class Observer

Defined in: C4Observable.h

The Observer class encapsulates an object pointer and callback function for an observer.

Definition

template <class observerType, class observableType> class Observer :

public ObserverBase<observableType, typename observableType::ObservableEventType>

Template Parameters

`observerType`	The type of the class for which a notification function is called when an event occurs.
`observableType`	The type of the class that is being observed. This parameter should be the type of the class that inherits directly from the `Observable` class.

Constructor

template <class eventType> Observer(observerType *observer, void (observerType::*callback)(observableType *, eventType));

Observer(observerType *observer, void (observerType::*callback)(observableType *));

Parameters

`observer`	A pointer to the object for which a notification function is called when an event occurs.
`callback`	A pointer to a member function (the notification function) of the object specified by the `observer` parameter that is called when an event occurs.

Description

The Observer class encapsulates a member function of an observer object. Observers are installed on observable objects by calling the Observable::AddObserver function. Once installed, the member function stored in the observer object is called each time an event is posted for the observable object.

The first parameter of the member function belonging to the observer object is a pointer to the object being observed. If the event type of the observable object is not void, then the event is passed as the second parameter to the member function. Otherwise, the member function should not take a second parameter.

Base Classes

ObserverBase<observableType, typename observableType::ObservableEventType> Used internally.