android/guava/src/com/google/common/graph/AbstractGraphBuilder.java

/*
 * Copyright (C) 2016 The Guava Authors
 *
 * 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 com.google.common.graph;

import com.google.common.base.Optional;

/**
 * A base class for builders that construct graphs with user-defined properties.
 *
 * @author James Sexton
 */
abstract class AbstractGraphBuilder<N> {
  final boolean directed;
  boolean allowsSelfLoops = false;
  ElementOrder<N> nodeOrder = ElementOrder.insertion();
  Optional<Integer> expectedNodeCount = Optional.absent();

  /**
   * Creates a new instance with the specified edge directionality.
   *
   * @param directed if true, creates an instance for graphs whose edges are each directed; if
   *     false, creates an instance for graphs whose edges are each undirected.
   */
  AbstractGraphBuilder(boolean directed) {
    this.directed = directed;
  }
}