ButtonAreaLayout
behaves in a similar manner to
FlowLayout
. It lays out all components from left to
right. If
syncAllWidths
is true, the widths of each
component will be set to the largest preferred size width.
This inner class is marked "public" due to a compiler bug.
This class should be treated as a "protected" inner class.
Instantiate it only within subclasses of BasicOptionPaneUI.