protected void InstallViewChangeNotificator(IViewChangeNotificator viewChangeNotificator)
 {
     if (_viewChangeNotificator != null)
     {
         UninstallViewChangeNotificator();
     }
     _viewChangeNotificator = viewChangeNotificator;
     if (_viewChangeNotificator == null)
     {
         return;
     }
     _viewChangeNotificator.Changed += ViewChanged;
     _viewChangeNotificator.Install();
 }
 protected void UninstallViewChangeNotificator()
 {
   if (_viewChangeNotificator == null)
     return;
   _viewChangeNotificator.Changed -= ViewChanged;
   _viewChangeNotificator.Dispose();
   _viewChangeNotificator = null;
 }
 protected void InstallViewChangeNotificator(IViewChangeNotificator viewChangeNotificator)
 {
   if (_viewChangeNotificator != null)
     UninstallViewChangeNotificator();
   _viewChangeNotificator = viewChangeNotificator;
   if (_viewChangeNotificator == null)
     return;
   _viewChangeNotificator.Changed += ViewChanged;
   _viewChangeNotificator.Install();
 }