com.sun.javafx.event.BasicEventDispatcher Maven / Gradle / Ivy
/*
* Copyright (c) 2011, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package com.sun.javafx.event;
import javafx.event.Event;
import javafx.event.EventDispatchChain;
import javafx.event.EventDispatcher;
/**
* Event dispatcher which introduces event dispatch phase specific methods -
* {@code dispatchCapturingEvent} and {@code dispatchBubblingEvent}. These
* are used in the {@code BasicEventDispatcher.dispatchEvent} implementation,
* but because they are public they can be called directly as well. Their
* default implementation does nothing and is expected to be overridden in
* subclasses. The {@code BasicEventDispatcher} also adds possibility to chain
* event dispatchers. This is used together with the direct access to the phase
* specific dispatch methods to implement {@code CompositeEventDispatcher}.
*
* An event dispatcher derived from {@code BasicEventDispatcher} can act as
* a standalone event dispatcher or can be used to form a dispatch chain in
* {@code CompositeEventDispatcher}.
*/
public abstract class BasicEventDispatcher implements EventDispatcher {
private BasicEventDispatcher previousDispatcher;
private BasicEventDispatcher nextDispatcher;
@Override
public Event dispatchEvent(Event event, final EventDispatchChain tail) {
event = dispatchCapturingEvent(event);
if (event.isConsumed()) {
return null;
}
event = tail.dispatchEvent(event);
if (event != null) {
event = dispatchBubblingEvent(event);
if (event.isConsumed()) {
return null;
}
}
return event;
}
public Event dispatchCapturingEvent(Event event) {
return event;
}
public Event dispatchBubblingEvent(Event event) {
return event;
}
public final BasicEventDispatcher getPreviousDispatcher() {
return previousDispatcher;
}
public final BasicEventDispatcher getNextDispatcher() {
return nextDispatcher;
}
public final void insertNextDispatcher(
final BasicEventDispatcher newDispatcher) {
if (nextDispatcher != null) {
nextDispatcher.previousDispatcher = newDispatcher;
}
newDispatcher.nextDispatcher = nextDispatcher;
newDispatcher.previousDispatcher = this;
nextDispatcher = newDispatcher;
}
}