Access grob name?

[Simon Albrecht]

Hello,

I’ve written a music function which applies some tweaks on dynamics to 
offset them. Unfortunately, it’s not possible to use the offset music 
function on X-offset, because it is a mutable property. Thus I have to 
add a displacement for DynamicText so that it is not aligned to its 
baseline, but to the ‘center’ like normally.
Now, it would help if the music function could find out by itself 
whether to apply this displacement, depending on which grob it is 
applied to. As an example (attached also):
%%%%%%%%%%
\version "2.19.27"

test =
#(define-music-function (ev) (ly:music?)
   (tweak 'color red ev))

{
  c''-\test \> g'-\test \f
}
%%%%%%%%%%
How can I modify the function so that only the DynamicText is colored, 
the Hairpin isn’t?

TIA, Simon

access-grob-name.ly
Description: Text Data