/**
* Copyright 2008 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.wave;
import org.waveprotocol.wave.model.wave.data.BlipData;
import org.waveprotocol.wave.model.operation.OperationException;
import java.util.Collections;
import java.util.List;
/**
* A wavelet operation that can be inverted.
*
*/
public abstract class InvertibleBlipOperation extends BlipOperation {
protected InvertibleBlipOperation(WaveletOperationContext context) {
super(context);
}
/**
* {@inheritDoc}
*/
@Override
public final List<BlipOperation> applyAndReturnReverse(BlipData target)
throws OperationException {
WaveletOperationContext reverseContext = createReverseContext(target);
doUpdate(target);
doApply(target);
return Collections.singletonList(invert(reverseContext));
}
/**
* @return The inverse of this operation.
*/
protected abstract BlipOperation invert(WaveletOperationContext newContext);
}