001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.vfs2;
018
019import java.util.Objects;
020
021/**
022 * Inverts file inclusion of a delegate FileSelector, folder traversal is delegated.
023 *
024 * @since 2.2
025 */
026public class InvertIncludeFileSelector implements FileSelector {
027
028    private final FileSelector delegateFileSelector;
029
030    /**
031     * Constructs a new instance.
032     *
033     * @param delegateFileSelector Delegate to this FileSelector.
034     */
035    public InvertIncludeFileSelector(final FileSelector delegateFileSelector) {
036        this.delegateFileSelector = Objects.requireNonNull(delegateFileSelector, "delegateFileSelector");
037    }
038
039    /**
040     * Inverts the result of calling {@link #includeFile(FileSelectInfo)} on the delegate.
041     */
042    @Override
043    public boolean includeFile(final FileSelectInfo fileInfo) throws Exception {
044        return !delegateFileSelector.includeFile(fileInfo);
045    }
046
047    /**
048     * Calls {@link #traverseDescendents(FileSelectInfo)} on the delegate.
049     */
050    @Override
051    public boolean traverseDescendents(final FileSelectInfo fileInfo) throws Exception {
052        return delegateFileSelector.traverseDescendants(fileInfo);
053    }
054
055}