value. This variable and many others are listed in the MetaFun manual. – Wolfgang Schuster Jun 11 '18 at 20:43

ConTeXt and Metafun: Using environment variables inside overlay

1 Answers1