code: /**
   * This file is part of Eclipse Steady.
   *
   * 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.
   *
   * SPDX-License-Identifier: Apache-2.0
   * SPDX-FileCopyrightText: Copyright (c) 2018-2020 SAP SE or an SAP affiliate company and Eclipse Steady contributors
   */
  package org.eclipse.steady.shared.enums;
  
  import org.eclipse.steady.shared.json.model.ConstructId;
  
  /**
   * Defines the type of modification of a given {@link ConstructId}.
   *
   * Change types {@link ConstructChangeType#ADD}, {@link ConstructChangeType#MOD} and {@link ConstructChangeType#DEL}
   * apply both in the context of a single commit and multiple commits, whereas {@link ConstructChangeType#NUL} is only
   * meaningful in the context of multiple commits.
   *
   * When used in the context of multiple commits, the {@link ConstructChangeType} indicates the overall modification done over the
   * course of the ordered commits.
   *
   * {@link ConstructChangeType#ADD} means that the construct has been added,
   * {@link ConstructChangeType#MOD} means it has been modified,
   * {@link ConstructChangeType#DEL} means it has been deleted, and
   * {@link ConstructChangeType#NUL} means that the overall change is null, which happens when
   * the construct has been deleted in an early commit and added in a later commit (or vice-versa).
   */
  public enum ConstructChangeType {
    ADD((byte) 10),
    MOD((byte) 20),
    DEL((byte) 30),
    NUL((byte) 40);
    private byte value;
  
    private ConstructChangeType(byte _value) {
      this.value = _value;
    }
    /**
     * <p>toString.</p>
     *
     * @return a {@link java.lang.String} object.
     */
    public String toString() {
      if (this.value == 10) return "ADD";
      else if (this.value == 20) return "MOD";
      else if (this.value == 30) return "DEL";
      else if (this.value == 40) return "NUL";
      else
        throw new IllegalArgumentException(
            "[" + this.value + "] is not a valid construct change type");
    }
  }
  