com.google.gwt.event.shared

Class GwtEvent<H extends EventHandler>

java.lang.Object

com.google.web.bindery.event.shared.Event<H>

com.google.gwt.event.shared.GwtEvent<H>

Type Parameters:

H - handler type

Direct Known Subclasses:

AbstractHasData.RedrawEvent, AttachEvent, BeforeSelectionEvent, CellPreviewEvent, CloseEvent, ColumnSortEvent, DomEvent, Event.NativePreviewEvent, FormPanel.SubmitCompleteEvent, FormPanel.SubmitEvent, HighlightEvent, InitializeEvent, LoadingStateChangeEvent, OpenEvent, PlaceChangeEvent, PlaceChangeRequestEvent, RangeChangeEvent, ResizeEvent, RowCountChangeEvent, RowHoverEvent, SelectionChangeEvent, SelectionEvent, ShowRangeEvent, ValueChangeEvent, Window.ClosingEvent, Window.ScrollEvent

public abstract class GwtEvent<H extends EventHandler>
extends Event<H>

Root of all GWT widget and dom events sourced by a HandlerManager. All GWT events are considered dead and should no longer be accessed once the HandlerManager which originally fired the event finishes with it. That is, don't hold on to event objects outside of your handler methods.

There is no need for an application's custom event types to extend GwtEvent. Prefer Event instead.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	GwtEvent.Type<H> Type class used to register events with the HandlerManager.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	GwtEvent() Constructor.

Method Summary

Modifier and Type	Method and Description
protected void	assertLive() Asserts that the event still should be accessed.
protected abstract void	dispatch(H handler) Should only be called by HandlerManager.
abstract GwtEvent.Type<H>	getAssociatedType() Returns the Event.Type used to register this event, allowing an EventBus to find handlers of the appropriate class.
java.lang.Object	getSource() Returns the source for this event.
protected boolean	isLive() Is the event current live?
protected void	kill() Kill the event.
(package private) void	overrideSource(java.lang.Object source)
protected void	revive() Revives the event.

Methods inherited from class com.google.web.bindery.event.shared.Event

setSource, toDebugString, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

GwtEvent

protected GwtEvent()

Constructor.

Method Detail

getAssociatedType

public abstract GwtEvent.Type<H> getAssociatedType()

Description copied from class: Event

Returns the Event.Type used to register this event, allowing an EventBus to find handlers of the appropriate class.

Specified by:

getAssociatedType in class Event<H extends EventHandler>

Returns:

the type

getSource

public java.lang.Object getSource()

Description copied from class: Event

Returns the source for this event. The type and meaning of the source is arbitrary, and is most useful as a secondary key for handler registration. (See EventBus.addHandlerToSource(com.google.web.bindery.event.shared.Event.Type<H>, java.lang.Object, H), which allows a handler to register for events of a particular type, tied to a particular source.)

Note that the source is actually set at dispatch time, e.g. via EventBus.fireEventFromSource(Event, Object).

Overrides:

getSource in class Event<H extends EventHandler>

Returns:

object representing the source of this event

assertLive

protected void assertLive()

Asserts that the event still should be accessed. All events are considered to be "dead" after their original handler manager finishes firing them. An event can be revived by calling revive().

dispatch

protected abstract void dispatch(H handler)

Should only be called by HandlerManager. In other words, do not use or call.

Specified by:

dispatch in class Event<H extends EventHandler>

Parameters:

handler - handler

See Also:

EventBus.dispatchEvent(Event, Object)

isLive

protected final boolean isLive()

Is the event current live?

Returns:

whether the event is live

kill

protected void kill()

Kill the event. After the event has been killed, users cannot really on its values or functions being available.

revive

protected void revive()

Revives the event. Used when recycling event instances.

overrideSource

void overrideSource(java.lang.Object source)