LSR/1098
< LSR
Indenting individual systems
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Beschreibung
LilyPond scores are indented rather like text paragraphs: all lines except the first are indented by the same amount (short-indent). This layout constraint is applied in advance and cannot be modified later e.g. on a line-by-line basis.
LilyPond users who need a differently indented line can arrange for that line to start a new score, as in LSR 966. That may be a reasonable workaround at a more or less natural break such as a coda, but in general the structure clash introduces severe fragmentation requiring compensatory splicing and fudging.
This snippet demonstrates the pseudoIndent workaround which superimposes an additional line-wise indentation on the score's unmodified layout indentation. This approach avoids all those score change problems.
There are independent parameters for left and right indentations. It also comes with a freebie parameter for succinct instrument-name modding.
Caveats:
- The indenting mechanism is based on an arcane misuse of LeftEdge and may therefore become temporarily or permanently broken through side-effects of developments in the Lilypond code base.
- The code is not protected against multiple calls per system break
%%%%%%%% HEADER %%%%%%%%
%
% this code was prompted by
% https://lists.gnu.org/archive/html/lilypond-user/2019-07/msg00139.html
% and offers a pseudoIndent hack suitable for general use
% keywords:
% indent short-indent indentation system line
% mid-score temporarily arbitrary individual single just only once
% coda margin
% mouse's tale acrostic mesostic spine
%%%%%%%% PSEUDOINDENT FUNCTIONS %%%%%%%%
% these two functions are for indenting individual systems
% - to left-indent a system, apply \pseudoIndent before the music continues
% - \pseudoIndents is similar, but lets you also indent on the right
% - both provide an option for changing that system's instrument names
% N.B. these functions
% - assume application to non-ragged lines (generally the default)
% - include a manual \break to ensure application at line start
% - misbehave if called more than once at the same line start
% the parameters of the (full) pseudoIndents function are:
% 1: name-tweaks
% usually omitted; accepts replacement \markup for instrument names
% as an ordered list; starred elements leave their i-names unchanged.
% 2: left-indent
% additional left-indentation, in staff-space units; can be negative,
% but avoid a total indentation which implies (unsupported) stretching.
% 3: right-indent
% amount of right-indentation, in staff-space units; can be negative.
% - not offered by the (reduced) pseudoIndent function
pseudoIndents = % inline alternative to a new \score, also with right-indent
#(define-music-function (parser location name-tweaks left-indent right-indent)
((markup-list? '()) number? number?)
(define (warn-stretched p1 p2) (ly:input-warning location (_
" pseudoIndents ~s ~s is stretching staff; expect distorted layout") p1 p2))
(let* (
(narrowing (+ left-indent right-indent)) ; of staff implied by args
(set-staffsymbol! (lambda (staffsymbol-grob) ; change staff to new width
(let* (
(left-bound (ly:spanner-bound staffsymbol-grob LEFT))
(left-moment (ly:grob-property left-bound 'when))
(capo? (moment<=? left-moment ZERO-MOMENT)) ; in first system of score
(layout (ly:grob-layout staffsymbol-grob))
(lw (ly:output-def-lookup layout 'line-width)) ; debugging info
(indent (ly:output-def-lookup layout (if capo? 'indent 'short-indent)))
(old-stil (ly:staff-symbol::print staffsymbol-grob))
(staffsymbol-x-ext (ly:stencil-extent old-stil X))
;; >=2.19.16's first system has old-stil already narrowed [2]
;; compensate for this (ie being not pristine) when calculating
;; - old leftmost-x (its value is needed when setting so-called 'width)
;; - the new width and position (via local variable narrowing_)
(ss-t (ly:staff-symbol-line-thickness staffsymbol-grob))
(pristine? (<= 0 (car staffsymbol-x-ext) ss-t)) ; would expect half
(leftmost-x (+ indent (if pristine? 0 narrowing)))
(narrowing_ (if pristine? narrowing 0)) ; uses 0 if already narrowed
(old-width (+ (interval-length staffsymbol-x-ext) ss-t))
(new-width (- old-width narrowing_))
(new-rightmost-x (+ leftmost-x new-width)) ; and set! this immediately
(junk (ly:grob-set-property! staffsymbol-grob 'width new-rightmost-x))
(in-situ-stil (ly:staff-symbol::print staffsymbol-grob))
(new-stil (ly:stencil-translate-axis in-situ-stil narrowing_ X))
;(new-stil (stencil-with-color new-stil red)) ; for when debugging
(new-x-ext (ly:stencil-extent new-stil X)))
(ly:grob-set-property! staffsymbol-grob 'stencil new-stil)
(ly:grob-set-property! staffsymbol-grob 'X-extent new-x-ext)
)))
(set-X-offset! (lambda (margin-grob) ; move grob across to line start
(let* (
(old (ly:grob-property-data margin-grob 'X-offset))
(new (lambda (grob) (+ (if (procedure? old) (old grob) old) narrowing))))
(ly:grob-set-property! margin-grob 'X-offset new))))
(tweak-text! (lambda (i-name-grob mkup) ; tweak both instrumentname texts
(if (and (markup? mkup) (not (string=? (markup->string mkup) "*")))
(begin
(ly:grob-set-property! i-name-grob 'long-text mkup)
(ly:grob-set-property! i-name-grob 'text mkup)
)))) ; else retain existing text
(install-narrowing (lambda (leftedge-grob) ; on staves, + adapt left margin
(define (grob-name x) (assq-ref (ly:grob-property x 'meta) 'name))
(let* (
(sys (ly:grob-system leftedge-grob))
(all-grobs (ly:grob-array->list (ly:grob-object sys 'all-elements)))
(grobs-named (lambda (name)
(filter (lambda (x) (eq? name (grob-name x))) all-grobs)))
(first-leftedge-grob (list-ref (grobs-named 'LeftEdge) 0))
(relsys-x-of (lambda (g) (ly:grob-relative-coordinate g sys X)))
(leftedge-x (relsys-x-of first-leftedge-grob))
(leftedged? (lambda (g) (= (relsys-x-of g) leftedge-x)))
(leftedged-ss (filter leftedged? (grobs-named 'StaffSymbol))))
(if (eq? leftedge-grob first-leftedge-grob) ; ignore other leftedges [1]
(begin
(for-each set-staffsymbol! leftedged-ss)
(for-each set-X-offset! (grobs-named 'SystemStartBar))
(for-each set-X-offset! (grobs-named 'InstrumentName))
(for-each tweak-text! (grobs-named 'InstrumentName) name-tweaks)
))))))
(if (negative? narrowing) (warn-stretched left-indent right-indent))
#{ % and continue anyway
% ensure that these overrides are applied only at begin-of-line
\break % (but this does not exclude unsupported multiple application)
% give the spacing engine notice regarding the loss of width for music
\once \override Score.LeftEdge.X-extent = #(cons narrowing narrowing)
% discard line start region of staff and reassemble left-margin elements
\once \override Score.LeftEdge.after-line-breaking = #install-narrowing
% shift the system to partition the narrowing between left and right
\overrideProperty Score.NonMusicalPaperColumn.line-break-system-details
.X-offset #(- right-indent)
% prevent a leftmost barnumber entering a stretched staff
\once \override Score.BarNumber.horizon-padding = #(max 1 (- 1 narrowing))
#}))
pseudoIndent = % for changing just left-indent
#(define-music-function (parser location name-tweaks left-indent)
((markup-list? '()) number?)
#{
\pseudoIndents $name-tweaks $left-indent 0
#})
% [1] versions <2.19.1 can have end-of-line leftedges too
% - these were eliminated in issue 3761
% [2] versions >=2.19.16: the first system behaves differently from the rest
% - a side effect of issue 660 ?
%%%%%%%% LSR EXAMPLES %%%%%%%%
\paper {
indent = 55
short-indent = 40
system-system-spacing.basic-distance = 10
tagline = ##f
}
m = { f'4 f'4 f'4 f'4 } % one measure
showInfo = #(define-music-function (parser location info) (markup?)
#{
\once \override Score.LeftEdge.break-visibility = #begin-of-line-visible % [1]
\once \override Score.LeftEdge.stencil = #(lambda (grob)
(grob-interpret-markup grob info))
#})
%%%%%%%% BASIC EXAMPLE %%%%%%%%
basic-info-line = \markup \translate #'(0 . -4) % trace short indentation
\with-color #blue \draw-dashed-line #'(0 . -49)
v-gap = \markup \vspace #2.25
basic-info-text = \markup \translate #'(-24 . 5)
\column {
\italic "(indent)"
\v-gap
\italic "(short-indent)"
\v-gap
"\pseudoIndent 22"
\v-gap
"\pseudoIndent 44"
\v-gap
"\pseudoIndents 22 22"
\v-gap
\line { "\pseudoIndents 0 44" \translate #'(53 . 0) \italic
"with ragged-right ##f (default)" }
\v-gap
\line { "\pseudoIndents 0 20" \translate #'(72 . 0) \italic
\right-column { "ragged-last ##f" "(default)" }}}
basic = {
\omit Score.BarNumber
\m \m \m \m \m \m
\break % a short-indented system for reference (also info anchor:)
\showInfo \markup \combine \basic-info-text \basic-info-line
\m \m \m \m \m \m \m
\pseudoIndent 22
\m \m \m \m \m
\pseudoIndent 44
\m \m \m
\pseudoIndents 22 22
\m \m \m
\pseudoIndents 0 44
\m \m \m
\pseudoIndents 0 20
\m \m \m \m \m \bar "|."
}
\markup \huge \bold \column { " " " Basic usage" " "}
\score {
\new Staff { \basic }
\layout {}
}
%%%%%%%% DEMO EXAMPLE %%%%%%%%
demo-info-line = \markup\translate #'(85.3 . 16) % trace right margin
\with-color #blue \draw-dashed-line #'(0 . -56)
demo-info-text = \markup \translate #'(-24 . 13)
\column \italic {
"right-indent at head"
" "
"stop/startStaff OK"
" "
" "
" "
" "
"(short-indent)"
" "
" "
" "
" "
"outdent without stretching"
" "
"name-tweaks displaying"
"how its list is ordered"
" "
" "
\line {"using name-tweaks "
\column \upright { " " "\"\"" "\\mkCoda" * }
" to "
\column{ " " "hide name" "change name" "(leave name as it is)"}}
}
mkCoda = \markup % cf LSR966
\vcenter { \bold "coda" \fontsize #3 \musicglyph #"scripts.coda" }
demo = {
\pseudoIndents 0 22 % no additional left-indenting applied
s1*4
\break % a short-indented system for reference (also info anchor:)
\showInfo \markup \combine \demo-info-text \demo-info-line
s1*7
\pseudoIndents \markuplist { 1 2 3 } 11 -4 % display the i-name ordering
s1*6
\pseudoIndent \markuplist { "" * \mkCoda } 55 % hide 1; leave 2; change 3
s1*2 \bar "|."
}
demoHi = {
\m \m \m \m
\m \m \m \m \m \m \m
\m \m \m \m \m \m
\m \m
}
demoLo = {
\m \m \stopStaff s1 \startStaff \m
\m \m \m \m \m \m \m
\m \m \m \m \m \m
\m \m
}
\markup \huge \bold \column { " " " Further possibilities" " "}
\score {
\new StaffGroup
\with { instrumentName = "SYS" shortInstrumentName = "sys" }
<<
\new Staff
\with { instrumentName = "HI" shortInstrumentName = "hi" }
<< \demo \demoHi >>
\new RhythmicStaff
\with { instrumentName = "LO" shortInstrumentName = "lo" }
{ \demoLo }
>>
\layout {
\override Score.InstrumentName.self-alignment-X = #RIGHT
\override Score.InstrumentName.padding = 2
}
}
%%%%%%%% END %%%%%%%