### 3.1.50 GridLine

GridLine objects are created by: Grid_line_span_engraver.

Standard settings:

> `layer` (integer):

>   `0`

>   An integer which determines the order of printing objects. Objects with the lowest value of layer are drawn first, then objects with progressively higher values are drawn, so objects with higher values overwrite objects with lower values. By default most objects are assigned a layer value of 1.

> `self-alignment-X` (number):

>   `0`

>   Specify alignment of an object. The value `-1` means left aligned, `0` centered, and `1` right-aligned in X direction. Other numerical values may also be specified.

> `stencil` (stencil):

>   `ly:grid-line-interface::print`

>   The symbol to print.

> `X-extent` (pair of numbers):

>   `ly:grid-line-interface::width`

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

> `X-offset` (number):

>   `#<simple-closure (#<primitive-generic +> #<simple-closure (#<primitive-procedure ly:self-alignment-interface::centered-on-x-parent>) > #<simple-closure (#<primitive-procedure ly:self-alignment-interface::x-aligned-on-self>) >) >`

>   The horizontal amount that this object is moved relative to its X-parent.

This object supports the following interface(s): grid-line-interface, grob-interface, item-interface and self-alignment-interface.

#### Internals Reference v2.18.2 (稳定分支).