text: //
  //  OAObservableProtocol.h
  //  OsmAnd
  //
  //  Created by Alexey Pelykh on 2/25/14.
  //  Copyright (c) 2014 OsmAnd. All rights reserved.
  //
  
  #import <Foundation/Foundation.h>
  
  @protocol OAObserverProtocol;
  
  @protocol OAObservableProtocol <NSObject>
  
  @required
  - (void)registerObserver:(id<OAObserverProtocol>)observer;
  - (void)unregisterObserver:(id<OAObserverProtocol>)observer;
  
  @optional
  - (void)notifyEvent;
  - (void)notifyEventWithKey:(id)key;
  - (void)notifyEventWithKey:(id)key andValue:(id)value;
  - (void)notifyEventWithKey:(id)key value1:(id)value1 value2:(id)value2;
  
  @end
  