Add support for drawing graph vertices with fixed position

src/main/java/ee/ut/dendroloj/Dendrologist.java

@@ -173,7 +173,7 @@ public static void drawGraph(int[][] adjacencyMatrix, String[] labels) {
      * <b>EXPERIMENTAL API</b>
      * <p>
      * Draws a graph based on the provided adjacency matrix.
-     * Infinite values and NaN in the adjacency matrix are treated as missing edges.
+     * Infinite and NaN values in the adjacency matrix are treated as missing edges.
      *
      * @param adjacencyMatrix graph adjacency matrix; value at [i][j] is treated as the weight of the edge from vertex i to vertex j
      * @param labels          string labels for vertices; pass null to use vertex indices as labels
@@ -199,7 +199,7 @@ public static void drawGraph(double[][] adjacencyMatrix, String[] labels) {
      * <b>EXPERIMENTAL API</b>
      * <p>
      * Draws a graph based on the provided adjacency matrix.
-     * Infinite values and NaN in the adjacency matrix are treated as missing edges.
+     * Infinite and NaN values in the adjacency matrix are treated as missing edges.
      *
      * @param adjacencyMatrix graph adjacency matrix; value at [i][j] is treated as the weight of the edge from vertex i to vertex j
      * @param labels          string labels for vertices; pass null to use vertex indices as labels

src/main/java/ee/ut/dendroloj/GenericGraphLayout.java

@@ -18,6 +18,11 @@ public static Graph assembleGraph(GraphCanvas<?> graphCanvas) {
         for (var vertex : graphCanvas.vertices) {
             Node node = graph.addNode(IdHelper.getNodeId(vertex.vertex));
             node.setAttribute("label", vertex.label);
+            if (vertex.fixed) {
+                node.setAttribute("layout._fixed");
+                node.setAttribute("layout.frozen");
+                node.setAttribute("xy", vertex.x, vertex.y);
+            }
             if (vertex.color != null) node.setAttribute("ui.color", vertex.color);
         }
         for (var edge : graphCanvas.edges) {

src/main/java/ee/ut/dendroloj/GraphCanvas.java

@@ -2,7 +2,9 @@
 
 import java.awt.*;
 import java.util.ArrayList;
+import java.util.HashSet;
 import java.util.List;
+import java.util.Set;
 
 /**
  * <b>EXPERIMENTAL API</b>
@@ -14,21 +16,52 @@
  */
 public final class GraphCanvas<V> {
 
+    private final Set<String> drawnVertices = new HashSet<>();
     final List<Vertex<V>> vertices = new ArrayList<>();
     final List<Edge<V>> edges = new ArrayList<>();
 
-    public void drawVertex(V vertex) {
-        if (vertex == null) throw new NullPointerException("Vertex must not be null");
-        drawVertex(vertex, vertex.toString(), null);
-    }
+    // TODO: Add overload that allows drawing a vertex with the vertex itself as a default label.
+    // Note that this will make the order of parameters for drawFixedVertex a little awkward.
+    // Also note that the default label being the vertex itself converted to a string
+    // might be non-obvious for reference types (especially ones that don't override toString).
+
+    // public void drawVertex(V vertex) {
+    //    if (vertex == null) throw new NullPointerException("Vertex must not be null");
+    //    drawVertex(vertex, vertex.toString(), null);
+    // }
 
     public void drawVertex(V vertex, String label) {
-        drawVertex(vertex, label, null);
+        if (vertex == null) throw new NullPointerException("Vertex must not be null");
+        addVertex(new Vertex<>(vertex, label, null));
     }
 
     public void drawVertex(V vertex, String label, Color color) {
         if (vertex == null) throw new NullPointerException("Vertex must not be null");
-        vertices.add(new Vertex<>(vertex, label, color));
+        addVertex(new Vertex<>(vertex, label, color));
+    }
+
+    // public void drawFixedVertex(V vertex, double x, double y) {
+    //    if (vertex == null) throw new NullPointerException("Vertex must not be null");
+    //    drawVertex(vertex, vertex.toString(), null);
+    // }
+
+    public void drawFixedVertex(V vertex, String label, double x, double y) {
+        if (vertex == null) throw new NullPointerException("Vertex must not be null");
+        addVertex(new Vertex<>(vertex, label, null, x, y));
+    }
+
+    public void drawFixedVertex(V vertex, String label, double x, double y, Color color) {
+        if (vertex == null) throw new NullPointerException("Vertex must not be null");
+        addVertex(new Vertex<>(vertex, label, color, x, y));
+    }
+
+    private void addVertex(Vertex<V> vertex) {
+        String id = IdHelper.getNodeId(vertex.vertex);
+        if (drawnVertices.contains(id)) {
+            throw new IllegalArgumentException("Vertex " + vertex.vertex + " (" + vertex.label + ") has already been drawn");
+        }
+        drawnVertices.add(id);
+        vertices.add(vertex);
     }
 
     /**
@@ -79,11 +112,26 @@ static final class Vertex<T> {
         public final T vertex;
         public final String label;
         public final Color color;
+        public final boolean fixed;
+        public final double x;
+        public final double y;
 
         private Vertex(T vertex, String label, Color color) {
             this.vertex = vertex;
             this.label = label;
             this.color = color;
+            this.fixed = false;
+            this.x = 0.0;
+            this.y = 0.0;
+        }
+
+        private Vertex(T vertex, String label, Color color, double x, double y) {
+            this.vertex = vertex;
+            this.label = label;
+            this.color = color;
+            this.fixed = true;
+            this.x = x;
+            this.y = y;
         }
     }
 

src/main/java/ee/ut/dendroloj/GraphGUI.java

@@ -3,6 +3,7 @@
 import org.graphstream.graph.Graph;
 import org.graphstream.ui.geom.Point2;
 import org.graphstream.ui.geom.Point3;
+import org.graphstream.ui.graphicGraph.GraphicElement;
 import org.graphstream.ui.graphicGraph.GraphicGraph;
 import org.graphstream.ui.layout.Layout;
 import org.graphstream.ui.swing_viewer.SwingViewer;
@@ -128,6 +129,16 @@ public void mouseDragged(MouseEvent event) {
                     }
                 }
             }
+
+            @Override
+            protected void mouseButtonReleaseOffElement(GraphicElement element, MouseEvent event) {
+                if (!element.hasAttribute("layout._fixed")) {
+                    view.freezeElement(element, false);
+                }
+                if (event.getButton() != 3) {
+                    element.removeAttribute("ui.clicked");
+                }
+            }
         };
         view.setMouseManager(restrictedDefaultMouseManager);
 

src/test/java/GraafKatsed.java

@@ -26,11 +26,11 @@ public static void main(String[] args) {
         // Dendrologist.drawGraph(M, null);
 
         List<Tipp> tipud = new ArrayList<>();
-        tipud.add(new Tipp("A"));
-        tipud.add(new Tipp("B"));
-        tipud.add(new Tipp("C"));
-        tipud.add(new Tipp("D"));
-        tipud.add(new Tipp("E"));
+        tipud.add(new Tipp("A", 1, 0));
+        tipud.add(new Tipp("B", 2, 5));
+        tipud.add(new Tipp("C", 0, 1));
+        tipud.add(new Tipp("D", 1, 1));
+        tipud.add(new Tipp("E", 0, 0));
 
         tipud.get(0).kaared.add(new Kaar(11, tipud.get(1)));
         tipud.get(0).kaared.add(new Kaar(22, tipud.get(2)));
@@ -40,20 +40,24 @@ public static void main(String[] args) {
 
         GraphCanvas<Tipp> lõuend = new GraphCanvas<>();
         for (Tipp tipp : tipud) {
-            lõuend.drawVertex(tipp, tipp.tähis, Color.GREEN);
+            lõuend.drawFixedVertex(tipp, tipp.tähis, tipp.x, tipp.y);
             for (Kaar kaar : tipp.kaared) {
-                lõuend.drawEdge(tipp, kaar.lõppTipp, String.valueOf(kaar.kaal), Color.MAGENTA);
+                lõuend.drawEdge(tipp, kaar.lõppTipp, String.valueOf(kaar.kaal));
             }
         }
         Dendrologist.drawGraph(lõuend);
     }
 
     private static class Tipp {
         public final String tähis;
+        public final double x;
+        public final double y;
         public final List<Kaar> kaared;
 
-        public Tipp(String tähis) {
+        public Tipp(String tähis, double x, double y) {
             this.tähis = tähis;
+            this.x = x;
+            this.y = y;
             this.kaared = new ArrayList<>();
         }
     }