void ViewerWindowBase::EnableBaseEditorMenuItems(bool enabled)
{
    int i;
    for (i=MID_SPLIT_BLOCK; i<=MID_SYNC_STRUCS_ON; ++i)
        menuBar->Enable(i, enabled);
    menuBar->Enable(MID_DRAG_HORIZ, enabled);
    if (!enabled) CancelBaseSpecialModesExcept(-1);
    menuBar->Enable(MID_UNDO, false);
    menuBar->Enable(MID_REDO, false);
    menuBar->Enable(MID_SHOW_GEOM_VLTNS,
        viewer->GetCurrentDisplay() && viewer->GetCurrentDisplay()->IsEditable());
    EnableDerivedEditorMenuItems(enabled);
}
 void CancelAllSpecialModesExcept(int id)
 {
     CancelBaseSpecialModesExcept(id);
     CancelDerivedSpecialModesExcept(id);
 }