Re: placement of clef before break

[Malte Meyn]

Am 08.03.2017 um 08:43 schrieb Juan Cristóbal Cerrillo:
> In the following example, I would like to be able to place the clef after the 
> repeat barline, and the time signature in parenthesis.

Time signature in parentheses: http://lsr.di.unimi.it/LSR/Item?id=734

For the order of Grobs at the line break there is
BreakAlignment.break-align-orders, it’s three lists (or vectors?) of
symbols you can override:

\once \override Score.BreakAlignment.break-align-orders =
    ##(
       ;; end of line
       (left-edge cue-end-clef ambitus breathing-sign
         cue-clef staff-bar clef
         key-cancellation key-signature time-signature custos)
       ;; unbroken
       (left-edge cue-end-clef ambitus breathing-sign
         clef cue-clef staff-bar
         key-cancellation key-signature time-signature custos)
       ;; begin of line
       (left-edge ambitus breathing-sign clef
         key-cancellation key-signature time-signature staff-bar
cue-clef custos))

I took the original list from scm/define-grobs.scm and moved the “clef”
entry in the first sublist to behind staff-bar.

In your case you don’t really need the complete list for a \once
\override because you don’t have ambitus, breathing-sign, key-signature
etc. So the following is sufficient:

    \once \override Score.BreakAlignment.break-align-orders =
    ##((left-edge staff-bar clef time-signature)
       ()
       (left-edge clef time-signature))

I don’t know why (bug?) but the clef before the break isn’t really
nicely positioned so one has to override X-offset to correct this:

    \once \override Staff.Clef.before-line-breaking =
    #(lambda (grob)
       (if (and (ly:item? grob)
                (equal? (ly:item-break-dir grob) LEFT))
             (ly:grob-set-property! grob 'X-offset 1)))

(I used before-line-breaking here because the override shall only move
the clef before the break.)