Enhancement for #11. Added "edge.arrowsize" property and SmartGraphEdge.getStylableArrow();

Author: brunomnsilva

smartgraph.properties

@@ -16,9 +16,12 @@ vertex.label = true
 #
 edge.tooltip = true
 edge.label = false
-# only makes sense if displaying an oriented graph 
+# only makes sense if displaying a directed graph 
 edge.arrow = true
 
+# size in pixels (side of a triangle); only for directed graphs
+edge.arrowsize = 5
+
 # (automatic) Force-directed layout related configurations
 #   -- You should experiment with different values for your 
 #   -- particular problem, knowing that not all will achieve 

src/com/brunomnsilva/smartgraph/Main.java

@@ -112,8 +112,9 @@ public void start(Stage ignored) {
         graphView.setEdgeDoubleClickAction(graphEdge -> {
             System.out.println("Edge contains element: " + graphEdge.getUnderlyingEdge().element());
             //dynamically change the style when clicked
-            graphEdge.setStyle("-fx-stroke: black; -fx-stroke-width: 2;");
+            graphEdge.setStyle("-fx-stroke: black; -fx-stroke-width: 3;");
 
+            graphEdge.getStylableArrow().setStyle("-fx-stroke: black; -fx-stroke-width: 3;");
 
             //uncomment to see edges being removed after click
             //Edge<String, String> underlyingEdge = graphEdge.getUnderlyingEdge();

src/com/brunomnsilva/smartgraph/graphview/SmartArrow.java

@@ -37,13 +37,18 @@ public class SmartArrow extends Path implements SmartStylableNode {
     /* Styling proxy */
     private final SmartStyleProxy styleProxy;
 
-    public SmartArrow() {
+    /**
+     * Constructor
+     * 
+     * @param size determines the size of the arrow (side of the triangle in pixels)
+     */
+    public SmartArrow(double size) {
 
         /* Create this arrow shape */
         getElements().add(new MoveTo(0, 0));  
-        getElements().add(new LineTo(-5, 5));
+        getElements().add(new LineTo(-size, size));
         getElements().add(new MoveTo(0, 0));        
-        getElements().add(new LineTo(-5, -5));    
+        getElements().add(new LineTo(-size, -size));    
 
         /* Add the corresponding css class */
         styleProxy = new SmartStyleProxy(this);

src/com/brunomnsilva/smartgraph/graphview/SmartGraphEdge.java

@@ -50,4 +50,13 @@ public interface SmartGraphEdge<E, V> extends SmartStylableNode {
      * @see SmartGraphPanel
      */
     public Edge<E, V> getUnderlyingEdge();
+    
+    /**
+     * Returns the attached arrow of the edge, for styling purposes.
+     * 
+     * The arrows are only used with directed graphs.
+     * 
+     * @return arrow reference; null if does not exist.
+     */
+    public SmartStylableNode getStylableArrow();
 }

src/com/brunomnsilva/smartgraph/graphview/SmartGraphEdgeCurve.java

@@ -218,4 +218,9 @@ public void attachArrow(SmartArrow arrow) {
     public SmartArrow getAttachedArrow() {
         return this.attachedArrow;
     }
+    
+    @Override
+    public SmartStylableNode getStylableArrow() {
+        return this.attachedArrow;
+    }
 }

src/com/brunomnsilva/smartgraph/graphview/SmartGraphEdgeLine.java

@@ -102,6 +102,8 @@ public SmartLabel getAttachedLabel() {
     public Edge<E, V> getUnderlyingEdge() {
         return underlyingEdge;
     }
+    
+    
 
     @Override
     public void attachArrow(SmartArrow arrow) {
@@ -132,5 +134,10 @@ public void attachArrow(SmartArrow arrow) {
     public SmartArrow getAttachedArrow() {
         return this.attachedArrow;
     }
+
+    @Override
+    public SmartStylableNode getStylableArrow() {
+        return this.attachedArrow;
+    }
 
 }

src/com/brunomnsilva/smartgraph/graphview/SmartGraphPanel.java

@@ -434,7 +434,7 @@ private void initNodes() {
                 addEdge(graphEdge, edge);
 
                 if (this.edgesWithArrows) {
-                    SmartArrow arrow = new SmartArrow();
+                    SmartArrow arrow = new SmartArrow(this.graphProperties.getEdgeArrowSize());
                     graphEdge.attachArrow(arrow);
                     this.getChildren().add(arrow);
                 }
@@ -605,7 +605,7 @@ The opposite vertex exists in the (di)graph, but we have not yet
                 SmartGraphEdgeBase graphEdge = createEdge(edge, graphVertexIn, graphVertexOut);
 
                 if (this.edgesWithArrows) {
-                    SmartArrow arrow = new SmartArrow();
+                    SmartArrow arrow = new SmartArrow(this.graphProperties.getEdgeArrowSize());
                     graphEdge.attachArrow(arrow);
                     this.getChildren().add(arrow);
                 }
@@ -1001,6 +1001,7 @@ public SmartStylableNode getStylableEdge(E edgeElement) {
         }
         return null;
     }
+        
 
     /**
      * Loads the stylesheet and applies the .graph class to this panel.

src/com/brunomnsilva/smartgraph/graphview/SmartGraphProperties.java

@@ -62,6 +62,9 @@ public class SmartGraphProperties {
 
     private static final boolean DEFAULT_EDGE_USE_ARROW = true;
     private static final String PROPERTY_EDGE_USE_ARROW = "edge.arrow";
+    
+    private static final int DEFAULT_ARROW_SIZE = 5;
+    private static final String PROPERTY_ARROW_SIZE = "edge.arrowsize";
 
     private static final double DEFAULT_REPULSION_FORCE = 1000;
     private static final String PROPERTY_REPULSION_FORCE = "layout.repulsive-force";
@@ -201,6 +204,15 @@ public boolean getUseEdgeArrow() {
         return getBooleanProperty(PROPERTY_EDGE_USE_ARROW, DEFAULT_EDGE_USE_ARROW);
     }
 
+    /**
+     * Returns a property that indicates the size of the {@link SmartArrow}.
+     * 
+     * @return corresponding property value
+     */
+    public double getEdgeArrowSize() {
+        return getDoubleProperty(PROPERTY_ARROW_SIZE, DEFAULT_ARROW_SIZE);
+    }
+    
 
     private double getDoubleProperty(String propertyName, double defaultValue) {
         String p = properties.getProperty(propertyName, Double.toString(defaultValue));