| package org.eclipse.aether.util.graph.visitor; |
| |
| /* |
| * 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 org.eclipse.aether.graph.DependencyFilter; |
| import org.eclipse.aether.graph.DependencyNode; |
| import org.eclipse.aether.graph.DependencyVisitor; |
| |
| /** |
| * A dependency visitor that delegates to another visitor if nodes match a filter. Note that in case of a mismatching |
| * node, the children of that node are still visisted and presented to the filter. |
| */ |
| public final class FilteringDependencyVisitor |
| implements DependencyVisitor |
| { |
| |
| private final DependencyFilter filter; |
| |
| private final DependencyVisitor visitor; |
| |
| private final Stack<Boolean> accepts; |
| |
| private final Stack<DependencyNode> parents; |
| |
| /** |
| * Creates a new visitor that delegates traversal of nodes matching the given filter to the specified visitor. |
| * |
| * @param visitor The visitor to delegate to, must not be {@code null}. |
| * @param filter The filter to apply, may be {@code null} to not filter. |
| */ |
| public FilteringDependencyVisitor( DependencyVisitor visitor, DependencyFilter filter ) |
| { |
| if ( visitor == null ) |
| { |
| throw new IllegalArgumentException( "dependency visitor not specified" ); |
| } |
| this.visitor = visitor; |
| this.filter = filter; |
| this.accepts = new Stack<Boolean>(); |
| this.parents = new Stack<DependencyNode>(); |
| } |
| |
| /** |
| * Gets the visitor to which this visitor delegates to. |
| * |
| * @return The visitor being delegated to, never {@code null}. |
| */ |
| public DependencyVisitor getVisitor() |
| { |
| return visitor; |
| } |
| |
| /** |
| * Gets the filter being applied before delegation. |
| * |
| * @return The filter being applied or {@code null} if none. |
| */ |
| public DependencyFilter getFilter() |
| { |
| return filter; |
| } |
| |
| public boolean visitEnter( DependencyNode node ) |
| { |
| boolean accept = filter == null || filter.accept( node, parents ); |
| |
| accepts.push( accept ); |
| |
| parents.push( node ); |
| |
| if ( accept ) |
| { |
| return visitor.visitEnter( node ); |
| } |
| else |
| { |
| return true; |
| } |
| } |
| |
| public boolean visitLeave( DependencyNode node ) |
| { |
| parents.pop(); |
| |
| Boolean accept = accepts.pop(); |
| |
| if ( accept ) |
| { |
| return visitor.visitLeave( node ); |
| } |
| else |
| { |
| return true; |
| } |
| } |
| |
| } |