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3.1.75 LeftEdge

The left edge of a staff. Useful as an anchor point for other grobs.

LeftEdge objects are created by the following engraver(s): Break_align_engraver.

Standard settings:

break-align-anchor (number):

ly:break-aligned-interface::calc-extent-aligned-anchor

Grobs aligned to this breakable item will have their X-offsets shifted by this number. In bar lines, for example, this is used to position grobs relative to the (visual) center of the bar line.

break-align-symbol (symbol):

'left-edge

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

break-visibility (vector):

#(#f #f #t)

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

non-musical (boolean):

#t

True if the grob belongs to a NonMusicalPaperColumn.

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

'((ambitus extra-space . 1.15)
  (breathing-sign minimum-space . 0.0)
  (cue-end-clef extra-space . 0.8)
  (clef extra-space . 0.8)
  (cue-clef extra-space . 0.8)
  (signum-repetitionis extra-space . 0.0)
  (staff-bar extra-space . 0.0)
  (staff-ellipsis extra-space . 0.0)
  (key-cancellation extra-space . 0.0)
  (key-signature extra-space . 0.8)
  (time-signature extra-space . 1.0)
  (custos extra-space . 0.0)
  (first-note fixed-space . 2.0)
  (right-edge extra-space . 0.0))

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.

X-extent (pair of numbers):

'(0 . 0)

Extent (size) in the X direction, measured in staff-space units, relative to object’s reference point.

Y-extent (pair of numbers):

'(0 . 0)

Extent (size) in the Y direction, measured in staff-space units, relative to object’s reference point.

This object supports the following interface(s): break-aligned-interface, grob-interface and item-interface.

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