protected final void fireVetoableChange ( String propertyName , Object oldValue , Object newValue ) throws PropertyVetoException { VetoableChangeSupport aVetoSupport = this . vetoSupport ; if ( aVetoSupport == null ) { return ; } aVetoSupport . fireVetoableChange ( propertyName , oldValue , newValue ) ; }
Support for reporting changes for constrained Object properties . This method can be called before a constrained property will be changed and it will send the appropriate PropertyChangeEvent to any registered VetoableChangeListeners .