Gtk.ScrolledWindow::scroll-child

function callback(scrolled_window, scroll:Gtk.ScrollType, horizontal:Boolean, ):Boolean;

The ::scroll-child signal is a <link linkend="keybinding-signals">keybinding signal</link> which gets emitted when a keybinding that scrolls is pressed. The horizontal or vertical adjustment is updated which triggers a signal that the scrolled windows child may listen to and scroll itself.