/**
* Copyright 2010 Google Inc.
*
* Licensed 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.operation.testing.reference;
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.algorithm.OperationNormalizer;
import org.waveprotocol.wave.model.document.operation.impl.DocOpBuffer;
/**
* A utility class for decomposing operations into an insertion operation, a
* structure-preserving operation, and a deletion operation.
*
* @author Alexandre Mah
*/
final class Decomposer {
/**
* A decomposition consisting of an insertion operation, a
* structure-preserving operation, and a deletion operation.
*/
static final class Decomposition {
final DocOp insertion;
final DocOp preservation;
final DocOp deletion;
Decomposition(DocOp insertion, DocOp preservation, DocOp deletion) {
this.insertion = insertion;
this.preservation = preservation;
this.deletion = deletion;
}
}
private static final class Target
implements EvaluatingDocOpCursor<Decomposition> {
private final EvaluatingDocOpCursor<DocOp> insertionOp =
OperationNormalizer.createNormalizer(new DocOpBuffer());
private final EvaluatingDocOpCursor<DocOp> preservationOp =
OperationNormalizer.createNormalizer(new DocOpBuffer());
private final EvaluatingDocOpCursor<DocOp> deletionOp =
OperationNormalizer.createNormalizer(new DocOpBuffer());
@Override
public Decomposition finish() {
return new Decomposition(insertionOp.finish(), preservationOp.finish(), deletionOp.finish());
}
@Override
public void retain(int itemCount) {
insertionOp.retain(itemCount);
preservationOp.retain(itemCount);
deletionOp.retain(itemCount);
}
@Override
public void characters(String chars) {
insertionOp.characters(chars);
preservationOp.retain(chars.length());
deletionOp.retain(chars.length());
}
@Override
public void elementStart(String type, Attributes attrs) {
insertionOp.elementStart(type, attrs);
preservationOp.retain(1);
deletionOp.retain(1);
}
@Override
public void elementEnd() {
insertionOp.elementEnd();
preservationOp.retain(1);
deletionOp.retain(1);
}
@Override
public void deleteCharacters(String chars) {
insertionOp.retain(chars.length());
preservationOp.retain(chars.length());
deletionOp.deleteCharacters(chars);
}
@Override
public void deleteElementStart(String type, Attributes attrs) {
insertionOp.retain(1);
preservationOp.retain(1);
deletionOp.deleteElementStart(type, attrs);
}
@Override
public void deleteElementEnd() {
insertionOp.retain(1);
preservationOp.retain(1);
deletionOp.deleteElementEnd();
}
@Override
public void replaceAttributes(Attributes oldAttrs, Attributes newAttrs) {
insertionOp.retain(1);
preservationOp.replaceAttributes(oldAttrs, newAttrs);
deletionOp.retain(1);
}
@Override
public void updateAttributes(AttributesUpdate attrUpdate) {
insertionOp.retain(1);
preservationOp.updateAttributes(attrUpdate);
deletionOp.retain(1);
}
@Override
public void annotationBoundary(AnnotationBoundaryMap map) {
preservationOp.annotationBoundary(map);
}
}
/**
* Decomposes an operation into an insertion operation, a structure-preserving
* operation, and a deletion operation.
*
* @param op the operation to decompose
* @return the decomposition of the given operation
*/
static Decomposition decompose(DocOp op) {
Target target = new Target();
op.apply(target);
return target.finish();
}
}