ServiceTrackerCustomizer< T > Struct Template Reference

The ServiceTrackerCustomizer interface allows a ServiceTracker to customize the service objects that are tracked. More...

Inheritance diagram for ServiceTrackerCustomizer< T >:

Public Member Functions
virtual	~ServiceTrackerCustomizer ()
virtual T	AddingService (const ServiceReference &reference)=0
	A service is being added to the ServiceTracker. More...
virtual void	ModifiedService (const ServiceReference &reference, T service)=0
	A service tracked by the ServiceTracker has been modified. More...
virtual void	RemovedService (const ServiceReference &reference, T service)=0
	A service tracked by the ServiceTracker has been removed. More...

Detailed Description

template<class T = us::Base*>
struct ServiceTrackerCustomizer< T >

The ServiceTrackerCustomizer interface allows a ServiceTracker to customize the service objects that are tracked.

A ServiceTrackerCustomizer is called when a service is being added to a ServiceTracker. The ServiceTrackerCustomizer can then return an object for the tracked service. A ServiceTrackerCustomizer is also called when a tracked service is modified or has been removed from a ServiceTracker.

The methods in this interface may be called as the result of a ServiceEvent being received by a ServiceTracker. Since ServiceEvents are synchronously delivered, it is highly recommended that implementations of these methods do not register (ModuleContext::RegisterService), modify ( ServiceRegistration::SetProperties) or unregister ( ServiceRegistration::Unregister) a service while being synchronized on any object.

The ServiceTracker class is thread-safe. It does not call a ServiceTrackerCustomizer while holding any locks. ServiceTrackerCustomizer implementations must also be thread-safe.

Template Parameters

T	The type of the tracked object.

Remarks

This class is thread safe.

Constructor & Destructor Documentation

template<class T = us::Base*>

virtual ServiceTrackerCustomizer< T >::~ServiceTrackerCustomizer ( )

inlinevirtual

Member Function Documentation

template<class T = us::Base*>

virtual T ServiceTrackerCustomizer< T >::AddingService ( const ServiceReference &  reference )

pure virtual

A service is being added to the ServiceTracker.

This method is called before a service which matched the search parameters of the ServiceTracker is added to the ServiceTracker. This method should return the service object to be tracked for the specified ServiceReference. The returned service object is stored in the ServiceTracker and is available from the GetService and GetServices methods.

Parameters

reference

The reference to the service being added to the ServiceTracker.

Returns

The service object to be tracked for the specified referenced service or 0 if the specified referenced service should not be tracked.

Implemented in ServiceTracker< S, T >.

template<class T = us::Base*>

virtual void ServiceTrackerCustomizer< T >::ModifiedService ( const ServiceReference &  reference, T  service  )

pure virtual

A service tracked by the ServiceTracker has been modified.

This method is called when a service being tracked by the ServiceTracker has had it properties modified.

Parameters

reference	The reference to the service that has been modified.
service	The service object for the specified referenced service.

Implemented in ServiceTracker< S, T >.

template<class T = us::Base*>

virtual void ServiceTrackerCustomizer< T >::RemovedService ( const ServiceReference &  reference, T  service  )

pure virtual

A service tracked by the ServiceTracker has been removed.

This method is called after a service is no longer being tracked by the ServiceTracker.

Parameters

reference	The reference to the service that has been removed.
service	The service object for the specified referenced service.

Implemented in ServiceTracker< S, T >.