Re: Numbers as easy note heads with RhythmicStaff

[Aaron Hill]

On 2018-06-15 05:27, Gianmaria Lari wrote:
> \version "2.19.81"
> #(define Ez_numbers_engraver
>    (make-engraver
>     (acknowledgers
>      ((note-head-interface engraver grob source-engraver)
>       (let* ((context (ly:translator-context engraver))
>      (tonic-pitch (ly:context-property context 'tonic))
>      (tonic-name (ly:pitch-notename tonic-pitch))
>      (grob-pitch
>       (ly:event-property (event-cause grob) 'pitch))
>      (grob-name (ly:pitch-notename grob-pitch))
>      (delta (modulo (- grob-name tonic-name) 7))
>      (note-names
>       (make-vector 7 (number->string (1+ delta)))))
> (ly:grob-set-property! grob 'note-names note-names))))))
>
> \layout {
>   ragged-right = ##t
>   \context {
>     \Voice
>     \consists \Ez_numbers_engraver
>   }
> }
>
> \new RhythmicStaff { a4 b8 a }
>
> and this is the error I get
>
> Interpreting music..document.ly:8:26 <0>: In procedure 
> ly:pitch-notename in
> expression (ly:pitch-notename tonic-pitch):
>
> ..document.ly:8:26 <1>: Wrong type argument in position 1 (expecting
> Pitch): ()
>
>
> Any suggestion to fix it?

It appears that RhythmicStaves do not have a tonic property.  So there 
is no reference from which you can derive the numbering.  You can 
explicitly specify a tonic:

%%%%
  \new RhythmicStaff \with { tonic = #(ly:make-pitch 0 0 0) }
    { \easyHeadsOn a4 b8 a }
%%%%

-- Aaron Hill