Mapping and unmapping widgets

A widget that is managed but not mapped still participates in geometry management, that is, it takes up space in its parent, but it is not actually drawn. Normally this results in a blank area in the parent where the widget would otherwise appear.

In the following example, assume that the widget tree is created, managed and realized, but the second CwLabel is subsequently unmapped. Notice that the label is removed from the screen, but its parent still reserves its position in the row-column widget.