      /**
       * The constants used in this Content Widget.
       */
      public static interface CwConstants extends Constants,
          ContentWidget.CwConstants {
        String cwAbsolutePanelClickMe();

        String cwAbsolutePanelDescription();

        String cwAbsolutePanelHelloWorld();

        String cwAbsolutePanelItemsToMove();

        String cwAbsolutePanelLeft();

        String cwAbsolutePanelName();

        String cwAbsolutePanelTop();

        String[] cwAbsolutePanelWidgetNames();
      }

      /**
       * An instance of the constants.
       */
      private CwConstants constants;

      /**
       * The input field used to set the left position of a {@link Widget}.
       */
      private TextBox leftPosBox = null;

      /**
       * The list box of items that can be repositioned.
       */
      private ListBox listBox = new ListBox();

      /**
       * The input field used to set the top position of a {@link Widget}.
       */
      private TextBox topPosBox = null;

      /**
       * A mapping between the name of a {@link Widget} and the widget in the
       * {@link AbsolutePanel}.
       */
      private Map<String, Widget> widgetMap = null;

      /**
       * Initialize this example.
       */
      @Override
      public Widget onInitialize() {
        // Create a new panel
        widgetMap = new LinkedHashMap<String, Widget>();
        absolutePanel = new AbsolutePanel();
        absolutePanel.setSize("250px", "250px");
        absolutePanel.ensureDebugId("cwAbsolutePanel");

        // Add an HTML widget to the panel
        String[] widgetNames = constants.cwAbsolutePanelWidgetNames();
        HTML text = new HTML(constants.cwAbsolutePanelHelloWorld());
        absolutePanel.add(text, 10, 20);
        widgetMap.put(widgetNames[0], text);

        // Add a Button to the panel
        Button button = new Button(constants.cwAbsolutePanelClickMe());
        absolutePanel.add(button, 80, 45);
        widgetMap.put(widgetNames[1], button);

        // Add a Button to the panel
        Grid grid = new Grid(2, 3);
        grid.setBorderWidth(1);
        for (int i = 0; i < 3; i++) {
          grid.setHTML(0, i, i + "");
          grid.setWidget(1, i, new Image(Showcase.images.gwtLogoThumb()));
        }
        absolutePanel.add(grid, 60, 100);
        widgetMap.put(widgetNames[2], grid);

        // Wrap the absolute panel in a DecoratorPanel
        DecoratorPanel absolutePanelWrapper = new DecoratorPanel();
        absolutePanelWrapper.setWidget(absolutePanel);

        // Create the options bar
        DecoratorPanel optionsWrapper = new DecoratorPanel();
        optionsWrapper.setWidget(createOptionsBar());

        // Add the components to a panel and return it
        HorizontalPanel mainLayout = new HorizontalPanel();
        mainLayout.setSpacing(10);
        mainLayout.add(optionsWrapper);
        mainLayout.add(absolutePanelWrapper);

        return mainLayout;
      }

      /**
       * Initialize the options panel after the {@link AbsolutePanel} has been
       * attached to the page.
       */
      @Override
      public void onInitializeComplete() {
        DeferredCommand.addCommand(new Command() {
          public void execute() {
            updateSelectedItem();
          }
        });
      }

      /**
       * Create an options panel that allows users to select a widget and reposition
       * it.
       *
       * @return the new options panel
       */
      private Widget createOptionsBar() {
        // Create a panel to move components around
        FlexTable optionsBar = new FlexTable();
        topPosBox = new TextBox();
        topPosBox.setWidth("3em");
        topPosBox.setText("100");
        leftPosBox = new TextBox();
        leftPosBox.setWidth("3em");
        leftPosBox.setText("60");
        listBox = new ListBox();
        optionsBar.setHTML(0, 0, constants.cwAbsolutePanelItemsToMove());
        optionsBar.setWidget(0, 1, listBox);
        optionsBar.setHTML(1, 0, constants.cwAbsolutePanelTop());
        optionsBar.setWidget(1, 1, topPosBox);
        optionsBar.setHTML(2, 0, constants.cwAbsolutePanelLeft());
        optionsBar.setWidget(2, 1, leftPosBox);

        // Add the widgets to the list box
        for (String name : widgetMap.keySet()) {
          listBox.addItem(name);
        }

        // Set the current item position when the user selects an item
        listBox.addChangeHandler(new ChangeHandler() {
          public void onChange(ChangeEvent event) {
            updateSelectedItem();
          }
        });

        // Move the item as the user changes the value in the left and top boxes
        KeyUpHandler repositionHandler = new KeyUpHandler() {
          public void onKeyUp(KeyUpEvent event) {
            repositionItem();
          }
        };
        topPosBox.addKeyUpHandler(repositionHandler);
        leftPosBox.addKeyUpHandler(repositionHandler);

        // Return the options bar
        return optionsBar;
      }

      /**
       * Reposition an item when the user changes the value in the top or left
       * position text boxes.
       */
      private void repositionItem() {
        // Get the selected item to move
        String name = listBox.getValue(listBox.getSelectedIndex());
        Widget item = widgetMap.get(name);

        // Reposition the item
        try {
          int top = Integer.parseInt(topPosBox.getText());
          int left = Integer.parseInt(leftPosBox.getText());
          absolutePanel.setWidgetPosition(item, left, top);
        } catch (NumberFormatException e) {
          // Ignore invalid user input
          return;
        }
      }

      /**
       * Update the top and left position text fields when the user selects a new
       * item to move.
       */
      private void updateSelectedItem() {
        String name = listBox.getValue(listBox.getSelectedIndex());
        Widget item = widgetMap.get(name);
        topPosBox.setText(absolutePanel.getWidgetTop(item) + "");
        leftPosBox.setText(absolutePanel.getWidgetLeft(item) + "");
      }