CoreNoOp.java

/**
 * 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.operation.core;

import org.waveprotocol.wave.model.wave.data.core.CoreWaveletData;

/**
 * Operation class for a no-op.
 */
public final class CoreNoOp extends CoreWaveletOperation {

  /**
   * The singleton instance.
   */
  public static final CoreNoOp INSTANCE = new CoreNoOp();

  private CoreNoOp() {}

  /**
   * Does nothing.
   */
  @Override
  protected void doApply(CoreWaveletData target) {
    // do nothing.
  }

  @Override
  public CoreWaveletOperation getInverse() {
    return this;
  }

  @Override
  public String toString() {
    return "NoOp()";
  }

}