2.6 KiB
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| delegate_observable |
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Header: delegate_observable.h
Since: TBC
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etl::delegate_observable is a variation on the observer pattern idea, but using delegates as the callback mechanism.
template <typename TNotification, size_t Max_Observers>
class delegate_observable
TNotification is the notification type.
Max_Observers is the maximum number of observers that can be handled.
Template deduction guide
template <typename TNotification, typename... TDelegates>
delegate_observable(TNotification, TDelegates...)
-> delegate_observable<TNotification, sizeof...(TDelegates)>;
Example
etl::delegate<void(int)> delegate1;
etl::delegate<void(int)> delegate2;
etl::delegate_observable observable(int{}, delegate1, delegate2);
Public types
| Type | Description |
|---|---|
delegate_type |
The type of delegate used in this observer. |
size_type |
The type used internally for sizes. |
notification_type |
The type of the notification. |
Construction
ETL_CONSTEXPR14 delegate_observable()
Description
Default constructor.
template <typename... TDelegate>
ETL_CONSTEXPR14 delegate_observable(TDelegate&&... delegates)
Description
Construct from a collection of observers.
template <typename... TDelegate>
ETL_CONSTEXPR14 delegate_observable(notification_type, TDelegate&&... delegates)
Description
Construct from notification type and a list of observers.
Variant for template deduction guide.
The notification value is ignored. It is here to allow deduction of the notification type for the template deduction guide.
Modifiers
ETL_CONSTEXPR14 bool add_observer(delegate_type observer)
Description
Add an observer to the list.
Return
true if the observer was removed, false if not.
ETL_CONSTEXPR14 bool remove_observer(const delegate_type& observer)
Description
Remove a particular observer from the list.
Return
`true if the observer was removed, false if not.
ETL_CONSTEXPR14 void clear_observers()
Description
Clear all observers.
Status
ETL_CONSTEXPR14 size_type number_of_observers() const
Return
The number of observers.
Notofication
ETL_CONSTEXPR14 void notify_observers(notification_type n) const
Description
Notify all of the observers, sending them the notification.