fileChooser.setFileFilter(new XMLFileFilter());
fileChooser.setMultiSelectionEnabled(true);
if (source == null) return null;
int returnVal = fileChooser.showOpenDialog(source);
if (returnVal == FileChooser.APPROVE_OPTION) {
File[] rootFileOrDir = fileChooser.getSelectedFiles();
List<File> files = Utilities.filterSelectedFiles(Arrays.asList(rootFileOrDir));
//set the owner