public Widget onInitialize() {
// Get the images.
Images images = (Images) GWT.create(Images.class);
// Create a new stack layout panel.
StackLayoutPanel stackPanel = new StackLayoutPanel(Unit.EM);
stackPanel.setPixelSize(200, 400);
// Add the Mail folders.
Widget mailHeader = createHeaderWidget(
constants.cwStackLayoutPanelMailHeader(), images.mailgroup());
stackPanel.add(createMailItem(images), mailHeader, 4);
// Add a list of filters.
Widget filtersHeader = createHeaderWidget(
constants.cwStackLayoutPanelFiltersHeader(), images.filtersgroup());
stackPanel.add(createFiltersItem(), filtersHeader, 4);
// Add a list of contacts.
Widget contactsHeader = createHeaderWidget(
constants.cwStackLayoutPanelContactsHeader(), images.contactsgroup());
stackPanel.add(createContactsItem(images), contactsHeader, 4);
// Return the stack panel.
stackPanel.ensureDebugId("cwStackLayoutPanel");
return stackPanel;
}