Sets a boolean value indicating whether a plus (+) or minus (-) button, which allows the user to expand or collapse a node by clicking, appears next to tree nodes that have children.
public void setShowPlusMinus( boolean value )
value
Set to true if a plus or minus button appears next to tree nodes that have children; otherwise, set to false. The default value is true. The plus and minus buttons appear next to root nodes only if the showRootLines property is set to true.
See Also getShowPlusMinus