Source:
private void initSecondaryToolbar() { SecondaryToolbar toolbar = new SecondaryToolbar("Environment Tab Second"); languageMenu_ = new ToolbarPopupMenu(); MenuItem rMenuItem = new MenuItem("R", () -> setActiveLanguage("R", true)); languageMenu_.addItem(rMenuItem); MenuItem pyMenuItem = new MenuItem("Python", () -> { dependencyManager_.withReticulate( "Viewing Python Objects", "Viewing Python objects", () -> setActiveLanguage("Python", true)); }); languageMenu_.addItem(pyMenuItem); languageButton_ = new ToolbarMenuButton( "R", ToolbarButton.NoTitle, (ImageResource) null, languageMenu_); toolbar.addLeftWidget(languageButton_); toolbar.addLeftSeparator(); environmentMenu_ = new EnvironmentPopupMenu(); environmentButton_ = new ToolbarMenuButton( friendlyEnvironmentName(), ToolbarButton.NoTitle, imageOfEnvironment(environmentName_, environmentIsLocal_), environmentMenu_); ElementIds.assignElementId(environmentButton_, ElementIds.MB_ENVIRONMENT_LIST); toolbar.addLeftWidget(environmentButton_); ThemeStyles styles = ThemeStyles.INSTANCE; toolbar.getWrapper().addStyleName(styles.tallerToolbarWrapper()); searchWidget_ = new SearchWidget("Search environment", new SuggestOracle() { @Override public void requestSuggestions(Request request, Callback callback) { callback.onSuggestionsReady( request, new Response(new ArrayList<Suggestion>())); } }); ElementIds.assignElementId(searchWidget_, ElementIds.SW_ENVIRONMENT); searchWidget_.addValueChangeHandler(new ValueChangeHandler<String>() { @Override public void onValueChange(ValueChangeEvent<String> event) { objects_.setFilterText(event.getValue()); } }); if (!RStudioThemes.isFlat(prefs_)) { searchWidget_.getElement().getStyle().setMarginTop(1, Unit.PX); } toolbar.addRightWidget(searchWidget_); secondaryToolbar_ = toolbar; }

Target:
private void initSecondaryToolbar() { SecondaryToolbar toolbar = new SecondaryToolbar("Environment Tab Second"); languageMenu_ = new ToolbarPopupMenu(); MenuItem rMenuItem = new MenuItem("R", () -> setActiveLanguage("R", true)); languageMenu_.addItem(rMenuItem); MenuItem pyMenuItem = new MenuItem("Python", () -> { dependencyManager_.withReticulate( "Viewing Python Objects", "Viewing Python objects", () -> setActiveLanguage("Python", true)); }); languageMenu_.addItem(pyMenuItem); languageButton_ = new ToolbarMenuButton( "R", ToolbarButton.NoTitle, (ImageResource) null, languageMenu_); toolbar.addLeftWidget(languageButton_); toolbar.addLeftSeparator(); environmentMenu_ = new EnvironmentPopupMenu(); environmentButton_ = new ToolbarMenuButton( friendlyEnvironmentName(), ToolbarButton.NoTitle, imageOfEnvironment(environmentName_, environmentIsLocal_), environmentMenu_); ElementIds.assignElementId(environmentButton_, ElementIds.MB_ENVIRONMENT_LIST); toolbar.addLeftWidget(environmentButton_); ThemeStyles styles = ThemeStyles.INSTANCE; toolbar.getWrapper().addStyleName(styles.tallerToolbarWrapper()); SearchWidget searchWidget = new SearchWidget("Search environment", new SuggestOracle() { @Override public void requestSuggestions(Request request, Callback callback) { callback.onSuggestionsReady( request, new Response(new ArrayList<Suggestion>())); } }); ElementIds.assignElementId(searchWidget, ElementIds.SW_ENVIRONMENT); searchWidget.addValueChangeHandler(new ValueChangeHandler<String>() { @Override public void onValueChange(ValueChangeEvent<String> event) { objects_.setFilterText(event.getValue()); } }); if (!RStudioThemes.isFlat(prefs_)) { searchWidget.getElement().getStyle().setMarginTop(1, Unit.PX); } toolbar.addRightWidget(searchWidget); secondaryToolbar_ = toolbar; }