Re: cross-staff versions of \arpeggioArrowUp etc.

[Mark Polesky]

Joe Neeman wrote:

> Have you tried using ly:context-property-where-defined instead of
> searching for PianoStaff explicitly? There are non-PianoStaff contexts
> containing Span_arpeggio_engraver, after all. Other than that, this is a
> very cool trick!

Joe,

Thanks for the tip. I rewrote arpeggio-generic with ly:context-
property-where-defined and also made some changes to arpeggioNormal.

Also, line 281 of property-init.ly says this:

% For drawing vertical chord brackets with \arpeggio
% This is a shorthand for the value of the print-function property 
% of either Staff.Arpeggio or PianoStaff.Arpeggio, depending whether 
% cross-staff brackets are desired. 

This is completely false, right? Otherwise these commands would work
without the \applyContext gymnastics I've been coding in this thread.
If my code (below) gets approved, I think I'll either remove the
comment it or change it to:

% These commands look for 'connectArpeggios (cross-staff arpeggios)
% to determine the proper context in which to operate.

Any objections? How close is this to being acceptable? I'll wait for
approval.

Thanks.
- Mark

*****************
\version "2.13.3"


%%%%%% begin property-init.ly revision %%%%%%


#(define (arpeggio-generic context pushpops)
  (let* ((parent (ly:context-property-where-defined context
                                                    'connectArpeggios))
         (target (if (null? parent) context parent)))
    (for-each
      (lambda (pushpop)
        (if (pair? pushpop)
            (ly:context-pushpop-property target
                                         'Arpeggio
                                         (car pushpop)
                                         (cdr pushpop))
            (ly:context-pushpop-property target
                                         'Arpeggio
                                         pushpop)))
      pushpops)))

arpeggioArrowUp =
\applyContext
  #(lambda (context)
     (arpeggio-generic context
       `(stencil X-extent (arpeggio-direction . ,UP))))

arpeggioArrowDown =
\applyContext
  #(lambda (context)
     (arpeggio-generic context
       `(stencil X-extent (arpeggio-direction . ,DOWN))))

arpeggioNormal =
\applyContext
  #(lambda (context)
    (let ((Staff (ly:context-find context 'Staff)))
      (if (and Staff (not (eq? context Staff)))
          (arpeggio-generic Staff
            `(stencil X-extent arpeggio-direction dash-definition)))
      (arpeggio-generic context
        `(stencil X-extent arpeggio-direction dash-definition))))

arpeggioBracket =
\applyContext
  #(lambda (context)
     (arpeggio-generic context
       `(X-extent (stencil . ,ly:arpeggio::brew-chord-bracket))))


%%%%%% end property-init.ly revision %%%%%%


%%%%%% demonstration %%%%%%


\new PianoStaff \relative <<
  \new Staff {
    \arpeggioArrowUp
    <c e g>4\arpeggio
    \arpeggioNormal
    <c e g>\arpeggio
    \set PianoStaff.connectArpeggios = ##t
    \arpeggioArrowUp
    <c e g>\arpeggio
    \arpeggioBracket
    <c e g>\arpeggio
    \set PianoStaff.connectArpeggios = ##f
    \arpeggioNormal
    <c e g>\arpeggio
  }
  \new Staff {
    \clef bass
    \arpeggioArrowDown
    <c, e g>4\arpeggio
    <c e g>\arpeggio
    <c e g>\arpeggio
    <c e g>\arpeggio
    <c e g>\arpeggio
  }
>>