package org.apache.maven.shared.dependency.tree.traversal;
/*
* 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.
*/
import java.util.Stack;
import org.apache.maven.shared.dependency.tree.DependencyNode;
/**
* A dependency node visitor that clones visited nodes into a new dependency tree. This can be used in conjunction with
* a dependency node filter to construct subtrees.
*
* @author <a href="mailto:markhobson@gmail.com">Mark Hobson</a>
* @version $Id: BuildingDependencyNodeVisitor.java 1100703 2011-05-08 08:27:33Z hboutemy $
* @since 1.1
*/
public class BuildingDependencyNodeVisitor
implements DependencyNodeVisitor
{
// fields -----------------------------------------------------------------
/**
* The dependency node visitor to apply on the resultant dependency tree, or <code>null</code> for none.
*/
private final DependencyNodeVisitor visitor;
/**
* The resultant tree parent nodes for the currently visited node.
*/
private final Stack<DependencyNode> parentNodes;
/**
* The root node of the resultant tree.
*/
private DependencyNode rootNode;
// constructors -----------------------------------------------------------
/**
* Creates a dependency node visitor that clones visited nodes into a new dependency tree.
*/
public BuildingDependencyNodeVisitor()
{
this( null );
}
/**
* Creates a dependency node visitor that clones visited nodes into a new dependency tree, and then applies the
* specified dependency node visitor on the resultant dependency tree.
*
* @param visitor
* the dependency node visitor to apply on the resultant dependency tree, or <code>null</code> for none
*/
public BuildingDependencyNodeVisitor( DependencyNodeVisitor visitor )
{
this.visitor = visitor;
parentNodes = new Stack<DependencyNode>();
}
// DependencyNodeVisitor methods ------------------------------------------
/**
* {@inheritDoc}
*/
public boolean visit( DependencyNode node )
{
// clone the node
DependencyNode newNode = new DependencyNode( node.getArtifact(), node.getState(), node.getRelatedArtifact() );
newNode.setOriginalScope( node.getOriginalScope() );
newNode.setFailedUpdateScope( node.getFailedUpdateScope() );
newNode.setPremanagedVersion( node.getPremanagedVersion() );
newNode.setPremanagedScope( node.getPremanagedScope() );
if ( parentNodes.empty() )
{
rootNode = newNode;
}
else
{
DependencyNode parentNode = parentNodes.peek();
parentNode.addChild( newNode );
}
parentNodes.push( newNode );
return true;
}
/**
* {@inheritDoc}
*/
public boolean endVisit( DependencyNode node )
{
parentNodes.pop();
// apply the visitor to the resultant tree on the last visit
if ( parentNodes.empty() && visitor != null )
{
rootNode.accept( visitor );
}
return true;
}
// public methods ---------------------------------------------------------
/**
* Gets the dependency node visitor that this visitor applies on the resultant dependency tree.
*
* @return the dependency node visitor, or <code>null</code> for none
*/
public DependencyNodeVisitor getDependencyNodeVisitor()
{
return visitor;
}
/**
* Gets the root node of the resultant dependency tree constructed by this visitor.
*
* @return the root node, or <code>null</code> if the source tree has not yet been visited
*/
public DependencyNode getDependencyTree()
{
return rootNode;
}
}