int endRow, int endCol) {
   private void fireScreenChanged(int which, int startRow, int startCol,                                 int endRow, int endCol) {      if (listeners != null) {         int size = listeners.size();         for (int i = 0; i < size; i++) {            ScreenListener target =                    (ScreenListener)listeners.elementAt(i);            target.onScreenChanged(1,startRow,startCol,endRow,endCol);         }      }      dirtyScreen.setBounds(lenScreen,0,0,0);   }