private List<String> validate() {
   List<String> errors = new ArrayList<String>();
   if (selectionListbox.getItemCount() == 0 && !ViewUtil.isTextPopulated(dbInstructionArea)) {
     errors.add(TEXT_CONSTANTS.noDBSurveyMandatory());
   }
   if (!ViewUtil.isTextPopulated(notificationEmailBox)) {
     errors.add(TEXT_CONSTANTS.emailMandatory());
   }
   return errors;
 }
 public BootstrapGeneratorWidget() {
   contentPanel = new VerticalPanel();
   contentPanel.setWidth("800px");
   surveyService = GWT.create(SurveyService.class);
   addSurveyButton = new Button(TEXT_CONSTANTS.addSelected());
   addSurveyButton.addClickHandler(this);
   generateFileButton = new Button(TEXT_CONSTANTS.generate());
   generateFileButton.addClickHandler(this);
   removeButton = new Button(TEXT_CONSTANTS.removeSelected());
   removeButton.addClickHandler(this);
   CaptionPanel selectorPanel = new CaptionPanel(TEXT_CONSTANTS.selectSurveyForInclusion());
   HorizontalPanel temp = new HorizontalPanel();
   selectionWidget = new SurveySelectionWidget(Orientation.HORIZONTAL, TerminalType.SURVEY);
   temp.add(selectionWidget);
   temp.add(addSurveyButton);
   selectorPanel.add(temp);
   contentPanel.add(selectorPanel);
   CaptionPanel zipPanel = new CaptionPanel(TEXT_CONSTANTS.fileContents());
   selectionListbox = new ListBox(true);
   selectionListbox.setVisibleItemCount(DEFAULT_ITEM_COUNT);
   VerticalPanel zipPanelContent = new VerticalPanel();
   HorizontalPanel selectedSurveyPanel = new HorizontalPanel();
   ViewUtil.installFieldRow(
       selectedSurveyPanel, TEXT_CONSTANTS.selectedSurveys(), selectionListbox, LABEL_STYLE);
   selectedSurveyPanel.add(removeButton);
   zipPanelContent.add(selectedSurveyPanel);
   temp = new HorizontalPanel();
   includeDbScriptBox = new CheckBox();
   includeDbScriptBox.addClickHandler(this);
   ViewUtil.installFieldRow(temp, TEXT_CONSTANTS.includeDB(), includeDbScriptBox, LABEL_STYLE);
   zipPanelContent.add(temp);
   dbInstructionArea = new TextArea();
   dbInstructionArea.setVisible(false);
   zipPanelContent.add(dbInstructionArea);
   temp = new HorizontalPanel();
   notificationEmailBox = new TextBox();
   ViewUtil.installFieldRow(
       temp, TEXT_CONSTANTS.notificationEmail(), notificationEmailBox, LABEL_STYLE);
   zipPanelContent.add(temp);
   zipPanelContent.add(generateFileButton);
   zipPanel.add(zipPanelContent);
   contentPanel.add(zipPanel);
   initWidget(contentPanel);
 }