\version "2.25.10"
\header {
tagline = ##f
}
\layout {
\context {
\Staff
\accepts ExtraClefStaff
}
\context {
\name ExtraClefStaff
\type Engraver_group
\alias Staff
\accepts Voice
\consists Clef_engraver
\override Clef.font-size = #-4
%% The break-align-symbol stacks the extra clef to the right of
%% the normal clef
\override Clef.break-align-symbol = #'cue-clef
%% This break-visibility repeats the extra clef every bar. Should
%% this be the actual default? Or should the default just be
%% the normal #begin-of-line-visible ?
\override Clef.break-visibility = #end-of-line-invisible
%% different size for first clef in line is uncalled for
firstClef = ##f
}
}
\midi {
\context {
\Staff
\accepts ExtraClefStaff
}
\context {
\name ExtraClefStaff
\type Performer_group
\alias Staff
\accepts Voice
}
}
extraClef =
#(define-music-function (offset clef-type) ((number?) string?)
#{ \new ExtraClefStaff = "extraclef" { }
\change Staff = "extraclef"
#(if offset #{ \override Staff.Clef.Y-offset = #offset #})
\clef #clef-type
#})
all-clef-properties =
#(map (lambda (x) (ly:music-property x 'symbol))
(extract-named-music (make-clef-set "treble_(8)") 'PropertySet))
extraClefEnd =
#(context-spec-music
(make-apply-context
(lambda (ctx)
;; Should be a given in context-spec-music
(if (eq? (ly:context-name ctx) 'ExtraClefStaff)
(begin
;; revert clef-specific settings in case some clef is still
;; issued before the context dies: in that case it should
;; correspond to the supervening Staff clef.
(for-each (lambda (p) (ly:context-unset-property ctx p))
all-clef-properties)
;; All children of the ExtraClefStaff are reseated to its
;; parent context, removing it from the hierarchy
(let ((switch (ly:make-stream-event
(ly:make-event-class 'ChangeParent)
`((context . ,(ly:context-parent ctx))))))
(for-each
(lambda (x)
(ly:broadcast (ly:context-event-source x) switch))
(ly:context-children ctx))))
(ly:programming-error "Not in ExtraClefStaff"))))
'ExtraClefStaff)
\score {
\new Staff = "lower" {
\key d \minor
\numericTimeSignature
\time 3/4
\clef bass
\relative c' {
\voices 1,""
<<
{
s2. r4 r8. \clef treble
\tuplet 3/2 16 { g'32 (a bes }
c8.) c16--
c16-- bes g a
g8.
\omit TupletBracket
\tuplet 3/2 16 { f32 (g a }
bes8.) bes16
} \\
{
d,,,8.-- d16-- d2--~ 2.~
\extraClef #-3 "bass"
\voiceTwo
2.~ \break 2.~2.
\oneVoice
\extraClefEnd
c''2.
}
>>
}
}
}
If made built-in, it would affect several files and introduce a new
default context type.
I don't think it covers multiple simultanous main clefs (like sometimes
seen in compact mensural notation). I am not sure that there'd be a
sensible common interface including this use case.
--
David Kastrup
