### 3.2.110 staff-symbol-interface

This spanner draws the lines of a staff. A staff symbol defines a vertical unit, the staff space. Quantities that go by a half staff space are called positions. The center (i.e., middle line or space) is position 0. The length of the symbol may be set by hand through the `width` property.

#### User settable properties:

> `ledger-extra` (dimension, in staff space)

>   Extra distance from staff line to draw ledger lines for.

> `ledger-line-thickness` (pair of numbers)

>   The thickness of ledger lines. It is the sum of 2 numbers: The first is the factor for line thickness, and the second for staff space. Both contributions are added.

> `ledger-positions` (list)

>   Repeating pattern for the vertical positions of ledger lines. Bracketed groups are always shown together.

> `line-count` (integer)

>   The number of staff lines.

> `line-positions` (list)

>   Vertical positions of staff lines.

> `staff-space` (dimension, in staff space)

>   Amount of space between staff lines, expressed in global `staff-space`.

> `thickness` (number)

>   Line thickness, generally measured in `line-thickness`.

> `width` (dimension, in staff space)

>   The width of a grob measured in staff space.

This grob interface is used in the following graphical object(s): StaffSymbol.

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