using System.Collections;
namespace Templates.Observer {

 public class Observer {                      

   private Subject mySubject;                 
                                              
   public Observer (Subject s){               
     mySubject = s;
   }   

   public void Update(){                      
      // ...                                  

      SubjectState state = mySubject.GetState();   
                                                   
      //   if (the state is interesting){
      //      react on state change
      //   }
   }
 }
}

 
 
 
The Observer class.
 
A reference to the corresponding 
Subject.
The constructor of Observer.
 
 
 
The Update method, activated by
the subject via Notify.
 
Sends a message back to the subject,
asking what really happend.