| /* |
| * Copyright (C) 2019 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 java.util.AbstractSet; |
| import java.util.Set; |
| import org.checkerframework.checker.nullness.compatqual.NullableDecl; |
| |
| /** |
| * Abstract base class for an incident edges set that allows different implementations of {@link |
| * AbstractSet#iterator()}. |
| */ |
| abstract class IncidentEdgeSet<N> extends AbstractSet<EndpointPair<N>> { |
| protected final N node; |
| protected final BaseGraph<N> graph; |
| |
| IncidentEdgeSet(BaseGraph<N> graph, N node) { |
| this.graph = graph; |
| this.node = node; |
| } |
| |
| @Override |
| public boolean remove(Object o) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public int size() { |
| if (graph.isDirected()) { |
| return graph.inDegree(node) |
| + graph.outDegree(node) |
| - (graph.successors(node).contains(node) ? 1 : 0); |
| } else { |
| return graph.adjacentNodes(node).size(); |
| } |
| } |
| |
| @Override |
| public boolean contains(@NullableDecl Object obj) { |
| if (!(obj instanceof EndpointPair)) { |
| return false; |
| } |
| EndpointPair<?> endpointPair = (EndpointPair<?>) obj; |
| |
| if (graph.isDirected()) { |
| if (!endpointPair.isOrdered()) { |
| return false; |
| } |
| |
| Object source = endpointPair.source(); |
| Object target = endpointPair.target(); |
| return (node.equals(source) && graph.successors(node).contains(target)) |
| || (node.equals(target) && graph.predecessors(node).contains(source)); |
| } else { |
| if (endpointPair.isOrdered()) { |
| return false; |
| } |
| Set<N> adjacent = graph.adjacentNodes(node); |
| Object nodeU = endpointPair.nodeU(); |
| Object nodeV = endpointPair.nodeV(); |
| |
| return (node.equals(nodeV) && adjacent.contains(nodeU)) |
| || (node.equals(nodeU) && adjacent.contains(nodeV)); |
| } |
| } |
| } |