public void showContainerSizePanel() {
    CaptionPanel bodySize = new CaptionPanel(constants.containerSizeTitle());
    bodySize.setWidth("185px");

    final VerticalPanel content = new VerticalPanel();

    containerSizeListBox = new CustomListBox();

    content.add(containerSizeListBox);
    bodySize.setContentWidget(content);

    HorizontalPanel setSizePanel = new HorizontalPanel();

    setSizeDisclosurePanel = new DisclosurePanel(constants.sizeInPixel());
    setSizeDisclosurePanel.setAnimationEnabled(true);
    setSizeDisclosurePanel.setOpen(true);
    setSizeDisclosurePanel.setVisible(false);

    setSizeDisclosurePanel.add(setSizePanel);

    customSizeTextBox = new TextBox();
    customSizeTextBox.setWidth("50px");
    setSizePanel.add(customSizeTextBox);

    validCustomSizeButton = new Button("OK");

    setSizePanel.add(validCustomSizeButton);

    content.add(setSizeDisclosurePanel);

    builderContent.add(bodySize);
  }