Measure width adaptation to tempo indications centered above MMR

[Xavier Scheuer]

Hello,

I seems quite common, in parts with a lot of multi-measure rests, to
print the tempo indications *centered* above the multi-measure rest
(i.e. in the middle of the measure).

However I do not find a clean way with LilyPond to have the measure
width to adapt to the text length.  Would you recommend me to use
MetronomeMark, MultiMeasureRestText or TextScript?

In the doc, NR 1.2.2 Writing rests > Full measure rests, one can find
a snippet called "Multi-measure rest markup" that uses TextScript
attached to "zero-duration" spacer rests.
http://lilypond.org/doc/v2.15/Documentation/notation/writing-rests.html#full-measure-rests
This leads indeed to the best output result but I find this method
really tricky and not convenient at all!

On the LSR one can find snippet #659 : "Forcing measure width to adapt
to MetronomeMark's width".   http://lsr.dsi.unimi.it/LSR/Item?id=659
The idea is more elegant but the result is not centered with 2.15.11.
Why?  And would it be possible to have it centered?

And finally, why can't we use something simple based on
MultiMeasureRestText?  For instance:
  \override MultiMeasureRestText #'extra-spacing-width = #'(0 . 0)
(which does not seem to work, it does not affect the spacing !!
and the text is not *centered* above the multi-measure rest).

Ideas welcome!

Cheers,
Xavier

-- 
Xavier Scheuer <address@hidden>