vertical ordering of a custom event-function markup

[Urs Liska]

Hi,

I have a custom \path markup, implemented as an event function.

This works well, but when I add a slur I don't manage to get it to 
behave it properly. What I want is to print the vertical lines and then 
outside the slur, just like with the staccatissimo. But there will first 
be the slur and then the "articulation". So far I haven't found out how 
to manage that. avoid-slur doesn't seem to have any effect, and when I 
override outside-staff-priority I only get to a point where the two 
lines are incorrectly aligned vertically.

Any suggestions how I can print these lines like an ordinary articulation?

Thanks
Urs

%%%

\version "2.19.82"

indicator =
#(define-event-function ()()
   #{
     \tweak X-offset 0.75
     -\markup \path #0.17 #'((moveto 0 0) (lineto 0 0.75))
   #})

\relative {
  %\override TextScript.avoid-slur = #'inside
  d''4 e8 [ ^\indicator ( e ] ^\indicator )
  d8 [ -. ( d ] -. )
}

%%%