code: protected void readOnlyUpdated() {
  		boolean localReadOnly = isReadOnly();
  		if (hasChanged(oldReadOnly, localReadOnly)) {
  			oldReadOnly = localReadOnly;
  			firePropertyChange(READONLY_PROPERTY, !localReadOnly, localReadOnly);
  		}
  	}
docs: Fires the necessary property change event for changes to the readOnly
  property. Must be called whenever the value of readOnly is changed.