    void undoStackCleanChanged(bool clean);
    void undoStackIndexChanged(int index);
    void onlineHelp();
  
    VideoWidget *video_widget = nullptr;
    QDockWidget *video_dock;
    MessagesWidget *messages_widget;
    CenterWidget *center_widget;
    ChartsWidget *charts_widget;
 
</s>
  void updateStatus();
    void undoStackCleanChanged(bool clean);
    void undoStackIndexChanged(int index);
    void onlineHelp();
  void updateStatus();
  
    VideoWidget *video_widget = nullptr;
    QDockWidget *video_dock;
    MessagesWidget *messages_widget;
    CenterWidget *center_widget;
    ChartsWidget *charts_widget;
keep keep add keep keep keep keep keep keep
 cabana: dispaly current FPS & cached minitues on statusbar (#27430)

dispaly current FPS & cached minitues on statusbar
tools/cabana/mainwin.h