GWT 2.1.1

com.google.gwt.event.shared
Class SimpleEventBus

java.lang.Object
  extended by com.google.gwt.event.shared.EventBus
      extended by com.google.gwt.event.shared.SimpleEventBus
All Implemented Interfaces:
HasHandlers

public class SimpleEventBus
extends EventBus

Basic implementation of EventBus.


Constructor Summary
SimpleEventBus()
           
 
Method Summary
<H extends EventHandler>
HandlerRegistration
addHandler(GwtEvent.Type<H> type, H handler)
          Adds an unfiltered handler to receive events of this type from all sources.
<H extends EventHandler>
HandlerRegistration
addHandlerToSource(GwtEvent.Type<H> type, java.lang.Object source, H handler)
          Adds a handler to receive events of this type from the given source.
 void fireEvent(GwtEvent<?> event)
          Fires the event from no source.
 void fireEventFromSource(GwtEvent<?> event, java.lang.Object source)
          Fires the given event to the handlers listening to the event's type.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

SimpleEventBus

public SimpleEventBus()
Method Detail

addHandler

public <H extends EventHandler> HandlerRegistration addHandler(GwtEvent.Type<H> type,
                                                               H handler)
Description copied from class: EventBus
Adds an unfiltered handler to receive events of this type from all sources.

It is rare to call this method directly. More typically a GwtEvent subclass will provide a static register method, or a widget will accept handlers directly.

A tip: to make a handler de-register itself, the following works:

new MyHandler() {
  HandlerRegistration reg = MyEvent.register(eventBus, this);
 
  public void onMyThing(MyEvent event) {
    /* do your thing */
    reg.removeHandler();
  }
 };
 

Specified by:
addHandler in class EventBus
Type Parameters:
H - The type of handler
Parameters:
type - the event type associated with this handler
handler - the handler
Returns:
the handler registration, can be stored in order to remove the handler later

addHandlerToSource

public <H extends EventHandler> HandlerRegistration addHandlerToSource(GwtEvent.Type<H> type,
                                                                       java.lang.Object source,
                                                                       H handler)
Description copied from class: EventBus
Adds a handler to receive events of this type from the given source.

It is rare to call this method directly. More typically a GwtEvent subclass will provide a static register method, or a widget will accept handlers directly.

Specified by:
addHandlerToSource in class EventBus
Type Parameters:
H - The type of handler
Parameters:
type - the event type associated with this handler
source - the source associated with this handler
handler - the handler
Returns:
the handler registration, can be stored in order to remove the handler later

fireEvent

public void fireEvent(GwtEvent<?> event)
Description copied from class: EventBus
Fires the event from no source. Only unfiltered handlers will receive it.

Specified by:
fireEvent in interface HasHandlers
Specified by:
fireEvent in class EventBus
Parameters:
event - the event to fire

fireEventFromSource

public void fireEventFromSource(GwtEvent<?> event,
                                java.lang.Object source)
Description copied from class: EventBus
Fires the given event to the handlers listening to the event's type.

Any exceptions thrown by handlers will be bundled into a UmbrellaException and then re-thrown after all handlers have completed. An exception thrown by a handler will not prevent other handlers from executing.

Specified by:
fireEventFromSource in class EventBus
Parameters:
event - the event to fire

GWT 2.1.1