The VerticalGlue layout element adds flexible spacing in its location in a BoxColumn of a box layout.

When a column is initially sized, any extra space not consumed by the visible elements is equally distributed to all VerticalGlue elements in that column. This includes any VerticalGlue elements that are implicitly defined through the valign argument for the BoxColumn or the elements of the BoxColumn.

When the row is resized (for example, by resizing the window) the change height of the BoxColumn is applied to the VerticalGlue elements equally when possible.

The VerticalGlue layout element takes no additional options.

A VerticalGlue element can only be contained in a BoxColumn element, and is most useful when the BoxColumn has been specified with valign=none, allowing greater control of spacing of the elements within the column.