public class Viewport : Widget, Accessible, Buildable, ConstraintTarget, Scrollable
The Viewport widget acts as an adaptor class, implementing scrollability for child widgets that lack their own scrolling capabilities.
The GtkViewport will start scrolling content only if allocated less than the child widget’s minimum size in a given orientation.
GtkViewport has a single CSS node with name `viewport`.
GtkViewport uses the gtk_accessible_role_group role.