If true, the topCenter will always appear on a separate line by itself, otherwise the
topCenter will appear in the top row if there is room and will be moved to the second row if
required.
This Thread will exit Geeboss in a clean way in case the virtual machine is
terminated in response to a user interrupt, such as typing ^C, or a system-wide event,
such as user logoff or system shutdown.
Instances of this class implement a Composite that lays out three children horizontally and
allows programmatic control of layout and border parameters.