com.vaadin.collaborationengine

Class ComponentConnectionContext

java.lang.Object

com.vaadin.collaborationengine.ComponentConnectionContext

All Implemented Interfaces:

ConnectionContext

public class ComponentConnectionContext
extends Object
implements ConnectionContext

A connection context based on the attach state of a set of component instances. The context is considered active whenever at least one tracked component is attached. All attached components must belong to the same UI instance, and this UI instance is used to dispatch actions using UI.access(Command).

Author:

Vaadin Ltd

Constructor Summary

Constructors

Constructor and Description
ComponentConnectionContext() Creates an empty component connection context.
ComponentConnectionContext(Component component) Creates a new component connection context which is initially using a single component.

Method Summary

Modifier and Type	Method and Description
void	addComponent(Component component) Adds a component instance to track for this context.
<T> CompletableFuture<T>	createCompletableFuture() Gets a completable future that needs to be resolved within the current context.
void	dispatchAction(Command action) Executes the given action by holding the session lock.
void	removeComponent(Component component) Stops tracking a component for this context.
Registration	setActivationHandler(ActivationHandler activationHandler) Sets an instance of ActivationHandler to the current context.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ComponentConnectionContext

public ComponentConnectionContext()

Creates an empty component connection context.

ComponentConnectionContext

public ComponentConnectionContext(Component component)

Creates a new component connection context which is initially using a single component.

Parameters:

component - the component to use, not null

Method Detail

addComponent

public void addComponent(Component component)

Adds a component instance to track for this context. Calling this method again with a component that is already tracked has no effect.

Parameters:

component - the component to track, not null

See Also:

removeComponent(Component)

removeComponent

public void removeComponent(Component component)

Stops tracking a component for this context. Calling this method for a component that isn't tracked has no effect.

Parameters:

component - the component to stop tracking, not null

See Also:

addComponent(Component)

setActivationHandler

public Registration setActivationHandler(ActivationHandler activationHandler)

Description copied from interface: ConnectionContext

Sets an instance of ActivationHandler to the current context. This method should include logic for updating the activation status.

Specified by:

setActivationHandler in interface ConnectionContext

Parameters:

activationHandler - the handler for activation changes

Returns:

the registration for any logic that needs to be cleaned up if the connection is closed permanently, or null if there is nothing to clean up

dispatchAction

public void dispatchAction(Command action)

Executes the given action by holding the session lock. This is done by using UI.access(Command) on the UI that the component(s) associated with this context belong to. This ensures that any UI changes are pushed to the client in real-time if Push is enabled.

If this context is not active (none of the components are attached to a UI), the action is postponed until the connection becomes active.

Specified by:

dispatchAction in interface ConnectionContext

Parameters:

action - the action to dispatch

createCompletableFuture

public <T> CompletableFuture<T> createCompletableFuture()

Description copied from interface: ConnectionContext

Gets a completable future that needs to be resolved within the current context.

Specified by:

createCompletableFuture in interface ConnectionContext

Returns:

the CompletableFuture to be resolved