See Also: Requisition Members
How a widget determines its desired size depends on the widget. A Gtk.Label, for example, requests enough space to display all its text. Container widgets generally base their size request on the requisitions of their children.
The size requisition phase of the widget layout process operates top-down. It starts at a top-level widget, typically a Gtk.Window. The top-level widget asks its child for its size requisition by calling Widget.SizeRequest. To determine its requisition, the child asks its own children for their requisitions and so on. Finally, the top-level widget will get a requisition back from its child.