001/*
002 * ModeShape (http://www.modeshape.org)
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *       http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016package org.modeshape.schematic.internal.delta;
017
018import org.modeshape.schematic.document.Path;
019import org.modeshape.schematic.internal.document.MutableArray;
020import org.modeshape.schematic.internal.document.MutableDocument;
021
022/**
023 * An atomic array add operation for SchematicValueDelta.
024 * 
025 * @author Randall Hauch <rhauch@redhat.com> (C) 2011 Red Hat Inc.
026 */
027public class AddValueIfAbsentOperation extends AddValueOperation {
028
029    protected transient boolean added;
030
031    public AddValueIfAbsentOperation( Path path,
032                                      Object value ) {
033        super(path, value);
034    }
035
036    public boolean isAdded() {
037        return added;
038    }
039
040    @Override
041    public void rollback( MutableDocument delegate ) {
042        if (added) {
043            MutableArray array = mutableParent(delegate);
044            array.remove(this.index);
045        }
046    }
047
048    @Override
049    public void replay( MutableDocument delegate ) {
050        MutableArray array = mutableParent(delegate);
051        added = array.addValueIfAbsent(value);
052    }
053
054    @Override
055    public String toString() {
056        return super.toString() + " if absent";
057    }
058
059    @Override
060    public int hashCode() {
061        return super.hashCode();
062    }
063
064    @Override
065    public boolean equals( Object obj ) {
066        if (obj instanceof AddValueIfAbsentOperation) {
067            AddValueIfAbsentOperation other = (AddValueIfAbsentOperation)obj;
068            return equalsIfNotNull(value, other.value) && index == other.index
069                   && equalsIfNotNull(getParentPath(), other.getParentPath());
070
071        }
072        return false;
073    }
074}