| 43 | |
| 44 | |
| 45 | @Beta |
| 46 | public final class NetworkBuilder<N, E> { |
| 47 | final boolean directed; |
| 48 | boolean allowsParallelEdges = false; |
| 49 | boolean allowsSelfLoops = true; |
| 50 | |
| 51 | Comparator<N> nodeComparator = null; |
| 52 | |
| 53 | Comparator<E> edgeComparator = null; |
| 54 | |
| 55 | Optional<Integer> expectedNodeCount = Optional.absent(); |
| 56 | |
| 57 | Optional<Integer> expectedEdgeCount = Optional.absent(); |
| 58 | |
| 59 | /** |
| 60 | * Creates a new instance with the specified edge directionality. |
| 61 | * |
| 62 | * @param directed if true, creates an instance for graphs whose edges are each directed; |
| 63 | * if false, creates an instance for graphs whose edges are each undirected. |
| 64 | */ |
| 65 | |
| 66 | |
| 67 | private NetworkBuilder(boolean directed) { |
| 68 | this.directed = directed; |
| 69 | } |
| 70 | |
| 71 | /** |
| 72 | * Returns a {@link NetworkBuilder} for building directed graphs. |
| 73 | */ |
| 74 | |
| 75 | |
| 76 | public static NetworkBuilder<Object, Object> directed() { |
| 77 | return new NetworkBuilder<Object, Object>(true); |
| 78 | } |
| 79 | |
| 80 | /** |
| 81 | * Returns a {@link NetworkBuilder} for building undirected graphs. |
| 82 | */ |
| 83 | |
| 84 | |
| 85 | public static NetworkBuilder<Object, Object> undirected() { |
| 86 | return new NetworkBuilder<Object, Object>(false); |
| 87 | } |
| 88 | |
| 89 | /** |
| 90 | * Returns a {@link NetworkBuilder} initialized with all properties queryable from {@code graph}. |
| 91 | * |
| 92 | * <p>The "queryable" properties are those that are exposed through the {@link Network} interface, |
| 93 | * such as {@link Network#isDirected()}. Other properties, such as |
| 94 | * {@link #expectedNodeCount(int)}, are not set in the new builder. |
| 95 | */ |
| 96 | |
| 97 | |
| 98 | public static <N, E> NetworkBuilder<N, E> from(Network<N, E> graph) { |
| 99 | return new NetworkBuilder<N, E>(graph.isDirected()).allowsParallelEdges(graph.allowsParallelEdges()).allowsSelfLoops(graph.allowsSelfLoops()); |
| 100 | } |
| 101 | |
| 102 | /** |