javafx.event.Event Maven / Gradle / Ivy
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package javafx.event;
import java.util.EventObject;
import com.sun.javafx.event.EventUtil;
import java.io.IOException;
import javafx.beans.NamedArg;
// PENDING_DOC_REVIEW
/**
* Base class for FX events. Each FX event has associated an event source,
* event target and an event type. The event source specifies for an event
* handler the object on which that handler has been registered and which sent
* the event to it. The event target defines the path through which the event
* will travel when posted. The event type provides additional classification
* to events of the same {@code Event} class.
* @since JavaFX 2.0
*/
public class Event extends EventObject implements Cloneable {
private static final long serialVersionUID = 20121107L;
/**
* The constant which represents an unknown event source / target.
*/
public static final EventTarget NULL_SOURCE_TARGET = tail -> tail;
/**
* Common supertype for all event types.
*/
public static final EventType ANY = EventType.ROOT;
/**
* Type of the event.
*/
protected EventType eventType;
/**
* Event target that defines the path through which the event
* will travel when posted.
*/
protected transient EventTarget target;
/**
* Whether this event has been consumed by any filter or handler.
*/
protected boolean consumed;
/**
* Construct a new {@code Event} with the specified event type. The source
* and target of the event is set to {@code NULL_SOURCE_TARGET}.
*
* @param eventType the event type
*/
public Event(final @NamedArg("eventType") EventType eventType) {
this(null, null, eventType);
}
/**
* Construct a new {@code Event} with the specified event source, target
* and type. If the source or target is set to {@code null}, it is replaced
* by the {@code NULL_SOURCE_TARGET} value.
*
* @param source the event source which sent the event
* @param target the event target to associate with the event
* @param eventType the event type
*/
public Event(final @NamedArg("source") Object source,
final @NamedArg("target") EventTarget target,
final @NamedArg("eventType") EventType eventType) {
super((source != null) ? source : NULL_SOURCE_TARGET);
this.target = (target != null) ? target : NULL_SOURCE_TARGET;
this.eventType = eventType;
}
/**
* Returns the event target of this event. The event target specifies
* the path through which the event will travel when posted.
*
* @return the event target
*/
public EventTarget getTarget() {
return target;
}
/**
* Gets the event type of this event. Objects of the same {@code Event}
* class can have different event types. These event types further specify
* what kind of event occurred.
*
* @return the event type
*/
public EventType getEventType() {
return eventType;
}
/**
* Creates and returns a copy of this event with the specified event source
* and target. If the source or target is set to {@code null}, it is
* replaced by the {@code NULL_SOURCE_TARGET} value.
*
* @param newSource the new source of the copied event
* @param newTarget the new target of the copied event
* @return the event copy with the new source and target
*/
public Event copyFor(final Object newSource, final EventTarget newTarget) {
final Event newEvent = (Event) clone();
newEvent.source = (newSource != null) ? newSource : NULL_SOURCE_TARGET;
newEvent.target = (newTarget != null) ? newTarget : NULL_SOURCE_TARGET;
newEvent.consumed = false;
return newEvent;
}
/**
* Indicates whether this {@code Event} has been consumed by any filter or
* handler.
*
* @return {@code true} if this {@code Event} has been consumed,
* {@code false} otherwise
*/
public boolean isConsumed() {
return consumed;
}
/**
* Marks this {@code Event} as consumed. This stops its further propagation.
*/
public void consume() {
consumed = true;
}
/**
* Creates and returns a copy of this {@code Event}.
* @return a new instance of {@code Event} with all values copied from
* this {@code Event}.
*/
@Override
public Object clone() {
try {
return super.clone();
} catch (final CloneNotSupportedException e) {
// we implement Cloneable, this shouldn't happen
throw new RuntimeException("Can't clone Event");
}
}
@SuppressWarnings("doclint:missing")
private void readObject(java.io.ObjectInputStream in) throws IOException, ClassNotFoundException {
in.defaultReadObject();
source = NULL_SOURCE_TARGET;
target = NULL_SOURCE_TARGET;
}
// PENDING_DOC_REVIEW
/**
* Fires the specified event. The given event target specifies the path
* through which the event will travel.
*
* @param eventTarget the target for the event
* @param event the event to fire
* @throws NullPointerException if eventTarget or event is null
*/
public static void fireEvent(EventTarget eventTarget, Event event) {
if (eventTarget == null) {
throw new NullPointerException("Event target must not be null!");
}
if (event == null) {
throw new NullPointerException("Event must not be null!");
}
EventUtil.fireEvent(eventTarget, event);
}
}
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