set_baseline_position
Description:
Sets the baseline position of a box layout.
The baseline position affects only horizontal boxes with at least one baseline aligned child. If there is more vertical space available than
requested, and the baseline is not allocated by the parent then the given position is used to allocate the baseline within the
extra space available.
Parameters:
| this |
a `GtkBoxLayout` |
| position |
a `GtkBaselinePosition` |