fkie_message_filters::SubscriberBase Class Reference

Base class for ROS subscribers in a filter pipeline. More...

#include <fkie_message_filters/subscriber_base.h>

Inheritance diagram for fkie_message_filters::SubscriberBase:

Public Member Functions
virtual void	subscribe ()
	Subscribe to the configured ROS topic. More...
virtual void	subscribe_on_demand (PublisherBase &pub)
	Subscribe to the configured ROS topic whenever the given publisher is active. More...
virtual std::string	topic () const =0
	Return the subscribed topic name. More...
virtual void	unsubscribe ()
	Unsubscribe from the configured ROS topic. More...

Protected Member Functions
virtual bool	is_configured () const =0
	Check if the subscriber is properly configured. More...
void	link_with_publisher (PublisherBase &pub)
	Add self to the list of subscribers which are controlled by a publisher. More...
virtual void	subscribe_impl ()=0
	Implement how to subscribe to the configured ROS topic. More...
void	unlink_from_publisher ()
	Remove self from the list of subscribers which are controlled by a publisher. More...
virtual void	unsubscribe_impl ()=0
	Implement how to unsubscribe from the configured ROS topic. More...

Detailed Description

Base class for ROS subscribers in a filter pipeline.

ROS subscribers and publishers can act as sources and sinks in the message filter library. This class provides some basic functionality for on-demand subscriptions.

See also

Subscriber

Member Function Documentation

is_configured()

virtual bool fkie_message_filters::SubscriberBase::is_configured ( ) const

protectedpure virtual

Check if the subscriber is properly configured.

This virtual method must be overridden in derived classes.

Return values

true	if subscribe_impl() or unsubscribe_impl() may be called and have all the information they need to subscribe or unsubscribe, respectively.
false	otherwise

Exceptions

Depends on the implementation.

Implemented in fkie_message_filters::Subscriber< M, Translate >, fkie_message_filters::CameraSubscriber, and fkie_message_filters::ImageSubscriber.

link_with_publisher()

void fkie_message_filters::SubscriberBase::link_with_publisher ( PublisherBase &  pub )

protected

Add self to the list of subscribers which are controlled by a publisher.

A subscriber can be linked with one publisher only. Any previously linked publisher is unlinked first.

• pub publisher

Exceptions

Propagates exceptions raised by the implementation of the abstract class methods.

See also

PublisherBase::link_with_subscriber()

subscribe()

void fkie_message_filters::SubscriberBase::subscribe ( )

virtual

Subscribe to the configured ROS topic.

This method does nothing if no ROS topic was configured or if the subscriber is subscribed already. Cancels the effect of subscribe_on_demand(), i.e. the subscriber will remain subscribed permanently.

Exceptions

Propagates exceptions raised by the implementation of the abstract class methods.

subscribe_impl()

virtual void fkie_message_filters::SubscriberBase::subscribe_impl ( )

protectedpure virtual

Implement how to subscribe to the configured ROS topic.

This virtual method must be overridden in derived classes to actually subscribe to a topic. It should do nothing if it is subscribed to a topic already.

Exceptions

Depends on the implementation.

Implemented in fkie_message_filters::Subscriber< M, Translate >, fkie_message_filters::CameraSubscriber, and fkie_message_filters::ImageSubscriber.

subscribe_on_demand()

void fkie_message_filters::SubscriberBase::subscribe_on_demand ( PublisherBase &  pub )

virtual

Subscribe to the configured ROS topic whenever the given publisher is active.

This method does nothing if no ROS topic was configured. Otherwise, it will immediately subscribe or unsubscribe depending on the publisher's current state. If the publisher becomes active or inactive, the subscriber's state will update accordingly.

• pub publisher

Exceptions

Propagates exceptions raised by the implementation of the abstract class methods.

topic()

virtual std::string fkie_message_filters::SubscriberBase::topic ( ) const

pure virtual

Return the subscribed topic name.

Exceptions

Depends on the implementation.

Implemented in fkie_message_filters::Subscriber< M, Translate >, fkie_message_filters::CameraSubscriber, and fkie_message_filters::ImageSubscriber.

unlink_from_publisher()

void fkie_message_filters::SubscriberBase::unlink_from_publisher ( )

protected

Remove self from the list of subscribers which are controlled by a publisher.

This will not affect the current subscription state. It will only prevent further updates from the previously linked publisher.

Exceptions

Does not throw any exceptions.

unsubscribe()

void fkie_message_filters::SubscriberBase::unsubscribe ( )

virtual

Unsubscribe from the configured ROS topic.

You can call subscribe() afterwards to re-subscribe to the ROS topic. This method does nothing if the subscriber is not subscribed to any ROS topic. Cancels the effect of subscribe_on_demand(), i.e. the subscriber will remain unsubscribed permanently.

Exceptions

Propagates exceptions raised by the implementation of the abstract class methods.

unsubscribe_impl()

virtual void fkie_message_filters::SubscriberBase::unsubscribe_impl ( )

protectedpure virtual

Implement how to unsubscribe from the configured ROS topic.

This virtual method must be overridden in derived classes to actually unsubscribe from a topic. It should do nothing if it is not subscribed in the first place.

Exceptions

Depends on the implementation.

Implemented in fkie_message_filters::Subscriber< M, Translate >, fkie_message_filters::CameraSubscriber, and fkie_message_filters::ImageSubscriber.

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The documentation for this class was generated from the following files:

• include/fkie_message_filters/subscriber_base.h
• src/publisher_subscriber_base.cpp