observable.h

См. документацию.

#pragma once
 
#include "iview.h"
#include <list>
#include <memory>
 
class  Observable {
public:
 
    Observable() = default;
    virtual ~Observable() = default;
 
    void subscribe(IViewSptr in_observer) noexcept {
        observers.push_back(in_observer);
    }
 
    void unsubscribe(IViewSptr in_observer) noexcept {
        observers.remove_if([in_observer](std::weak_ptr<IView> &obs) {
            return obs.expired() || obs.lock() == in_observer;
        });
    }
 
    void notifyUpdate() noexcept {
        for (auto &obs : observers) {
 
            if (auto sptr = obs.lock())
                sptr->update();
 
        }
    }
 
private:
    std::list<std::weak_ptr<IView>> observers;
};