/**
* Copyright 2010 JBoss Inc
*
* Licensed 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.drools.eclipse.editors.rete.model;
import org.drools.reteoo.BaseVertex;
/**
* A connection between two distinct vertices.
*/
public class Connection extends ModelElement {
private boolean isConnected;
private BaseVertex source;
private BaseVertex target;
/**
* Creating a connection between two distinct vertices.
*
* @param source a source endpoint
* @param target a target endpoint
* @throws IllegalArgumentException if any of the parameters are null or source == target
*/
public Connection(BaseVertex source,
BaseVertex target) {
this.source = source;
this.target = target;
source.addConnection( this );
target.addConnection( this );
isConnected = true;
}
/**
* Disconnect this connection from the vertices it is attached to.
*/
public void disconnect() {
if ( isConnected ) {
source.removeConnection( this );
target.removeConnection( this );
isConnected = false;
}
}
/**
* Returns the source endpoint of this connection.
*
* @return BaseVertex vertex
*/
public BaseVertex getSource() {
return source;
}
/**
* Returns the target endpoint of this connection.
*
* @return BaseVertex vertex
*/
public BaseVertex getTarget() {
return target;
}
/**
* Gets opposite of specified vertex.
*
* Returning <code>null</code> if specified not does not belong into this connection.
*
* @param vertex
* @return opposite of vertex
*/
public BaseVertex getOpposite(BaseVertex vertex) {
// If null or not part of this connection
if ( vertex == null || (!vertex.equals( getSource() ) && !vertex.equals( getTarget() )) ) {
return null;
}
if ( vertex.equals( getSource() ) ) {
return getTarget();
}
return getSource();
}
}