/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.tinkerpop.gremlin.process.traversal.step.util.event;
import org.apache.tinkerpop.gremlin.process.traversal.Traversal;
import org.apache.tinkerpop.gremlin.structure.Edge;
import org.apache.tinkerpop.gremlin.structure.Element;
import org.apache.tinkerpop.gremlin.structure.Graph;
import org.apache.tinkerpop.gremlin.structure.Property;
import org.apache.tinkerpop.gremlin.structure.Vertex;
import org.apache.tinkerpop.gremlin.structure.VertexProperty;
import java.util.Iterator;
/**
* A representation of some action that occurs on a {@link Graph} for a {@link Traversal}.
*
* @author Stephen Mallette (http://stephen.genoprime.com)
*/
public interface Event {
/**
* An {@code Event} publishes its action to all the event {@link MutationListener} objects.
*/
void fireEvent(final Iterator<MutationListener> eventListeners);
/**
* Represents an action where an {@link Edge} is added to the {@link Graph}.
*/
class EdgeAddedEvent implements Event {
private final Edge edge;
public EdgeAddedEvent(final Edge edge) {
this.edge = edge;
}
@Override
public void fireEvent(final Iterator<MutationListener> eventListeners) {
while (eventListeners.hasNext()) {
eventListeners.next().edgeAdded(edge);
}
}
}
/**
* Represents an action where an {@link Edge} {@link Property} is added/modified. If the {@link Property} is
* new then the {@code oldValue} will be {@code null}.
*/
class EdgePropertyChangedEvent extends ElementPropertyChangedEvent {
public EdgePropertyChangedEvent(final Edge edge, final Property oldValue, final Object newValue) {
super(edge, oldValue, newValue);
}
@Override
void fire(final MutationListener listener, final Element element, final Property oldValue, final Object newValue, final Object... vertexPropertyKeyValues) {
listener.edgePropertyChanged((Edge) element, oldValue, newValue);
}
}
/**
* Represents an action where an {@link Edge} {@link Property} is removed.
*/
class EdgePropertyRemovedEvent extends ElementPropertyEvent {
public EdgePropertyRemovedEvent(final Edge element, final Property removed) {
super(element, removed, null);
}
@Override
void fire(final MutationListener listener, final Element element, final Property oldValue, final Object newValue, final Object... vertexPropertyKeyValues) {
listener.edgePropertyRemoved((Edge) element, oldValue);
}
}
/**
* Represents an action where an {@link Edge} is removed from the {@link Graph}.
*/
class EdgeRemovedEvent implements Event {
private final Edge edge;
public EdgeRemovedEvent(final Edge edge) {
this.edge = edge;
}
@Override
public void fireEvent(final Iterator<MutationListener> eventListeners) {
while (eventListeners.hasNext()) {
eventListeners.next().edgeRemoved(edge);
}
}
}
/**
* Represents an action where a {@link Vertex} is removed from the {@link Graph}.
*/
class VertexAddedEvent implements Event {
private final Vertex vertex;
public VertexAddedEvent(final Vertex vertex) {
this.vertex = vertex;
}
@Override
public void fireEvent(final Iterator<MutationListener> eventListeners) {
while (eventListeners.hasNext()) {
eventListeners.next().vertexAdded(vertex);
}
}
}
/**
* Represents an action where a {@link VertexProperty} is modified on a {@link Vertex}.
*/
class VertexPropertyChangedEvent extends ElementPropertyChangedEvent {
public VertexPropertyChangedEvent(final Vertex element, final Property oldValue, final Object newValue, final Object... vertexPropertyKeyValues) {
super(element, oldValue, newValue, vertexPropertyKeyValues);
}
@Override
void fire(final MutationListener listener, final Element element, final Property oldValue, final Object newValue, final Object... vertexPropertyKeyValues) {
listener.vertexPropertyChanged((Vertex) element, oldValue, newValue, vertexPropertyKeyValues);
}
}
/**
* Represents an action where a {@link Property} is modified on a {@link VertexProperty}.
*/
class VertexPropertyPropertyChangedEvent extends ElementPropertyChangedEvent {
public VertexPropertyPropertyChangedEvent(final VertexProperty element, final Property oldValue, final Object newValue) {
super(element, oldValue, newValue);
}
@Override
void fire(final MutationListener listener, final Element element, final Property oldValue, final Object newValue, final Object... vertexPropertyKeyValues) {
listener.vertexPropertyPropertyChanged((VertexProperty) element, oldValue, newValue);
}
}
/**
* Represents an action where a {@link Property} is removed from a {@link VertexProperty}.
*/
class VertexPropertyPropertyRemovedEvent extends ElementPropertyEvent {
public VertexPropertyPropertyRemovedEvent(final VertexProperty element, final Property removed) {
super(element, removed, null);
}
@Override
void fire(final MutationListener listener, final Element element, final Property oldValue, final Object newValue, final Object... vertexPropertyKeyValues) {
listener.vertexPropertyPropertyRemoved((VertexProperty) element, oldValue);
}
}
/**
* Represents an action where a {@link Property} is removed from a {@link Vertex}.
*/
class VertexPropertyRemovedEvent implements Event {
private final VertexProperty vertexProperty;
public VertexPropertyRemovedEvent(final VertexProperty vertexProperty) {
this.vertexProperty = vertexProperty;
}
@Override
public void fireEvent(final Iterator<MutationListener> eventListeners) {
while (eventListeners.hasNext()) {
eventListeners.next().vertexPropertyRemoved(vertexProperty);
}
}
}
/**
* Represents an action where a {@link Vertex} is removed from the {@link Graph}.
*/
class VertexRemovedEvent implements Event {
private final Vertex vertex;
public VertexRemovedEvent(final Vertex vertex) {
this.vertex = vertex;
}
@Override
public void fireEvent(final Iterator<MutationListener> eventListeners) {
while (eventListeners.hasNext()) {
eventListeners.next().vertexRemoved(vertex);
}
}
}
/**
* A base class for {@link Property} mutation events.
*/
abstract class ElementPropertyChangedEvent extends ElementPropertyEvent {
public ElementPropertyChangedEvent(final Element element, final Property oldValue, final Object newValue, final Object... vertexPropertyKeyValues) {
super(element, oldValue, newValue, vertexPropertyKeyValues);
}
}
/**
* A base class for {@link Property} mutation events.
*/
abstract class ElementPropertyEvent implements Event {
private final Element element;
private final Property oldValue;
private final Object newValue;
private final Object[] vertexPropertyKeyValues;
public ElementPropertyEvent(final Element element, final Property oldValue, final Object newValue, final Object... vertexPropertyKeyValues) {
this.element = element;
this.oldValue = oldValue;
this.newValue = newValue;
this.vertexPropertyKeyValues = vertexPropertyKeyValues;
}
abstract void fire(final MutationListener listener, final Element element, final Property oldValue, final Object newValue, final Object... vertexPropertyKeyValues);
@Override
public void fireEvent(final Iterator<MutationListener> eventListeners) {
while (eventListeners.hasNext()) {
fire(eventListeners.next(), element, oldValue, newValue, vertexPropertyKeyValues);
}
}
}
}