- Initial implementation of the basic Observer System

Author: LK-Simon

src/ESPressio_IObservable.hpp

@@ -18,12 +18,14 @@ namespace ESPressio {
                 virtual void Unregister() = 0;
                 /// Will return a `weak_ptr` to the `IObservable`
                 virtual std::weak_ptr<IObservable> GetObservable() = 0;
+                /// Will return a `weak_ptr` to the `IObserver`
+                virtual std::weak_ptr<IObserver> GetObserver() = 0;
         };
 
         class IObservable : public std::enable_shared_from_this<IObservable> {
             public:
                 /// Will Register the`IObserver` with this `IObservable`
-                virtual void RegisterObserver(IObserver* observer) = 0;
+                virtual IObserverHandle* RegisterObserver(IObserver* observer) = 0;
                 /// Will Unregister the `IObserver` from this `IObservable`
                 virtual void UnregisterObserver(IObserver* observer) = 0;
                 /// Will return `true` if the `IObserver` is registered with this `IObservable`

src/ESPressio_Observable.hpp

@@ -5,6 +5,7 @@
 
 #include "ESPressio_IObservable.hpp"
 #include "ESPressio_IObserver.hpp"
+#include "ESPressio_Observer.hpp"
 
 namespace ESPressio {
 
@@ -31,9 +32,12 @@ namespace ESPressio {
                     }
                 }
             public:
-                virtual void RegisterObserver(IObserver* observer) {
-                    if (IsObserverRegistered(observer)) { return; }
+                virtual IObserverHandle* RegisterObserver(IObserver* observer) {
+                    for (auto thisObserver : _observers) {
+                        if (thisObserver == observer) { return new ObserverHandle(this, observer); }
+                    }
                     _observers.push_back(observer);
+                    return new ObserverHandle(this, observer);
                 }
 
                 virtual void UnregisterObserver(IObserver* observer) {

src/ESPressio_ObserverHandle.hpp

@@ -2,6 +2,7 @@
 
 #include <memory>
 #include "ESPressio_IObservable.hpp"
+#include "ESPressio_IObserver.hpp"
 
 namespace ESPressio {
 
@@ -10,19 +11,28 @@ namespace ESPressio {
         class ObserverHandle : public IObserverHandle {
             private:
                 std::weak_ptr<IObservable> _observable;
+                IObserver* _observer;
             public:
-                ObserverHandle(std::weak_ptr<IObservable> observable) : _observable(observable) {}
-                ObserverHandle(IObservable* observable) : _observable(observable->shared_from_this()) {}
+                ObserverHandle(std::weak_ptr<IObservable> observable, IObserver* observer) : _observable(observable), _observer(observer) {}
+                ObserverHandle(IObservable* observable, IObserver* observer) : _observable(observable->shared_from_this()), _observer(observer) {}
+
+                ~ObserverHandle() {
+                    Unregister();
+                }
 
                 virtual void Unregister() {
                     std::shared_ptr<IObservable> observable = _observable.lock();
                     if (!observable) { return; }
-                    observable->UnregisterObserver(this);
+                    observable->UnregisterObserver(_observer);
                 }
 
                 virtual std::weak_ptr<IObservable> GetObservable() {
                     return _observable;
                 }
+
+                virtual IObserver* GetObserver() {
+                    return _observer;
+                }
         };
 
     }