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.HashCode;
020import org.modeshape.schematic.internal.document.MutableArray;
021import org.modeshape.schematic.internal.document.MutableDocument;
022
023/**
024 * An atomic array add operation for SchematicValueDelta.
025 * 
026 * @author Randall Hauch <rhauch@redhat.com> (C) 2011 Red Hat Inc.
027 */
028public class AddValueOperation extends ArrayOperation {
029
030    protected static final int APPEND_INDEX = -1;
031
032    protected final Object value;
033    protected final int index;
034    protected transient int actualIndex = -1;
035
036    public AddValueOperation( Path path,
037                              Object value ) {
038        super(path, HashCode.compute(path, value, APPEND_INDEX));
039        assert value != null;
040        this.value = value;
041        this.index = APPEND_INDEX;
042    }
043
044    public AddValueOperation( Path path,
045                              Object value,
046                              int index ) {
047        super(path, HashCode.compute(path, value, index));
048        assert value != null;
049        this.value = value;
050        this.index = index;
051    }
052
053    @Override
054    public AddValueOperation clone() {
055        return new AddValueOperation(getParentPath(), cloneValue(value), index);
056    }
057
058    public Object getValue() {
059        return value;
060    }
061
062    public int getIndex() {
063        return index;
064    }
065
066    public int getActualIndex() {
067        return actualIndex;
068    }
069
070    @Override
071    public void rollback( MutableDocument delegate ) {
072        if (actualIndex > -1) {
073            MutableArray array = mutableParent(delegate);
074            array.remove(actualIndex);
075        }
076    }
077
078    @Override
079    public void replay( MutableDocument delegate ) {
080        MutableArray array = mutableParent(delegate);
081        if (index == APPEND_INDEX) {
082            actualIndex = array.addValue(value);
083        } else {
084            array.addValue(index, value);
085            actualIndex = index;
086        }
087    }
088
089    @Override
090    public String toString() {
091        return "Add to '" + parentPath + "' the value '" + value + "'" + (index >= 0 ? " at index " + index : "");
092    }
093
094    @Override
095    public int hashCode() {
096        return super.hashCode();
097    }
098
099    @Override
100    public boolean equals( Object obj ) {
101        if (obj instanceof AddValueOperation) {
102            AddValueOperation other = (AddValueOperation)obj;
103            return equalsIfNotNull(value, other.value) && index == other.index
104                   && equalsIfNotNull(getParentPath(), other.getParentPath());
105
106        }
107        return false;
108    }
109}