private String handleKeyStoreWorkspaceSelection( Shell parent ) {
ILabelProvider lp = new WorkbenchLabelProvider();
ITreeContentProvider cp = new WorkbenchContentProvider();
ElementTreeSelectionDialog dialog = new ElementTreeSelectionDialog( parent, lp, cp );
dialog.setValidator( new ISelectionStatusValidator() {
@Override
public IStatus validate( final Object[] selection ) {
if ( selection.length > 1 ) {
return new Status( IStatus.ERROR, JavaFXUIPlugin.PLUGIN_ID, "Only one file allowed." );