LilyPond program-reference: 3.1.11 BarLine

### 3.1.11 BarLine

BarLine objects are created by: Bar_engraver.

Standard settings:

> `break-align-symbol` (symbol):

>   `'staff-bar`

>   This key is used for aligning and spacing breakable items.

> `break-align-anchor` (number):

>   `ly:bar-line::calc-anchor`

>   Grobs aligned to this break-align grob 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.

> `glyph` (string):

>   `"|"`

>   A string determining what ‘style’ of glyph is typeset. Valid choices depend on the function that is reading this property.

> `gap` (dimension, in staff space):

>   `0.4`

>   Size of a gap in a variable symbol.

> `layer` (integer):

>   `0`

>   The output layer (a value between 0 and 2): Layers define the order of printing objects. Objects in lower layers are overprinted by objects in higher layers.

> `break-visibility` (vector):

>   `bar-line::calc-break-visibility`

>   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`.

> `stencil` (unknown):

>   `ly:bar-line::print`

>   The symbol to print.

> `bar-size` (dimension, in staff space):

>   `ly:bar-line::calc-bar-size`

>   The size of a bar line.

> `allow-span-bar` (boolean):

>   `#t`

>   If false, no inter-staff bar line will be created below this bar line.

> `space-alist` (list):

>   `'((time-signature extra-space . 0.75) (custos minimum-space . 2.0) (clef minimum-space . 1.0) (key-signature extra-space . 1.0) (key-cancellation extra-space . 1.0) (first-note fixed-space . 1.3) (next-note semi-fixed-space . 0.9) (right-edge extra-space . 0.0))`

>   A table that specifies distances between prefatory items, like clef and time-signature. The format is an alist of spacing tuples: `(break-align-symbol type . distance)`, where type can be the symbols `minimum-space` or `extra-space`.

> `kern` (dimension, in staff space):

>   `3.0`

>   Amount of extra white space to add. For bar lines, this is the amount of space after a thick line.

> `thin-kern` (number):

>   `3.0`

>   The space after a hair-line in a bar line.

> `hair-thickness` (number):

>   `1.9`

>   Thickness of the thin line in a bar line.

> `thick-thickness` (number):

>   `6.0`

>   Bar line thickness, measured in `line-thickness`.

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

#### Internals Reference