gt: 	protected void setSplitWindowEnabled(final boolean enabled) {
context: package de.eisfeldj.augendiagnosefx.controller;
  
  import java.net.URL;
  import java.util.ResourceBundle;
  
  import de.eisfeldj.augendiagnosefx.Application;
  import de.eisfeldj.augendiagnosefx.util.DialogUtil;
  import de.eisfeldj.augendiagnosefx.util.FxmlConstants;
  import de.eisfeldj.augendiagnosefx.util.Logger;
  import de.eisfeldj.augendiagnosefx.util.PreferenceUtil;
  import de.eisfeldj.augendiagnosefx.util.ResourceConstants;
  import de.eisfeldj.augendiagnosefx.util.ResourceUtil;
  import de.eisfeldj.augendiagnosefx.util.VersioningUtil;
  
  import javafx.event.ActionEvent;
  import javafx.event.EventHandler;
  import javafx.fxml.FXML;
  import javafx.fxml.Initializable;
  import javafx.scene.Parent;
  import javafx.scene.control.CheckMenuItem;
  import javafx.scene.control.MenuBar;
  import javafx.scene.control.MenuItem;
  
  import static de.eisfeldj.augendiagnosefx.util.PreferenceUtil.KEY_SHOW_COMMENT_PANE;
  import static de.eisfeldj.augendiagnosefx.util.PreferenceUtil.KEY_SHOW_OVERLAY_PANE;
  import static de.eisfeldj.augendiagnosefx.util.PreferenceUtil.KEY_SHOW_SPLIT_WINDOW;
  
  /**
   * BaseController class for the menu.
   */
  public class MenuController extends BaseController implements Initializable {
  	/**
  	 * The main menu bar.
  	 */
  	@FXML
  	private MenuBar mMenuBar;
  
  	/**
  	 * The Menu entry "Close".
  	 */
  	@FXML
  	private MenuItem mMenuClose;
  
  	/**
  	 * The Menu entry "Overlay Pane".
  	 */
  	@FXML
  	private CheckMenuItem mMenuOverlayPane;
  
  	/**
  	 * Get the menu overlay pane.
  	 *
  	 * @return The menu overlay pane.
  	 */
  	public final CheckMenuItem getMenuOverlayPane() {
  		return mMenuOverlayPane;
  	}
  
  	/**
  	 * The Menu entry "Comment Pane".
  	 */
  	@FXML
  	private CheckMenuItem mMenuCommentPane;
  
  	/**
  	 * The Menu entry "Split window".
  	 */
  	@FXML
  	private CheckMenuItem mMenuSplitWindow;
  
  	@Override
  	public final Parent getRoot() {
  		return mMenuBar;
  	}
  
  	/**
  	 * Get the main controller instance.
  	 *
  	 * @return The main controller instance.
  	 */
  	public static MenuController getInstance() {
  		try {
  			return getController(MenuController.class);
  		}
  		catch (TooManyControllersException | MissingControllerException e) {
  			Logger.error("Could not find menu controller", e);
  			throw new RuntimeException(e);
  		}
  	}
  
  	/**
  	 * Handler for menu entry "Exit".
  	 *
  	 * @param event
  	 *            The action event.
  	 */
  	@FXML
  	protected final void exitApplication(final ActionEvent event) {
  		Application.exitAfterConfirmation();
  	}
  
  	/**
  	 * Handler for menu entry "Preferences".
  	 *
  	 * @param event
  	 *            The action event.
  	 */
  	@FXML
  	public final void showPreferences(final ActionEvent event) {
  		DialogUtil.displayPreferencesDialog();
  	}
  
  	/**
  	 * Handler for menu entry "Comment pane".
  	 *
  	 * @param event
  	 *            The action event.
  	 */
  	@FXML
  	public final void toggleCommentPane(final ActionEvent event) {
  		boolean showComment = !PreferenceUtil.getPreferenceBoolean(KEY_SHOW_COMMENT_PANE);
  		PreferenceUtil.setPreference(KEY_SHOW_COMMENT_PANE, showComment);
  		mMenuCommentPane.setSelected(showComment);
  		for (DisplayImageController controller : getControllers(DisplayImageController.class)) {
  			controller.showCommentPane(showComment);
  		}
  		MainController.getInstance().setCommentButtonStatus(showComment);
  	}
  
  	/**
  	 * Handler for menu entry "Overlay pane".
  	 *
  	 * @param event
  	 *            The action event.
  	 */
  	@FXML
  	public final void toggleOverlayPane(final ActionEvent event) {
  		PreferenceUtil.setPreference(KEY_SHOW_OVERLAY_PANE, mMenuOverlayPane.isSelected());
  		for (DisplayImageController controller : getControllers(DisplayImageController.class)) {
  			controller.showOverlayPane(mMenuOverlayPane.isSelected());
  		}
  	}
  
  	/**
  	 * Handler for menu entry "Split window".
  	 *
  	 * @param event
  	 *            The action event.
  	 */
  	@FXML
  	public final void toggleSplitWindow(final ActionEvent event) {
  		boolean split = !PreferenceUtil.getPreferenceBoolean(KEY_SHOW_SPLIT_WINDOW);
  		PreferenceUtil.setPreference(KEY_SHOW_SPLIT_WINDOW, split);
  		mMenuSplitWindow.setSelected(split);
  		MainController.getInstance().setPaneButtonStatus(split);
  		if (MainController.getInstance().hasClosablePage()) {
  			if (split) {
  				MainController.getInstance().setSplitPane(FxmlConstants.FXML_DISPLAY_PHOTOS);
  			}
  			else {
  				MainController.getInstance().setSinglePane();
  			}
  		}
  	}
  
  	/**
  	 * Handler for menu entry "Online Help".
  	 *
  	 * @param event
  	 *            The action event.
  	 */
  	@FXML
  	public final void showHelp(final ActionEvent event) {
  		Application.getApplicationHostServices().showDocument(
  				ResourceUtil.getString(ResourceConstants.DOCUMENTATION_URL));
  	}
  
  	/**
  	 * Handler for menu entry "Check for updates".
  	 *
  	 * @param event
  	 *            The action event.
  	 */
  	@FXML
  	public final void checkUpdates(final ActionEvent event) {
  		VersioningUtil.checkForNewerVersion(true);
  	}
  
  	/**
  	 * Handler for menu entry "About".
  	 *
  	 * @param event
  	 *            The action event.
  	 */
  	@FXML
  	public final void displayAboutMessage(final ActionEvent event) {
  		DialogUtil.displayInfo(ResourceConstants.MESSAGE_INFO_APP_ABOUT,
  				VersioningUtil.CURRENT_VERSION.getVersionString());
  	}
  
  	/**
  	 * Set the enablement of the comment pane menu entry.
  	 *
  	 * @param enabled the enablement status.
  	 */
  	public final void setCommentPaneMenuEnablement(final boolean enabled) {
  		mMenuCommentPane.setDisable(!enabled);
  		MainController.getInstance().setCommentButtonVisibility(enabled);
  	}
  
  	/**
  	 * Set the enablement of the splitWindow property.
  	 *
  	 * @param enabled the target status of the enablement.
  	 */
  