PresenceHandler (Vaadin Platform (vaadin-platform-javadoc) 23.3.4 API)

All Superinterfaces:

Serializable

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.
```
@FunctionalInterface
public interface PresenceHandler
extends Serializable
```
Functional interface that defines how to handle user presence changes in a topic.

Since:

4.0

Author:

Vaadin Ltd

See Also:

PresenceManager.setPresenceHandler(PresenceHandler)

Nested Class Summary

Nested Classes
Modifier and Type Interface Description

static interface PresenceHandler.PresenceContext
The context of the user presence.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`Registration`	`handlePresence(PresenceHandler.PresenceContext context)`	Handles a change of user presence in a topic.

- Method Detail
  - handlePresence
```
Registration handlePresence(PresenceHandler.PresenceContext context)
```
    Handles a change of user presence in a topic.
    
    Parameters:
    
    context - the context of the user presence, not null
    
    Returns:
    
    a registration that will be removed when the user stops being present