add_button.setFont(skin.getButtonFont());
add_button.setImage(SWTImageRepository.getImage("add.png"));
add_button.setText(_._("mainwindow.sharedtab.button.add"));
add_button.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
add_button.setAlignment(SWT.LEFT);
add_button.addSelectionListener(new SelectionAdapter() {
public void widgetSelected(SelectionEvent event) {
DirectoryDialog dir_dialog = new DirectoryDialog (getShell(),SWT.MULTI | SWT.OPEN);
String directory = dir_dialog.open();
if (directory == null) return ;
java.util.List<File> shared_dirs = null;