Adds a new Widget to this Container.
If this Container is ContainerType.SINGLE and already has a child widget, that widget will be removed and replaced by the new widget.
If this container is ContainerType.MULTIPLE, the new widget will be added to the end of the list of children.
If the widget being added is already contained in another Container, it will be removed from that container before it is added to this one.
Window widgets cannot be children.
widget |
The Widget to add to this container. |