com.vaadin.flow.component.ComponentEventBus API 10.0.25 | Vaadin

You're viewing an older version of Vaadin JavaDoc. Please see version 24.7.0 for the latest.

com.vaadin.flow.component.

java.lang.Object
- com.vaadin.flow.component.ComponentEventBus

All Implemented Interfaces:

Serializable
```
public class ComponentEventBus
extends Object
implements Serializable
```
An event bus for Components.
Handles adding and removing event listeners, and firing events of type ComponentEvent.
Events can either be fired manually through fireEvent(ComponentEvent) or automatically based on a DOM event (see @DomEvent). Automatically fired events must have a suitable constructor, as defined in DomEvent.

Since:

1.0

Author:

Vaadin Ltd

See Also:

Serialized Form

Constructor Summary

Constructors
Constructor and Description

ComponentEventBus(Component component)
Creates an event bus for the given component.

Method Summary

All Methods
Modifier and Type	Method and Description
`<T extends ComponentEvent<?>> Registration`	`addListener(Class<T> eventType, ComponentEventListener<T> listener)` Adds a listener for the given event type.
`void`	`fireEvent(ComponentEvent event)` Dispatches the event to all listeners registered for the event type.
`boolean`	`hasListener(Class<? extends ComponentEvent> eventType)` Checks if there is at least one listener registered for the given event type.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - ComponentEventBus
```
public ComponentEventBus(Component component)
```
    Creates an event bus for the given component.
    
    Parameters:
    
    component - the component which will be used as a source for all fired events
- Method Detail
  - addListener
```
public <T extends ComponentEvent<?>> Registration addListener(Class<T> eventType,
                                                              ComponentEventListener<T> listener)
```
    Adds a listener for the given event type.
    
    Type Parameters:
    
    T - the event type
    
    Parameters:
    
    eventType - the event type for which to call the listener
    
    listener - the listener to call when the event occurs
    
    Returns:
    
    an object which can be used to remove the event listener
  - hasListener
```
public boolean hasListener(Class<? extends ComponentEvent> eventType)
```
    Checks if there is at least one listener registered for the given event type.
    
    Parameters:
    
    eventType - the component event type
    
    Returns:
    
    true if at least one listener is registered, false otherwise
  - fireEvent
```
public void fireEvent(ComponentEvent event)
```
    Dispatches the event to all listeners registered for the event type.
    
    Parameters:
    
    event - the event to fire