code: public void addButtonToFront(Widget w) {
  
          m_buttonPanel.insert(w, 0);
          if (CmsCoreProvider.get().isIe7()) {
              m_buttonPanel.getElement().getStyle().setWidth(m_buttonPanel.getWidgetCount() * 22, Unit.PX);
          }
      }
docs: Adds a widget to the front of the button panel.<p>
  
  @param w the widget to add