When a widget is unmanaged, its parent can reclaim the space the widget occupies. If the parent widget is a composite that performs layout of its children, it will adjust child layout accordingly. A row-column was chosen for this example because it provides a visual demonstration of the difference between mapping and managing widgets.
In this example, assume that the widget tree is created, managed and
realized, but CwLabel 2 is subsequently unmanaged. Not only
is the button removed from the screen, or unmapped, but it also loses its
position in the row-column widget.