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3.1.40 Custos

A custos, mainly used in older notation like Gregorian chant.

Custos objects are created by the following engraver(s): Custos_engraver.

Standard settings:

break-align-symbol (symbol):

'custos

This key is used for aligning, ordering, and spacing breakable items. See break-alignment-interface.

break-visibility (vector):

#(#t #f #f)

A vector of 3 booleans, #(end-of-line unbroken begin-of-line). #t means visible, #f means killed.

neutral-direction (direction):

-1

Which direction to take in the center of the staff.

no-ledgers (boolean):

#f

If set, don’t draw ledger lines on this object.

non-musical (boolean):

#t

True if the grob belongs to a NonMusicalPaperColumn.

space-alist (alist, with symbols as keys):

'((first-note minimum-fixed-space . 0.0)
  (right-edge extra-space . 0.1))

An alist that specifies distances from this grob to other breakable items, using the format:

'((break-align-symbol . (spacing-style . space))
  (break-align-symbol . (spacing-style . space))
  ...)

Standard choices for break-align-symbol are listed in break-alignment-interface. Additionally, three special break-align symbols available to space-alist are:

first-note

used when the grob is just left of the first note on a line

next-note

used when the grob is just left of any other note; if not set, the value of first-note gets used

right-edge

used when the grob is the last item on the line (only compatible with the extra-space spacing style)

If space-alist is defined for a grob that gets spaced in a staff, an entry for first-note must be present. If there is no next-note entry, the value of first-note is used instead.

Choices for spacing-style are:

extra-space

Put this much space between the two grobs. The space is stretchable and shrinkable when paired with first-note or next-note; otherwise it is fixed.

minimum-space

Put at least this much space between the left sides of both grobs, without allowing them to collide. The space is stretchable and shrinkable when paired with first-note or next-note; otherwise it is fixed. Not compatible with right-edge.

fixed-space

Only compatible with first-note and next-note. Put this much fixed space between the grob and the note.

minimum-fixed-space

Only compatible with first-note and next-note. Put at least this much fixed space between the left side of the grob and the left side of the note, without allowing them to collide.

semi-fixed-space

Only compatible with first-note and next-note. Put this much space between the grob and the note, such that half of the space is fixed and half is stretchable and shrinkable.

shrink-space

Only compatible with first-note and next-note. Put this much space between the two grobs. The space is only shrinkable.

semi-shrink-space

Only compatible with first-note and next-note. Put this much space between the grob and the note, such that half of the space is fixed and half is shrinkable.

Rules for this spacing are much more complicated than this. See [Wanske] page 126–134, [Ross] page 143–147.

stencil (stencil):

custos::print

The symbol to print.

style (symbol):

'vaticana

This setting determines in what style a grob is typeset. Valid choices depend on the stencil callback reading this property.

Y-offset (number):

#<unpure-pure-container ly:staff-symbol-referencer::callback >

The vertical amount that this object is moved relative to its Y-parent.

Note that many objects have special positioning considerations, which cause any setting of Y-offset to be ignored or modified, even though the object supports the self-alignment-interface.

Remarks:

• The ledger-positions property holds positions that are taken as-is. Ledger lines may be placed on staff lines. If ledger-positions is not set for this grob but for NoteHead, use the latter one. If this isn’t set either, use either the value set via StaffSymbol or fall back to the standard value.

This object supports the following interface(s): break-aligned-interface, custos-interface, font-interface, grob-interface, item-interface, ledgered-grob-interface and staff-symbol-referencer-interface.

This object is of class Item (characterized by item-interface).