Module org.jgrapht.guava
Package org.jgrapht.graph.guava

Class MutableValueGraphAdapter<V,​W>

  • Type Parameters:
    V - the graph vertex type
    W - the value type
    All Implemented Interfaces:
    java.io.Serializable, java.lang.Cloneable, Graph<V,​com.google.common.graph.EndpointPair<V>>
    Direct Known Subclasses:
    MutableDoubleValueGraphAdapter
    public class MutableValueGraphAdapter<V,​W>
extends BaseValueGraphAdapter<V,​W,​com.google.common.graph.MutableValueGraph<V,​W>>
implements Graph<V,​com.google.common.graph.EndpointPair<V>>, java.lang.Cloneable, java.io.Serializable
    A graph adapter class using Guava's MutableValueGraph.

    The adapter uses class EndpointPair to represent edges. Changes in the adapter such as adding or removing vertices and edges are reflected in the underlying value graph.

    The class uses a converter from Guava's values to JGraphT's double weights. Thus, the resulting graph is weighted. Assume for example that the following class is the value type: 

     class MyValue
     implements
     Serializable
 {
     private double value;

     public MyValue(double value)
     {
         this.value = value;
     }

     public double getValue()
     {
         return value;
     }
 }
    Then one could create an adapter using the following code: 
     MutableValueGraph<String, MyValue> valueGraph =
     ValueGraphBuilder.directed().allowsSelfLoops(true).build();
 valueGraph.addNode("v1");
 valueGraph.addNode("v2");
 valueGraph.putEdgeValue("v1", "v2", new MyValue(5.0));
 
 Graph<String, EndpointPair<String>> graph = new MutableValueGraphAdapter<>(
     valueGraph, new MyValue(1.0), (ToDoubleFunction<MyValue> & Serializable) MyValue::getValue);
 
 double weight = graph.getEdgeWeight(EndpointPair.ordered("v1", "v2")); // should return 5.0

    This is a one-way conversion meaning that calling setEdgeWeight(EndpointPair, double) will throw an unsupported operation exception. Adjusting the weights can be done directly (by keeping an external reference) on the underlying MutableValueGraph and calling MutableValueGraph.putEdgeValue(Object, Object, Object). Changes on the values will be propagated upstream using the provided value converter.

    Author:
    Dimitrios Michail
    See Also:
    Serialized Form

    • Field Detail

      • defaultValue

        protected final W defaultValue

    • Constructor Detail

      • MutableValueGraphAdapter

        public MutableValueGraphAdapter​(com.google.common.graph.MutableValueGraph<V,​W> valueGraph,
                                W defaultValue,
                                java.util.function.ToDoubleFunction<W> valueConverter)
        Create a new adapter.
        Parameters:
        valueGraph - the value graph
        defaultValue - a default value to be used when creating new edges
        valueConverter - a function that converts a value to a double

      • MutableValueGraphAdapter

        public MutableValueGraphAdapter​(com.google.common.graph.MutableValueGraph<V,​W> valueGraph,
                                W defaultValue,
                                java.util.function.ToDoubleFunction<W> valueConverter,
                                java.util.function.Supplier<V> vertexSupplier,
                                java.util.function.Supplier<com.google.common.graph.EndpointPair<V>> edgeSupplier)
        Create a new adapter.
        Parameters:
        valueGraph - the value graph
        defaultValue - a default value to be used when creating new edges
        valueConverter - a function that converts a value to a double
        vertexSupplier - the vertex supplier
        edgeSupplier - the edge supplier

    • Method Detail

      • addEdge

        public com.google.common.graph.EndpointPair<V> addEdge​(V sourceVertex,
                                                       V targetVertex)
        Description copied from interface: Graph
        Creates a new edge in this graph, going from the source vertex to the target vertex, and returns the created edge. Some graphs do not allow edge-multiplicity. In such cases, if the graph already contains an edge from the specified source to the specified target, then this method does not change the graph and returns null.

        The source and target vertices must already be contained in this graph. If they are not found in graph IllegalArgumentException is thrown.

        This method creates the new edge e using this graph's edge supplier (see Graph.getEdgeSupplier()). For the new edge to be added e must not be equal to any other edge the graph (even if the graph allows edge-multiplicity). More formally, the graph must not contain any edge e2 such that e2.equals(e). If such e2 is found then the newly created edge e is abandoned, the method leaves this graph unchanged and returns null.

        If the underlying graph implementation's Graph.getEdgeSupplier() returns null, then this method cannot create edges and throws an UnsupportedOperationException.

        Specified by:
        addEdge in interface Graph<V,​W>
        Parameters:
        sourceVertex - source vertex of the edge.
        targetVertex - target vertex of the edge.
        Returns:
        The newly created edge if added to the graph, otherwise null.
        See Also:
        Graph.getEdgeSupplier()

      • addEdge

        public boolean addEdge​(V sourceVertex,
                       V targetVertex,
                       com.google.common.graph.EndpointPair<V> e)
        Adds the specified edge to this graph, going from the source vertex to the target vertex. More formally, adds the specified edge, e, to this graph if this graph contains no edge e2 such that e2.equals(e). If this graph already contains such an edge, the call leaves this graph unchanged and returns false. Some graphs do not allow edge-multiplicity. In such cases, if the graph already contains an edge from the specified source to the specified target, then this method does not change the graph and returns false. If the edge was added to the graph, returns true.

        The source and target vertices must already be contained in this graph. If they are not found in graph IllegalArgumentException is thrown.

        The provided edge object can either be null or must respect the source and target vertices that are provided as parameters.
        Specified by:
        addEdge in interface Graph<V,​W>
        Parameters:
        sourceVertex - source vertex of the edge.
        targetVertex - target vertex of the edge.
        e - edge to be added to this graph.
        Returns:
        true if this graph did not already contain the specified edge.
        Throws:
        java.lang.IllegalArgumentException - if edge e is not null and the sourceVertex parameter does not match the node U of the endpoint-pair
        java.lang.IllegalArgumentException - if edge e is not null and the targetVertex parameter does not match the node V of the endpoint-pair
        See Also:
        Graph.addEdge(Object, Object), Graph.getEdgeSupplier()

      • addVertex

        public V addVertex()
        Description copied from interface: Graph
        Creates a new vertex in this graph and returns it.

        This method creates the new vertex v using this graph's vertex supplier (see Graph.getVertexSupplier()). For the new vertex to be added v must not be equal to any other vertex in the graph. More formally, the graph must not contain any vertex v2 such that v2.equals(v). If such v2 is found then the newly created vertex v is abandoned, the method leaves this graph unchanged and throws an IllegalArgumentException.

        If the underlying graph implementation's Graph.getVertexSupplier() returns null, then this method cannot create vertices and throws an UnsupportedOperationException.

        Care must also be taken when interchanging calls to methods Graph.addVertex(Object) and Graph.addVertex(). In such a case the user must make sure never to add vertices in the graph using method Graph.addVertex(Object), which are going to be returned in the future by the supplied vertex supplier. Such a sequence will result into an IllegalArgumentException when calling method Graph.addVertex().

        Specified by:
        addVertex in interface Graph<V,​W>
        Returns:
        The newly created vertex if added to the graph.
        See Also:
        Graph.getVertexSupplier()

      • addVertex

        public boolean addVertex​(V v)
        Description copied from interface: Graph
        Adds the specified vertex to this graph if not already present. More formally, adds the specified vertex, v, to this graph if this graph contains no vertex u such that u.equals(v). If this graph already contains such vertex, the call leaves this graph unchanged and returns false. In combination with the restriction on constructors, this ensures that graphs never contain duplicate vertices.
        Specified by:
        addVertex in interface Graph<V,​W>
        Parameters:
        v - vertex to be added to this graph.
        Returns:
        true if this graph did not already contain the specified vertex.

      • removeEdge

        public com.google.common.graph.EndpointPair<V> removeEdge​(V sourceVertex,
                                                          V targetVertex)
        Description copied from interface: Graph
        Removes an edge going from source vertex to target vertex, if such vertices and such edge exist in this graph. Returns the edge if removed or null otherwise.
        Specified by:
        removeEdge in interface Graph<V,​W>
        Parameters:
        sourceVertex - source vertex of the edge.
        targetVertex - target vertex of the edge.
        Returns:
        The removed edge, or null if no edge removed.

      • removeEdge

        public boolean removeEdge​(com.google.common.graph.EndpointPair<V> e)
        Description copied from interface: Graph
        Removes the specified edge from the graph. Removes the specified edge from this graph if it is present. More formally, removes an edge e2 such that e2.equals(e), if the graph contains such edge. Returns true if the graph contained the specified edge. (The graph will not contain the specified edge once the call returns).

        If the specified edge is null returns false.

        Specified by:
        removeEdge in interface Graph<V,​W>
        Parameters:
        e - edge to be removed from this graph, if present.
        Returns:
        true if and only if the graph contained the specified edge.

      • removeVertex

        public boolean removeVertex​(V v)
        Description copied from interface: Graph
        Removes the specified vertex from this graph including all its touching edges if present. More formally, if the graph contains a vertex u such that u.equals(v), the call removes all edges that touch u and then removes u itself. If no such u is found, the call leaves the graph unchanged. Returns true if the graph contained the specified vertex. (The graph will not contain the specified vertex once the call returns).

        If the specified vertex is null returns false.

        Specified by:
        removeVertex in interface Graph<V,​W>
        Parameters:
        v - vertex to be removed from this graph, if present.
        Returns:
        true if the graph contained the specified vertex; false otherwise.

      • setEdgeWeight

        public void setEdgeWeight​(com.google.common.graph.EndpointPair<V> e,
                          double weight)
        Assigns a weight to an edge. This method always throws an UnsupportedOperationException since the adapter works one-way from values to weights. Adjusting the weights can be done by adjusting the values in the underlying ValueGraph which will automatically be propagated using the provided converter.
        Specified by:
        setEdgeWeight in interface Graph<V,​W>
        Parameters:
        e - edge on which to set weight
        weight - new weight for edge
        Throws:
        java.lang.UnsupportedOperationException - if the graph does not support weights

      • clone

        public java.lang.Object clone()
        Returns a shallow copy of this graph instance. Neither edges nor vertices are cloned.
        Overrides:
        clone in class java.lang.Object
        Returns:
        a shallow copy of this graph.
        Throws:
        java.lang.RuntimeException - in case the clone is not supported
        See Also:
        Object.clone()