This container accepts a single child widget. It adds scrollbars to the child widget and optionally draws a beveled frame around the child widget. The scrolled window can work in two ways: 1) Some widgets have native scrolling support; these widgets handle certain Gtk::Adjustment signals. Widgets with native scroll support include Gtk::TreeView, Gtk::TextView, and Gtk::Layout. 2) For widgets that lack native scrolling support, such as Gtk::Table, Gtk::Box, and so on, the widget will be placed inside a Gtk::Viewport.
The position of the scrollbars is controlled by the scroll adjustments. See Gtk::Adjustment for the fields in an adjustment - for Gtk::Scrollbar, used by Gtk::ScrolledWindow, the "value" field represents the position of the scrollbar, which must be between the "lower" field and "upper - page_size." The "page_size" field represents the size of the visible scrollable area. The "step_increment" and "page_increment" fields are used when the user asks to step down (using the small stepper arrows) or page down (using for example the PageDown key).
If a Gtk::ScrolledWindow doesn't behave quite as you would like, or doesn't have exactly the right layout, it's very possible to set up your own scrolling with Gtk::Scrollbar and, for example, a Gtk::Table.