By trial-and-error I’ve come up with the following. It seems like a hack but both variants are close enough to my requirements that I would be able to work with one of them.
There’s still one catch: When I change the caption key „location“ to „bottom“ together with „inbetween={\blank[-\strutdepth]}“ the picture is aligned with the black line (top of the first text line).
This would actually be the preferred solution also for „{left,high}“. Yet I couldn’t find a possibility to shift the picture vertically by some millimeters.
Florian.
\useMPlibrary [dum]
\setuplayout [grid=yes]
\setupinterlinespace [line=20pt]
\setupcaption [figure] [
location={left,high},
%% location={bottom}, %different alignment
number=no,
% inbetween={\blank[-.01mm]}, %Variant 1: picture top-aligned, caption on grid
inbetween={\blank[-\strutdepth]}, %Variant 2: picture and caption top-aligned, caption not on grid
]
\starttext
\showgrid
\startplacefigure
[location=top,none,title={There is not so much basic instruction, as of now, as there was
in the old days, showing the differences between good and bad typographic design.},
]
\placeongrid[max]{
\externalfigure [dummy] [width=.6\textwidth]
}
\stopplacefigure
\input zapf
\stoptext