gtk:viewport-scroll-to (viewport descendant &optional scroll)

viewport -- a gtk:viewport widget
descendant -- a descendant gtk:widget object of the viewport
scroll -- an optional gtk:scroll-info instance, or the default nil value to scroll into view

Scrolls a descendant of the viewport into view. The viewport and the descendant widget must be visible and mapped for this function to work, otherwise no scrolling will be performed.

Since 4.12