window-current-scroll-bars

window-current-scroll-bars is a compiled Lisp function in `window.el'.

(window-current-scroll-bars &optional WINDOW)

Return the current scroll bar types for WINDOW.
WINDOW must be a live window and defaults to the selected one.

The return value is a cons cell (VERTICAL . HORIZONTAL) where
VERTICAL specifies the current location of the vertical scroll
bar (`left', `right' or nil), and HORIZONTAL specifies the
current location of the horizontal scroll bar (`bottom' or nil).

Unlike `window-scroll-bars', this function reports the scroll bar
type actually used, once frame defaults and `scroll-bar-mode' are
taken into account.