/**
* 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.
*/
package org.waveprotocol.wave.model.document.operation.algorithm;
import org.waveprotocol.wave.model.document.operation.AnnotationBoundaryMap;
import org.waveprotocol.wave.model.document.operation.Attributes;
import org.waveprotocol.wave.model.document.operation.AttributesUpdate;
import org.waveprotocol.wave.model.document.operation.DocOp;
import org.waveprotocol.wave.model.document.operation.EvaluatingDocOpCursor;
import org.waveprotocol.wave.model.document.operation.impl.AttributesUpdateImpl;
import org.waveprotocol.wave.model.document.operation.impl.DocOpBuffer;
/**
* A reverser of document operations.
*
* @param <T> the type that the <code>finish()</code> method returns
*/
public final class DocOpInverter<T> implements EvaluatingDocOpCursor<T> {
private final EvaluatingDocOpCursor<T> target;
public DocOpInverter(EvaluatingDocOpCursor<T> target) {
this.target = target;
}
@Override
public T finish() {
return target.finish();
}
@Override
public void retain(int itemCount) {
target.retain(itemCount);
}
@Override
public void characters(String chars) {
target.deleteCharacters(chars);
}
@Override
public void elementStart(String type, Attributes attrs) {
target.deleteElementStart(type, attrs);
}
@Override
public void elementEnd() {
target.deleteElementEnd();
}
@Override
public void deleteCharacters(String chars) {
target.characters(chars);
}
@Override
public void deleteElementStart(String type, Attributes attrs) {
target.elementStart(type, attrs);
}
@Override
public void deleteElementEnd() {
target.elementEnd();
}
@Override
public void replaceAttributes(Attributes oldAttrs, Attributes newAttrs) {
target.replaceAttributes(newAttrs, oldAttrs);
}
@Override
public void updateAttributes(AttributesUpdate attrUpdate) {
AttributesUpdate update = new AttributesUpdateImpl();
// TODO: This is a little silly. We should do this a better way.
for (int i = 0; i < attrUpdate.changeSize(); ++i) {
update = update.composeWith(new AttributesUpdateImpl(attrUpdate.getChangeKey(i),
attrUpdate.getNewValue(i), attrUpdate.getOldValue(i)));
}
target.updateAttributes(update);
}
@Override
public void annotationBoundary(final AnnotationBoundaryMap map) {
// Warning: Performing multiple reversals can cause multiple wrappers to be created.
// TODO: Maybe we should change this so that this issue doesn't occur.
target.annotationBoundary(new AnnotationBoundaryMap() {
@Override
public int changeSize() {
return map.changeSize();
}
@Override
public String getChangeKey(int changeIndex) {
return map.getChangeKey(changeIndex);
}
@Override
public String getOldValue(int changeIndex) {
return map.getNewValue(changeIndex);
}
@Override
public String getNewValue(int changeIndex) {
return map.getOldValue(changeIndex);
}
@Override
public int endSize() {
return map.endSize();
}
@Override
public String getEndKey(int endIndex) {
return map.getEndKey(endIndex);
}
});
}
public static DocOp invert(DocOp input) {
DocOpInverter<DocOp> inverter = new DocOpInverter<DocOp>(new DocOpBuffer());
input.apply(inverter);
return inverter.finish();
}
}