public class ImportJournalEventPanel extends ContentPanel {

      private Messages constants = GWT.create(Messages.class);
      private TableData formData = new TableData();
      private FormPanel panel;
      private FormButtonBinding binding;
      private Button buttonOk;
      private FileUploadField file = new FileUploadField();      

      /**
      * Instantiates a new search journal event panel.
      */

      public ImportJournalEventPanel() {
            panel = new FormPanel() {
                  @Override
                  public List<Field<?>> getFields() {
                        List<Field<?>> baseFields = super.getFields();
                        baseFields.add(file);
                        return baseFields;
                  }

                  @Override
                  public boolean isValid(boolean preventMark) {
                        boolean baseValid = super.isValid(preventMark);
                        return baseValid && file.isValid();
                  }
            };

            String rootUrl = Registry.get(AppView.ROOT_URL);
            
            panel.setAction(rootUrl+"/Upload.do");
            panel.setEncoding(Encoding.MULTIPART);
            panel.setMethod(Method.POST);
            
            binding = new FormButtonBinding(panel);

            buttonOk = new Button(constants.button_ok(),
                        new SelectionListener<ButtonEvent>() {
                             @Override
                             public void componentSelected(ButtonEvent ce) {
                                   panel.submit();
                             }
                        });

            binding.addButton(buttonOk);

            setStylePanel();
            setWidgetPanel();
            setHandlers();

            add(panel);
      }

      private void setStylePanel() {
            setLayout(new FitLayout());
            setBodyBorder(false);
            setBorders(false);
            setHeaderVisible(false);

            formData.setPadding(3);

            panel.setHeaderVisible(false);
            panel.setFrame(true);
            panel.setLayout(new TableLayout(2));
            panel.setPadding(0);
            panel.setBodyBorder(false);
            panel.setBorders(false);
            panel.setAutoHeight(true);
            panel.setLabelAlign(LabelAlign.TOP);
            panel.setButtonAlign(HorizontalAlignment.CENTER);

            file.setAllowBlank(false);
//          file.getB
//          file.setRegex("/^.*\.(xls)$/");
//          regexText:'Only mp3 file supported'

      }

      private void setWidgetPanel() {
            panel.add(new Label(constants.journal_event_form_import()), formData);
            panel.add(file, formData);

            panel.addButton(buttonOk);
      }

      private void setHandlers() {
//          file.addDomHandler(new ChangeHandler() {             
//                @Override
//                public void onChange(ChangeEvent arg0) {
//                      Info.display("File Changed", "You selected " + file.getValue());
//                }                 
//          },ChangeEvent.getType());
            panel.addButton(new Button(constants.window_button_cancel(),
                        new SelectionListener<ButtonEvent>() {
                             @Override
                             public void componentSelected(ButtonEvent ce) {
                                   file.clear();
                                   panel.clear();
                                   Dispatcher.forwardEvent(AppEvents.WindowSearchHide);
                             }
                        }));
            panel.addListener(Events.Submit, new Listener<FormEvent>() {
                  public void handleEvent(FormEvent fe) {
                        String res = fe.getResultHtml();                     
                        if (res != null && res.contains("RESULT_OK")) {                                          
                        }
                        Dispatcher.forwardEvent(AppEvents.WindowSearchHide);
                  }
            });
      }

      @Override
      protected void onUnload() {
            super.onUnload();
            file.clear();
            panel.clear();
      }
}