paper-column-interface

Paper_column objects form the top-most X-parents for items. The are two types of columns: musical columns, where are attached to, and non-musical columns, where bar-lines, clefs etc. are attached to. The spacing engine determines the X-positions of these objects.

They are numbered, the first (leftmost) is column 0. Numbering happens before line-breaking, and columns are not renumbered after line breaking. Since many columns go unused, you should only use the rank field to get ordering information. Two adjacent columns may have non-adjacent numbers.

User settable properties:

between-cols (pair)

Where to attach a loose column to

line-break-penalty (number)

Penalty for a line break at this column. This affects the choices of the line breaker; it will avoid a line break at a column with a positive penalty and prefer a line break at a column with a negative penalty.

line-break-permission (symbol)

Instructs the line breaker on whether to put a line break at this column. Can be 'force, or 'allow.

line-break-system-details (list)

Alist of properties to use when this column is the start of a system.

page-break-penalty (number)

Penalty for page break at this column. This affects the choices of the page breaker; it will avoid a page break at a column with a positive penalty and prefer a page break at a column with a negative penalty.

page-break-permission (symbol)

Instructs the page breaker on whether to put a page break at this column. Can be 'force, or 'allow.

page-turn-penalty (number)

Penalty for a page turn at this column. This affects the choices of the page breaker; it will avoid a page turn at a column with a positive penalty and prefer a page turn at a column with a negative penalty.

page-turn-permission (symbol)

Instructs the page breaker on whether to put a page turn at this column. Can be 'force, or 'allow.

rhythmic-location (rhythmic location)

Where (bar number, measure position) in the score.

shortest-playing-duration (moment)

The duration of the shortest playing here.

shortest-starter-duration (moment)

The duration of the shortest note that starts here.

used (boolean)

If set, this spacing column is kept in the spacing problem

when (moment)

Global time step associated with this column happen?

Internal properties:

bounded-by-me (unknown)

list of spanners that have this column as start/begin point. Only columns that have grobs or act as bounds are spaced.

grace-spacing (layout object)

a run of grace notes.

spacing (layout object)

the spacing spanner governing this section.

This grob interface is used in the following graphical objects: NonMusicalPaperColumn and PaperColumn