Gtk.ScrolledWindow.prototype.set_policy

function set_policy(hscrollbar_policy:Gtk.PolicyType, vscrollbar_policy:Gtk.PolicyType):void {
    // Gjs wrapper for gtk_scrolled_window_set_policy()
}

Sets the scrollbar policy for the horizontal and vertical scrollbars.

The policy determines when the scrollbar should appear; it is a value from the Gtk.PolicyType enumeration. If Gtk.PolicyType.always, the scrollbar is always present; if Gtk.PolicyType.never, the scrollbar is never present; if Gtk.PolicyType.automatic, the scrollbar is present only if needed (that is, if the slider part of the bar would be smaller than the trough - the display is larger than the page size).