DockLayoutPanel masterLayout = new DockLayoutPanel(Unit.PX);
    masterLayout.addNorth(buildHeaderPanel(), 53);
    masterLayout.addNorth(buildUserInfoPanel(), 24);
    masterLayout.addNorth(actionBarPanel, 48);
    masterLayout.addSouth(buildFooterPanel(), 32);
    ScrollPanel scrollPanel = new ScrollPanel();
    scrollPanel.add(appPanel);
    masterLayout.add(scrollPanel);
    initWidget(masterLayout);