### 3.1.104 StaffGrouper

StaffGrouper objects are not created by any engraver.

Standard settings:

> `staff-staff-spacing` (list):

>   `'((basic-distance . 9) (minimum-distance . 7) (padding . 1) (stretchability . 5))`

>   When applied to a staff-group’s `StaffGrouper` grob, this spacing alist controls the distance between consecutive staves within the staff-group. When applied to a staff’s `VerticalAxisGroup` grob, it controls the distance between the staff and the nearest staff below it in the same system, replacing any settings inherited from the `StaffGrouper` grob of the containing staff-group, if there is one. This property remains in effect even when non-staff lines appear between staves. The alist can contain the following keys:

>   - `basic-distance` – the vertical distance, measured in staff-spaces, between the reference points of the two items when no collisions would result, and no stretching or compressing is in effect.
>   - `minimum-distance` – the smallest allowable vertical distance, measured in staff-spaces, between the reference points of the two items, when compressing is in effect.
>   - `padding` – the minimum required amount of unobstructed vertical whitespace between the bounding boxes (or skylines) of the two items, measured in staff-spaces.
>   - `stretchability` – a unitless measure of the dimension’s relative propensity to stretch. If zero, the distance will not stretch (unless collisions would result).
> `staffgroup-staff-spacing` (list):

>   `'((basic-distance . 10.5) (minimum-distance . 8) (padding . 1) (stretchability . 9))`

>   The spacing alist controlling the distance between the last staff of the current staff-group and the staff just below it in the same system, even if one or more non-staff lines exist between the two staves. If the `staff-staff-spacing` property of the staff’s `VerticalAxisGroup` grob is set, that is used instead. See `staff-staff-spacing` for a description of the alist structure.

This object supports the following interface(s): grob-interface, spanner-interface and staff-grouper-interface.

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