Class ForwardingGraph<N>

All Implemented Interfaces:
BaseGraph<N>, Graph<N>, PredecessorsFunction<N>, SuccessorsFunction<N>
Direct Known Subclasses:
Graphs.TransposedGraph, ImmutableGraph, StandardMutableGraph

abstract class ForwardingGraph<N> extends AbstractGraph<N>
A class to allow Graph implementations to be backed by a BaseGraph. This is not currently planned to be released as a general-purpose forwarding class.
  • Constructor Details

    • ForwardingGraph

      ForwardingGraph()
  • Method Details

    • delegate

      abstract BaseGraph<N> delegate()
    • nodes

      public Set<N> nodes()
      Description copied from interface: Graph
      Returns all nodes in this graph, in the order specified by Graph.nodeOrder().
    • edgeCount

      protected long edgeCount()
      Defer to AbstractBaseGraph.edges() (based on successors(Object)) for full edges() implementation.
      Overrides:
      edgeCount in class AbstractBaseGraph<N>
    • isDirected

      public boolean isDirected()
      Description copied from interface: Graph
      Returns true if the edges in this graph are directed. Directed edges connect a source node to a target node, while undirected edges connect a pair of nodes to each other.
    • allowsSelfLoops

      public boolean allowsSelfLoops()
      Description copied from interface: Graph
      Returns true if this graph allows self-loops (edges that connect a node to itself). Attempting to add a self-loop to a graph that does not allow them will throw an IllegalArgumentException.
    • nodeOrder

      public ElementOrder<N> nodeOrder()
      Description copied from interface: Graph
      Returns the order of iteration for the elements of Graph.nodes().
    • incidentEdgeOrder

      public ElementOrder<N> incidentEdgeOrder()
      Description copied from interface: BaseGraph
      Specified by:
      incidentEdgeOrder in interface BaseGraph<N>
      Specified by:
      incidentEdgeOrder in interface Graph<N>
      Overrides:
      incidentEdgeOrder in class AbstractBaseGraph<N>
    • adjacentNodes

      public Set<N> adjacentNodes(N node)
      Description copied from interface: Graph
      Returns a live view of the nodes which have an incident edge in common with node in this graph.

      This is equal to the union of Graph.predecessors(Object) and Graph.successors(Object).

      If node is removed from the graph after this method is called, the Set view returned by this method will be invalidated, and will throw IllegalStateException if it is accessed in any way, with the following exceptions:

      • view.equals(view) evaluates to true (but any other `equals()` expression involving view will throw)
      • hashCode() does not throw
      • if node is re-added to the graph after having been removed, view's behavior is undefined
    • predecessors

      public Set<N> predecessors(N node)
      Description copied from interface: Graph
      Returns a live view of all nodes in this graph adjacent to node which can be reached by traversing node's incoming edges against the direction (if any) of the edge.

      In an undirected graph, this is equivalent to Graph.adjacentNodes(Object).

      If node is removed from the graph after this method is called, the Set view returned by this method will be invalidated, and will throw IllegalStateException if it is accessed in any way, with the following exceptions:

      • view.equals(view) evaluates to true (but any other `equals()` expression involving view will throw)
      • hashCode() does not throw
      • if node is re-added to the graph after having been removed, view's behavior is undefined
    • successors

      public Set<N> successors(N node)
      Description copied from interface: Graph
      Returns a live view of all nodes in this graph adjacent to node which can be reached by traversing node's outgoing edges in the direction (if any) of the edge.

      In an undirected graph, this is equivalent to Graph.adjacentNodes(Object).

      This is not the same as "all nodes reachable from node by following outgoing edges". For that functionality, see Graphs.reachableNodes(Graph, Object).

      If node is removed from the graph after this method is called, the Set view returned by this method will be invalidated, and will throw IllegalStateException if it is accessed in any way, with the following exceptions:

      • view.equals(view) evaluates to true (but any other `equals()` expression involving view will throw)
      • hashCode() does not throw
      • if node is re-added to the graph after having been removed, view's behavior is undefined
    • incidentEdges

      public Set<EndpointPair<N>> incidentEdges(N node)
      Description copied from interface: BaseGraph
      Returns a live view of the edges in this graph whose endpoints include node.

      This is equal to the union of incoming and outgoing edges.

      If node is removed from the graph after this method is called, the Set view returned by this method will be invalidated, and will throw IllegalStateException if it is accessed in any way, with the following exceptions:

      • view.equals(view) evaluates to true (but any other `equals()` expression involving view will throw)
      • hashCode() does not throw
      • if node is re-added to the graph after having been removed, view's behavior is undefined
      Specified by:
      incidentEdges in interface BaseGraph<N>
      Specified by:
      incidentEdges in interface Graph<N>
      Overrides:
      incidentEdges in class AbstractBaseGraph<N>
    • degree

      public int degree(N node)
      Description copied from interface: BaseGraph
      Returns the count of node's incident edges, counting self-loops twice (equivalently, the number of times an edge touches node).

      For directed graphs, this is equal to inDegree(node) + outDegree(node).

      For undirected graphs, this is equal to incidentEdges(node).size() + (number of self-loops incident to node).

      If the count is greater than Integer.MAX_VALUE, returns Integer.MAX_VALUE.

      Specified by:
      degree in interface BaseGraph<N>
      Specified by:
      degree in interface Graph<N>
      Overrides:
      degree in class AbstractBaseGraph<N>
    • inDegree

      public int inDegree(N node)
      Description copied from interface: BaseGraph
      Returns the count of node's incoming edges (equal to predecessors(node).size()) in a directed graph. In an undirected graph, returns the BaseGraph.degree(Object).

      If the count is greater than Integer.MAX_VALUE, returns Integer.MAX_VALUE.

      Specified by:
      inDegree in interface BaseGraph<N>
      Specified by:
      inDegree in interface Graph<N>
      Overrides:
      inDegree in class AbstractBaseGraph<N>
    • outDegree

      public int outDegree(N node)
      Description copied from interface: BaseGraph
      Returns the count of node's outgoing edges (equal to successors(node).size()) in a directed graph. In an undirected graph, returns the BaseGraph.degree(Object).

      If the count is greater than Integer.MAX_VALUE, returns Integer.MAX_VALUE.

      Specified by:
      outDegree in interface BaseGraph<N>
      Specified by:
      outDegree in interface Graph<N>
      Overrides:
      outDegree in class AbstractBaseGraph<N>
    • hasEdgeConnecting

      public boolean hasEdgeConnecting(N nodeU, N nodeV)
      Description copied from interface: BaseGraph
      Returns true if there is an edge that directly connects nodeU to nodeV. This is equivalent to nodes().contains(nodeU) && successors(nodeU).contains(nodeV).

      In an undirected graph, this is equal to hasEdgeConnecting(nodeV, nodeU).

      Specified by:
      hasEdgeConnecting in interface BaseGraph<N>
      Specified by:
      hasEdgeConnecting in interface Graph<N>
      Overrides:
      hasEdgeConnecting in class AbstractBaseGraph<N>
    • hasEdgeConnecting

      public boolean hasEdgeConnecting(EndpointPair<N> endpoints)
      Description copied from interface: BaseGraph
      Returns true if there is an edge that directly connects endpoints (in the order, if any, specified by endpoints). This is equivalent to edges().contains(endpoints).

      Unlike the other EndpointPair-accepting methods, this method does not throw if the endpoints are unordered; it simply returns false. This is for consistency with the behavior of

      invalid reference
      Collection#contains(Object)
      (which does not generally throw if the object cannot be present in the collection), and the desire to have this method's behavior be compatible with edges().contains(endpoints).
      Specified by:
      hasEdgeConnecting in interface BaseGraph<N>
      Specified by:
      hasEdgeConnecting in interface Graph<N>
      Overrides:
      hasEdgeConnecting in class AbstractBaseGraph<N>