Merge pull request jgrapht#288 from d-michail/ext-providers-interface…

…-refactoring

Unified name providers for exporters using a common interface

jgrapht-demo/src/main/java/org/jgrapht/demo/GraphMLExportDemo.java

@@ -165,14 +165,14 @@ public GraphVertex createVertex()
 
         // create GraphML exporter
         GraphMLExporter<GraphVertex, DefaultWeightedEdge> exporter =
-            new GraphMLExporter<>(new VertexNameProvider<GraphVertex>()
+            new GraphMLExporter<>(new ComponentNameProvider<GraphVertex>()
             {
                 @Override
-                public String getVertexName(GraphVertex v)
+                public String getName(GraphVertex v)
                 {
                     return v.id;
                 }
-            }, null, new IntegerEdgeNameProvider<>(), null);
+            }, null, new IntegerComponentNameProvider<>(), null);
 
         // set to export the internal edge weights
         exporter.setExportEdgeWeights(true);

jgrapht-ext/src/main/java/org/jgrapht/ext/CSVExporter.java

@@ -55,7 +55,7 @@ public class CSVExporter<V, E>
 {
     private static final char DEFAULT_DELIMITER = ',';
 
-    private final VertexNameProvider<V> vertexIDProvider;
+    private final ComponentNameProvider<V> vertexIDProvider;
     private final Set<CSVFormat.Parameter> parameters;
     private CSVFormat format;
     private char delimiter;
@@ -66,7 +66,7 @@ public class CSVExporter<V, E>
      */
     public CSVExporter()
     {
-        this(new IntegerNameProvider<>(), CSVFormat.ADJACENCY_LIST, DEFAULT_DELIMITER);
+        this(new IntegerComponentNameProvider<>(), CSVFormat.ADJACENCY_LIST, DEFAULT_DELIMITER);
     }
 
     /**
@@ -76,7 +76,7 @@ public CSVExporter()
      */
     public CSVExporter(CSVFormat format)
     {
-        this(new IntegerNameProvider<>(), format, DEFAULT_DELIMITER);
+        this(new IntegerComponentNameProvider<>(), format, DEFAULT_DELIMITER);
     }
 
     /**
@@ -87,7 +87,7 @@ public CSVExporter(CSVFormat format)
      */
     public CSVExporter(CSVFormat format, char delimiter)
     {
-        this(new IntegerNameProvider<>(), format, delimiter);
+        this(new IntegerComponentNameProvider<>(), format, delimiter);
     }
 
     /**
@@ -97,7 +97,7 @@ public CSVExporter(CSVFormat format, char delimiter)
      * @param format the format to use
      * @param delimiter delimiter to use
      */
-    public CSVExporter(VertexNameProvider<V> vertexIDProvider, CSVFormat format, char delimiter)
+    public CSVExporter(ComponentNameProvider<V> vertexIDProvider, CSVFormat format, char delimiter)
     {
         if (vertexIDProvider == null) {
             throw new IllegalArgumentException("Vertex id provider cannot be null");
@@ -207,9 +207,9 @@ public void setDelimiter(char delimiter)
     private void exportAsEdgeList(Graph<V, E> g, PrintWriter out)
     {
         for (E e : g.edgeSet()) {
-            exportEscapedField(out, vertexIDProvider.getVertexName(g.getEdgeSource(e)));
+            exportEscapedField(out, vertexIDProvider.getName(g.getEdgeSource(e)));
             out.print(delimiter);
-            exportEscapedField(out, vertexIDProvider.getVertexName(g.getEdgeTarget(e)));
+            exportEscapedField(out, vertexIDProvider.getName(g.getEdgeTarget(e)));
             out.println();
         }
     }
@@ -218,21 +218,21 @@ private void exportAsAdjacencyList(Graph<V, E> g, PrintWriter out)
     {
         if (g instanceof DirectedGraph<?, ?>) {
             for (V v : g.vertexSet()) {
-                exportEscapedField(out, vertexIDProvider.getVertexName(v));
+                exportEscapedField(out, vertexIDProvider.getName(v));
                 for (E e : ((DirectedGraph<V, E>) g).outgoingEdgesOf(v)) {
                     V w = Graphs.getOppositeVertex(g, e, v);
                     out.print(delimiter);
-                    exportEscapedField(out, vertexIDProvider.getVertexName(w));
+                    exportEscapedField(out, vertexIDProvider.getName(w));
                 }
                 out.println();
             }
         } else {
             for (V v : g.vertexSet()) {
-                exportEscapedField(out, vertexIDProvider.getVertexName(v));
+                exportEscapedField(out, vertexIDProvider.getName(v));
                 for (E e : g.edgesOf(v)) {
                     V w = Graphs.getOppositeVertex(g, e, v);
                     out.print(delimiter);
-                    exportEscapedField(out, vertexIDProvider.getVertexName(w));
+                    exportEscapedField(out, vertexIDProvider.getName(w));
                 }
                 out.println();
             }
@@ -250,14 +250,14 @@ private void exportAsMatrix(Graph<V, E> g, PrintWriter out)
         if (exportNodeId) {
             for (V v : g.vertexSet()) {
                 out.print(delimiter);
-                exportEscapedField(out, vertexIDProvider.getVertexName(v));
+                exportEscapedField(out, vertexIDProvider.getName(v));
             }
             out.println();
         }
         int n = g.vertexSet().size();
         for (V v : g.vertexSet()) {
             if (exportNodeId) {
-                exportEscapedField(out, vertexIDProvider.getVertexName(v));
+                exportEscapedField(out, vertexIDProvider.getName(v));
                 out.print(delimiter);
             }
             int i = 0;

jgrapht-ext/src/main/java/org/jgrapht/ext/ComponentNameProvider.java

@@ -0,0 +1,39 @@
+/*
+ * (C) Copyright 2016-2016, by Dimitrios Michail and Contributors.
+ *
+ * JGraphT : a free Java graph-theory library
+ *
+ * This program and the accompanying materials are dual-licensed under
+ * either
+ *
+ * (a) the terms of the GNU Lesser General Public License version 2.1
+ * as published by the Free Software Foundation, or (at your option) any
+ * later version.
+ *
+ * or (per the licensee's choosing)
+ *
+ * (b) the terms of the Eclipse Public License v1.0 as published by
+ * the Eclipse Foundation.
+ */
+package org.jgrapht.ext;
+
+/**
+ * Provides a name for a component.
+ *
+ * @param <T> the type of the component
+ */
+public interface ComponentNameProvider<T>
+{
+
+    /**
+     * Returns a unique name. This is useful when exporting a graph, as it ensures that all
+     * vertices/edges are assigned simple, consistent names.
+     *
+     * @param component the component to be named
+     * @return the name of the component
+     */
+    String getName(T component);
+
+}
+
+// End ComponentNameProvider.java

jgrapht-ext/src/main/java/org/jgrapht/ext/ComponentUpdater.java

@@ -0,0 +1,39 @@
+/*
+ * (C) Copyright 2015-2016, by Wil Selwood and Contributors.
+ *
+ * JGraphT : a free Java graph-theory library
+ *
+ * This program and the accompanying materials are dual-licensed under
+ * either
+ *
+ * (a) the terms of the GNU Lesser General Public License version 2.1
+ * as published by the Free Software Foundation, or (at your option) any
+ * later version.
+ *
+ * or (per the licensee's choosing)
+ *
+ * (b) the terms of the Eclipse Public License v1.0 as published by
+ * the Eclipse Foundation.
+ */
+package org.jgrapht.ext;
+
+import java.util.*;
+
+/**
+ * Type to handle updates to a component when an import gets more information about it after it has
+ * been created.
+ *
+ * @param <T> the component type
+ */
+public interface ComponentUpdater<T>
+{
+    /**
+     * Update component with the extra attributes.
+     *
+     * @param component to update
+     * @param attributes to add to the component
+     */
+    void update(T component, Map<String, String> attributes);
+}
+
+// End ComponentUpdater.java

jgrapht-ext/src/main/java/org/jgrapht/ext/DOTExporter.java

@@ -38,9 +38,15 @@
 public class DOTExporter<V, E>
     implements GraphExporter<V, E>
 {
-    private VertexNameProvider<V> vertexIDProvider;
-    private VertexNameProvider<V> vertexLabelProvider;
-    private EdgeNameProvider<E> edgeLabelProvider;
+    /**
+     * Default graph id used by the exporter.
+     */
+    public static final String DEFAULT_GRAPH_ID = "G";
+
+    private ComponentNameProvider<Graph<V, E>> graphIDProvider;
+    private ComponentNameProvider<V> vertexIDProvider;
+    private ComponentNameProvider<V> vertexLabelProvider;
+    private ComponentNameProvider<E> edgeLabelProvider;
     private ComponentAttributeProvider<V> vertexAttributeProvider;
     private ComponentAttributeProvider<E> edgeAttributeProvider;
 
@@ -50,7 +56,7 @@ public class DOTExporter<V, E>
      */
     public DOTExporter()
     {
-        this(new IntegerNameProvider<>(), null, null);
+        this(new IntegerComponentNameProvider<>(), null, null, null, null, null);
     }
 
     /**
@@ -63,10 +69,10 @@ public DOTExporter()
      *        to the file.
      */
     public DOTExporter(
-        VertexNameProvider<V> vertexIDProvider, VertexNameProvider<V> vertexLabelProvider,
-        EdgeNameProvider<E> edgeLabelProvider)
+        ComponentNameProvider<V> vertexIDProvider, ComponentNameProvider<V> vertexLabelProvider,
+        ComponentNameProvider<E> edgeLabelProvider)
     {
-        this(vertexIDProvider, vertexLabelProvider, edgeLabelProvider, null, null);
+        this(vertexIDProvider, vertexLabelProvider, edgeLabelProvider, null, null, null);
     }
 
     /**
@@ -86,16 +92,48 @@ public DOTExporter(
      *        not be written to the file.
      */
     public DOTExporter(
-        VertexNameProvider<V> vertexIDProvider, VertexNameProvider<V> vertexLabelProvider,
-        EdgeNameProvider<E> edgeLabelProvider,
+        ComponentNameProvider<V> vertexIDProvider, ComponentNameProvider<V> vertexLabelProvider,
+        ComponentNameProvider<E> edgeLabelProvider,
         ComponentAttributeProvider<V> vertexAttributeProvider,
         ComponentAttributeProvider<E> edgeAttributeProvider)
+    {
+        this(
+            vertexIDProvider, vertexLabelProvider, edgeLabelProvider, vertexAttributeProvider,
+            edgeAttributeProvider, null);
+    }
+
+    /**
+     * Constructs a new DOTExporter object with the given ID, label, attribute, and graph id
+     * providers. Note that if a label provider conflicts with a label-supplying attribute provider,
+     * the label provider is given precedence.
+     *
+     * @param vertexIDProvider for generating vertex IDs. Must not be null.
+     * @param vertexLabelProvider for generating vertex labels. If null, vertex labels will not be
+     *        written to the file (unless an attribute provider is supplied which also supplies
+     *        labels).
+     * @param edgeLabelProvider for generating edge labels. If null, edge labels will not be written
+     *        to the file.
+     * @param vertexAttributeProvider for generating vertex attributes. If null, vertex attributes
+     *        will not be written to the file.
+     * @param edgeAttributeProvider for generating edge attributes. If null, edge attributes will
+     *        not be written to the file.
+     * @param graphIDProvider for generating the graph ID. If null the graph is named
+     *        {@link #DEFAULT_GRAPH_ID}.
+     */
+    public DOTExporter(
+        ComponentNameProvider<V> vertexIDProvider, ComponentNameProvider<V> vertexLabelProvider,
+        ComponentNameProvider<E> edgeLabelProvider,
+        ComponentAttributeProvider<V> vertexAttributeProvider,
+        ComponentAttributeProvider<E> edgeAttributeProvider,
+        ComponentNameProvider<Graph<V, E>> graphIDProvider)
     {
         this.vertexIDProvider = vertexIDProvider;
         this.vertexLabelProvider = vertexLabelProvider;
         this.edgeLabelProvider = edgeLabelProvider;
         this.vertexAttributeProvider = vertexAttributeProvider;
         this.edgeAttributeProvider = edgeAttributeProvider;
+        this.graphIDProvider =
+            (graphIDProvider == null) ? any -> DEFAULT_GRAPH_ID : graphIDProvider;
     }
 
     /**
@@ -111,11 +149,16 @@ public void exportGraph(Graph<V, E> g, Writer writer)
         String indent = "  ";
         String connector;
 
+        String graphId = graphIDProvider.getName(g);
+        if (graphId == null || graphId.trim().isEmpty()) {
+            graphId = DEFAULT_GRAPH_ID;
+        }
+
         if (g instanceof DirectedGraph<?, ?>) {
-            out.println("digraph G {");
+            out.println("digraph " + graphId + " {");
             connector = " -> ";
         } else {
-            out.println("graph G {");
+            out.println("graph " + graphId + " {");
             connector = " -- ";
         }
 
@@ -124,7 +167,7 @@ public void exportGraph(Graph<V, E> g, Writer writer)
 
             String labelName = null;
             if (vertexLabelProvider != null) {
-                labelName = vertexLabelProvider.getVertexName(v);
+                labelName = vertexLabelProvider.getName(v);
             }
             Map<String, String> attributes = null;
             if (vertexAttributeProvider != null) {
@@ -143,7 +186,7 @@ public void exportGraph(Graph<V, E> g, Writer writer)
 
             String labelName = null;
             if (edgeLabelProvider != null) {
-                labelName = edgeLabelProvider.getEdgeName(e);
+                labelName = edgeLabelProvider.getName(e);
             }
             Map<String, String> attributes = null;
             if (edgeAttributeProvider != null) {
@@ -206,7 +249,7 @@ private String getVertexID(V v)
         // (b) compile regex patterns
 
         // use the associated id provider for an ID of the given vertex
-        String idCandidate = vertexIDProvider.getVertexName(v);
+        String idCandidate = vertexIDProvider.getName(v);
 
         // now test that this is a valid ID
         boolean isAlphaDig = idCandidate.matches("[a-zA-Z]+([\\w_]*)?");
@@ -222,6 +265,7 @@ private String getVertexID(V v)
             "Generated id '" + idCandidate + "'for vertex '" + v
                 + "' is not valid with respect to the .dot language");
     }
+
 }
 
 // End DOTExporter.java

jgrapht-ext/src/main/java/org/jgrapht/ext/DOTImporter.java

@@ -102,7 +102,7 @@ public class DOTImporter<V, E>
     private static final int DONE = 32;
 
     private VertexProvider<V> vertexProvider;
-    private VertexUpdater<V> vertexUpdater;
+    private ComponentUpdater<V> vertexUpdater;
     private EdgeProvider<V, E> edgeProvider;
 
     /**
@@ -123,13 +123,13 @@ public DOTImporter(VertexProvider<V> vertexProvider, EdgeProvider<V, E> edgeProv
      *
      * @param vertexProvider Provider to create a vertex
      * @param edgeProvider Provider to create an edge
-     * @param updater Method used to update an existing Vertex
+     * @param vertexUpdater Method used to update an existing Vertex
      */
     public DOTImporter(
-        VertexProvider<V> vertexProvider, EdgeProvider<V, E> edgeProvider, VertexUpdater<V> updater)
+        VertexProvider<V> vertexProvider, EdgeProvider<V, E> edgeProvider, ComponentUpdater<V> vertexUpdater)
     {
         this.vertexProvider = vertexProvider;
-        this.vertexUpdater = updater;
+        this.vertexUpdater = vertexUpdater;
         this.edgeProvider = edgeProvider;
     }
 
@@ -537,7 +537,7 @@ private void processCompleteNode(String node, Graph<V, E> graph, Map<String, V>
             vertexes.put(id, vertex);
         } else {
             if (vertexUpdater != null) {
-                vertexUpdater.updateVertex(existing, attributes);
+                vertexUpdater.update(existing, attributes);
             } else {
                 throw new ImportException(
                     "Update required for vertex " + id + " but no vertexUpdater provided");