GT-3019 - Function Graph - Edge Routing - review fixes:

-fixed broken edge labels (labels were not offset correctly)
-fixed complex edge routing for edges going upward
-fixed bug that allowed toolbar multi-state actions to fire twice when
clicked

Ghidra/Features/FunctionGraph/src/main/java/ghidra/app/plugin/core/functiongraph/FGActionManager.java

@@ -855,7 +855,7 @@ class FGActionManager {
 		HelpLocation layoutHelpLocation =
 			new HelpLocation("FunctionGraphPlugin", "Function_Graph_Action_Layout");
 
-		layoutAction = new MultiStateDockingAction<>("Relayout Graph", plugin.getName()) {
+		layoutAction = new MultiStateDockingAction<>("Relayout Graph", plugin.getName(), true) {
 
 			@Override
 			protected void doActionPerformed(ActionContext context) {

Ghidra/Features/FunctionGraphDecompilerExtension/src/main/java/ghidra/app/plugin/core/functiongraph/graph/layout/DNLEdgeLabelRenderer.java

@@ -33,6 +33,7 @@ import edu.uci.ics.jung.visualization.transform.shape.GraphicsDecorator;
 import ghidra.app.plugin.core.functiongraph.graph.FGEdge;
 import ghidra.app.plugin.core.functiongraph.graph.vertex.FGVertex;
 import ghidra.graph.viewer.vertex.VisualGraphVertexShapeTransformer;
+import ghidra.program.model.symbol.FlowType;
 
 /**
  * An edge label renderer used with the {@link DecompilerNestedLayout}
@@ -86,11 +87,18 @@ class DNLEdgeLabelRenderer<V extends FGVertex, E extends FGEdge>
 		double cx = start.getX();
 		double cy = start.getY();
 
+		EdgeLabelRenderer labelRenderer = rc.getEdgeLabelRenderer();
+		Font font = rc.getEdgeFontTransformer().apply(e);
+		boolean isSelected = rc.getPickedEdgeState().isPicked(e);
+		Component component = labelRenderer.getEdgeLabelRendererComponent(rc.getScreenDevice(),
+			text, font, isSelected, e);
+		int labelWidth = component.getPreferredSize().width;
+
 		List<Point2D> articulationPoints = e.getArticulationPoints();
 		if (articulationPoints.isEmpty()) {
 			double vertexBottom = start.getY() + (vertexBounds.height >> 1); // location is centered
-			int textY = (int) (vertexBottom + edgeOffset); // below the vertex; above the bend 
+			double textY = (int) (vertexBottom + edgeOffset); // below the vertex; above the bend 
-			int textX = (int) (start.getX() + xDisplacement); // right of the edge
+			double textX = (int) (start.getX() + xDisplacement); // right of the edge
 			labelPointOffset.setLocation(textX, textY);
 		}
 		else if (articulationPoints.size() == 1) {
@@ -109,29 +117,26 @@ class DNLEdgeLabelRenderer<V extends FGVertex, E extends FGEdge>
 
 			double bx1 = bend1.getX();
 
+			FlowType flow = e.getFlowType();
+			boolean isRight = flow.isFallthrough() || flow.isUnConditional();
+
 			if (articulationPoints.size() == 2) {
 
-				int textX = (int) (vertexSide + edgeOffset); // right of the vertex 
+				double textX = (int) (vertexSide + edgeOffset); // right of the vertex 
-				int textY = (int) (cy + edgeOffset); // above the edge 
+				double textY = (int) (cy + edgeOffset); // above the edge 
 				labelPointOffset.setLocation(textX, textY);
 			}
-			else if (articulationPoints.size() == 3) {
+			else { // 3 or 4 articulations
+
+				double textY = (int) (vertexBottom + edgeOffset); // below the vertex; above the bend 
+				double textX = (int) (bx1 + xDisplacement); // right of the edge
+				if (!isRight) {
+					textX = bx1 - xDisplacement - labelWidth;
+				}
 
-				int textY = (int) (vertexBottom + edgeOffset); // below the vertex; above the bend 
-				int textX = (int) (bx1 + xDisplacement); // right of the edge
-				labelPointOffset.setLocation(textX, textY);
-			}
-			else { // if (articulationPoints.size() == 4) {
-				int textY = (int) (vertexBottom + edgeOffset); // below the vertex; above the bend 
-				int textX = (int) (bx1 + xDisplacement); // right of the edge
 				labelPointOffset.setLocation(textX, textY);
 			}
 		}
-		EdgeLabelRenderer labelRenderer = rc.getEdgeLabelRenderer();
-		Font font = rc.getEdgeFontTransformer().apply(e);
-		boolean isSelected = rc.getPickedEdgeState().isPicked(e);
-		Component component = labelRenderer.getEdgeLabelRendererComponent(rc.getScreenDevice(),
-			text, font, isSelected, e);
 
 		Dimension d = component.getPreferredSize();
 
@@ -142,7 +147,37 @@ class DNLEdgeLabelRenderer<V extends FGVertex, E extends FGEdge>
 
 		g.setTransform(xform);
 		g.draw(component, rc.getRendererPane(), 0, 0, d.width, d.height, true);
-
 		g.setTransform(old);
+
+		// debug
+		//labelArticulations(component, g, rc, e);
+	}
+
+	@SuppressWarnings("unused") // used during debug
+	private void labelArticulations(Component component, GraphicsDecorator g,
+			RenderContext<V, E> rc, E e) {
+
+		int offset = 5;
+		int counter = 1;
+		List<Point2D> points = e.getArticulationPoints();
+		for (Point2D p : points) {
+
+			MultiLayerTransformer multiLayerTransformer = rc.getMultiLayerTransformer();
+			p = multiLayerTransformer.transform(Layer.LAYOUT, p);
+
+			EdgeLabelRenderer labelRenderer = rc.getEdgeLabelRenderer();
+			Font font = rc.getEdgeFontTransformer().apply(e);
+			boolean isSelected = rc.getPickedEdgeState().isPicked(e);
+			component = labelRenderer.getEdgeLabelRendererComponent(rc.getScreenDevice(),
+				"p" + counter++, font, isSelected, e);
+
+			Dimension d = component.getPreferredSize();
+			AffineTransform old = g.getTransform();
+			AffineTransform xform = new AffineTransform(old);
+			xform.translate(p.getX() + offset, p.getY());
+			g.setTransform(xform);
+			g.draw(component, rc.getRendererPane(), 0, 0, d.width, d.height, true);
+			g.setTransform(old);
+		}
 	}
 }

Ghidra/Features/FunctionGraphDecompilerExtension/src/main/java/ghidra/app/plugin/core/functiongraph/graph/layout/DecompilerNestedLayout.java

@@ -56,11 +56,17 @@ import ghidra.util.task.TaskMonitor;
  * <p>Edges returning to the default code flow are painted lighter to de-emphasize them.  This
  * could be made into an option.
  * 
+ * <p>Edge routing herein defaults to 'simple routing'; 'complex routing' is a user option.  
+ * Simple routing will reduce edge noise as much as possible by combining/overlapping edges that
+ * flow towards the bottom of the function (returning code flow).  Also, edges may fall behind
+ * vertices for some functions.   Complex routing allows the user to visually follow the flow
+ * of an individual edge.  Complex routing will prevent edges from overlapping and will route
+ * edges around vertices.    Simple routing is better when the layout of the vertices is 
+ * important to the user; complex routing is better when edges/relationships are more 
+ * important to the user.
+ * 
  * TODO ideas:
  * -paint fallthrough differently for all, or just for those returning to the baseline
- * -using 'edge routing mode' that avoids vertices can be tweaked so that all returning edges also
- *  will not overlap (do this by keeping some sort of mapping for a given edge's column); when 
- *  not routing edges around vertices, the edges intentionally overlap, to reduce noise
  */
 public class DecompilerNestedLayout extends AbstractFGLayout {
 
@@ -265,9 +271,7 @@ public class DecompilerNestedLayout extends AbstractFGLayout {
 					Column loopEndColumn = layoutToGridMap.nextColumn(outermostCol);
 					List<Point2D> articulations = routeLoopEdge(start, end, loopEndColumn);
 					newEdgeArticulations.put(e, articulations);
-
+					continue;
-					vertex2dFactory.dispose();
-					return newEdgeArticulations;
 				}
 			}
 
@@ -340,7 +344,11 @@ public class DecompilerNestedLayout extends AbstractFGLayout {
 		// 
 
 		int delta = start.rowIndex - end.rowIndex;
-		int distanceSpacing = delta * EDGE_ENDPOINT_DISTANCE_MULTIPLIER;
+		int multiplier = EDGE_ENDPOINT_DISTANCE_MULTIPLIER;
+		if (useSimpleRouting()) {
+			multiplier = 1; // we allow edges to overlap with 'simple routing'
+		}
+		int distanceSpacing = delta * multiplier;
 
 		// Condensing Note: we have guilty knowledge that our parent class my condense the 
 		// vertices and edges towards the center of the graph after we calculate positions.
@@ -375,6 +383,9 @@ public class DecompilerNestedLayout extends AbstractFGLayout {
 		double y2 = y1;
 		articulations.add(new Point2D.Double(x2, y2));
 
+		Column column = vertex2dFactory.getColumn(x1);
+		routeAroundColumnVertices(start, end, column.index, vertex2dFactory, articulations, x2);
+
 		double x3 = x2;
 		double y3 = end.getBottom() - VERTEX_BORDER_THICKNESS;
 
@@ -386,9 +397,6 @@ public class DecompilerNestedLayout extends AbstractFGLayout {
 		y3 = Math.max(y3, endYLimit);
 		articulations.add(new Point2D.Double(x3, y3));
 
-		Column column = vertex2dFactory.getColumn(x1);
-		routeAroundColumnVertices(start, end, column.index, vertex2dFactory, articulations, x3);
-
 		double x4 = end.getX();
 		double y4 = y3;
 		articulations.add(new Point2D.Double(x4, y4)); // point is hidden behind the vertex
@@ -431,7 +439,11 @@ public class DecompilerNestedLayout extends AbstractFGLayout {
 		// 
 
 		int delta = end.rowIndex - start.rowIndex;
-		int distanceSpacing = delta * EDGE_ENDPOINT_DISTANCE_MULTIPLIER;
+		int multiplier = EDGE_ENDPOINT_DISTANCE_MULTIPLIER;
+		if (useSimpleRouting()) {
+			multiplier = 1; // we allow edges to overlap with 'simple routing'
+		}
+		int distanceSpacing = delta * multiplier;
 
 		double x1 = start.getX() - VERTEX_BORDER_THICKNESS; // start at the center
 
@@ -462,7 +474,7 @@ public class DecompilerNestedLayout extends AbstractFGLayout {
 
 		// restrict x from moving past the end vertex center x
 		int edgeOffset = 0;
-		if (getLayoutOptions().useEdgeRoutingAroundVertices()) {
+		if (usesEdgeArticulations()) {
 			// for now, only offset edge lines when we are performing complex routing
 			edgeOffset = EDGE_OFFSET_INCOMING_FROM_LEFT;
 		}
@@ -489,7 +501,11 @@ public class DecompilerNestedLayout extends AbstractFGLayout {
 		// 
 
 		int delta = end.rowIndex - start.rowIndex;
-		int distanceSpacing = delta * EDGE_ENDPOINT_DISTANCE_MULTIPLIER;
+		int multiplier = EDGE_ENDPOINT_DISTANCE_MULTIPLIER;
+		if (useSimpleRouting()) {
+			multiplier = 1; // we allow edges to overlap with 'simple routing'
+		}
+		int distanceSpacing = delta * multiplier;
 
 		double startRightX = start.getRight();
 		double x1 = startRightX - VERTEX_BORDER_THICKNESS; // start at the end
@@ -540,14 +556,15 @@ public class DecompilerNestedLayout extends AbstractFGLayout {
 	private void routeAroundColumnVertices(Vertex2d start, Vertex2d end, int column,
 			Vertex2dFactory vertex2dFactory, List<Point2D> articulations, double edgeX) {
 
-		if (!getLayoutOptions().useEdgeRoutingAroundVertices()) {
+		if (useSimpleRouting()) {
 			return;
 		}
 
+		boolean goingDown = true;
 		int startRow = start.rowIndex;
 		int endRow = end.rowIndex;
-
 		if (startRow > endRow) { // going upwards
+			goingDown = false;
 			endRow = start.rowIndex;
 			startRow = end.rowIndex;
 		}
@@ -578,15 +595,20 @@ public class DecompilerNestedLayout extends AbstractFGLayout {
 			}
 
 			double centerX = otherVertex.getX();
-			boolean isLeft = edgeX < centerX;
+			boolean goingLeft = edgeX < centerX;
 
-			// no need to check the 'y' value, as the end vertex is below this one
+			if (!goingDown) {
+				// for now, any time an edge goes up, we route it to the right
+				goingLeft = false;
+			}
 
-			if (isLeft) {
+			VertexClipper vertexClipper = new VertexClipper(goingLeft, goingDown);
-				if (edgeX >= otherVertex.getLeft()) {
-					// less than center; after the start of the vertex
 
-					/*
+			// no need to check the 'y' value, as the end vertex is above/below this one
+			if (vertexClipper.isClippingX(otherVertex, edgeX)) {
+
+				/*
+				 
 					 Must route around this vertex - new points:
 					 -p1 - just above the intersection point
 					 -p2 - just past the left edge
@@ -599,89 +621,60 @@ public class DecompilerNestedLayout extends AbstractFGLayout {
 					   | |     |
 					   | '-----'
 					   '---.
-					   	   |
+					   	   |					   	   
+				*/
+
+				// p1 - same x; y just above vertex
+				double x = edgeX;
+				double y = vertexClipper.getTopOffset(otherVertex, vertexToEdgeOffset);
+				articulations.add(new Point2D.Double(x, y));
+
+				// Maybe merge points if they are too close together.  Visually, many lines 
+				// moving around intersecting vertices looks busy.  When the intersecting 
+				// vertices are close together, we remove some of the articulations in order to
+				// smooth out the edges.
+				if (articulations.size() > 2) {
+
+					/*			 	
+						The last articulation is the one added before this method was called, which
+						lies just below the intersecting vertex.   The articulation before that is 
+						the one that is the one that is sending the x value straight into the 
+						intersecting vertex.  Delete that point as well so that the entire edge is
+						shifted to the outside of the intersecting vertex.  This will get repeated
+						for each vertex that is intersecting.		 			 	  			 	
 					*/
-
+					Point2D previousArticulation = articulations.get(articulations.size() - 2);
-					// p1 - same x; y just above vertex
+					int closenessHeight = 50;
-					double x = edgeX;
+					double previousY = previousArticulation.getY();
-					double y = otherVertex.getTop() - vertexToEdgeOffset;
+					if (vertexClipper.isTooCloseY(y, previousY, closenessHeight)) {
-					articulations.add(new Point2D.Double(x, y));
+						articulations.remove(articulations.size() - 1);
-
+						articulations.remove(articulations.size() - 1);
-					// maybe merge points if they are too close together
+						Point2D newPrevious = articulations.get(articulations.size() - 1);
-					if (articulations.size() > 2) {
+						y = newPrevious.getY();
-						Point2D previousArticulation = articulations.get(articulations.size() - 2);
-						int closenessHeight = 50;
-						double previousY = previousArticulation.getY();
-						if (y - previousY < closenessHeight) {
-							// remove our first articulation and the one before that so that
-							// the get merged into on line on the outside of the vertex
-							articulations.remove(articulations.size() - 1);
-							articulations.remove(articulations.size() - 1);
-							Point2D newPrevious = articulations.get(articulations.size() - 1);
-							y = newPrevious.getY();
-						}
 					}
-
-					// p2 - move over; same y
-					int offset = Math.max(vertexToEdgeOffset, distanceSpacing);
-					offset *= exaggerationFactor;
-					x = otherVertex.getLeft() - offset;
-					articulations.add(new Point2D.Double(x, y));
-
-					// p3 - same x; move y below the vertex
-					y = otherVertex.getBottom() + vertexToEdgeOffset;
-					articulations.add(new Point2D.Double(x, y));
-
-					// p4 - move over back to our original x; same y
-					x = edgeX;
-					articulations.add(new Point2D.Double(x, y));
 				}
-			}
-			else { // right
 
-				double otherEnd = otherVertex.getRight();
+				// p2 - move over; same y
-				if (edgeX < otherEnd) {
+				int offset = Math.max(vertexToEdgeOffset, distanceSpacing);
-					// greater than center; before the end of the vertex
+				offset *= exaggerationFactor;
-					// (see not above for routing info)
+				x = vertexClipper.getSideOffset(otherVertex, offset);
+				articulations.add(new Point2D.Double(x, y));
 
-					// p1 - same x; y just above vertex
+				// p3 - same x; move y above/below the vertex
-					double x = edgeX;
+				y = vertexClipper.getBottomOffset(otherVertex, vertexToEdgeOffset);
-					double y = otherVertex.getTop() - vertexToEdgeOffset;
+				articulations.add(new Point2D.Double(x, y));
-					articulations.add(new Point2D.Double(x, y));
 
-					// maybe merge points if they are too close together
+				// p4 - move over back to our original x; same y
-					if (articulations.size() > 2) {
+				x = edgeX;
-						Point2D previousArticulation = articulations.get(articulations.size() - 2);
+				articulations.add(new Point2D.Double(x, y));
-						int closenessHeight = 50;
-						double previousY = previousArticulation.getY();
-						if (y - previousY < closenessHeight) {
-							// remove our first articulation and the one before that so that
-							// the get merged into on line on the outside of the vertex
-							articulations.remove(articulations.size() - 1);
-							articulations.remove(articulations.size() - 1);
-							Point2D newPrevious = articulations.get(articulations.size() - 1);
-							y = newPrevious.getY();
-						}
-					}
-
-					// p2 - move over; same y
-					int offset = Math.max(vertexToEdgeOffset, distanceSpacing);
-					offset *= exaggerationFactor;
-					x = otherEnd + offset;
-					articulations.add(new Point2D.Double(x, y));
-
-					// p3 - same x; move y below the vertex
-					y = otherVertex.getBottom() + vertexToEdgeOffset;
-					articulations.add(new Point2D.Double(x, y));
-
-					// p4 - move over back to our original x; same y
-					x = edgeX;
-					articulations.add(new Point2D.Double(x, y));
-				}
 			}
 		}
 	}
 
+	private boolean useSimpleRouting() {
+		return !getLayoutOptions().useEdgeRoutingAroundVertices();
+	}
+
 	private List<Point2D> routeLoopEdge(Vertex2d start, Vertex2d end, Column loopEndColumn) {
 
 		// going backwards
@@ -691,8 +684,17 @@ public class DecompilerNestedLayout extends AbstractFGLayout {
 		int halfWidth = loopEndColumn.getPaddedWidth(isCondensedLayout()) >> 1;
 		double x = loopEndColumn.x + halfWidth; // middle of the column
 
-		Point2D startVertexPoint = start.center;
+		int startRow = start.rowIndex;
+		int endRow = end.rowIndex;
+		if (startRow > endRow) { // going upwards			
+			endRow = start.rowIndex;
+			startRow = end.rowIndex;
+		}
 
+		int delta = endRow - startRow;
+		x += delta; // adding the delta makes overlap less likely
+
+		Point2D startVertexPoint = start.center;
 		double y1 = startVertexPoint.getY();
 		Point2D first = new Point2D.Double(x, y1);
 		articulations.add(first);
@@ -745,7 +747,7 @@ public class DecompilerNestedLayout extends AbstractFGLayout {
 	}
 
 	private void debug(String text) {
-//		System.err.println(text);
+		// System.err.println(text);
 	}
 
 	private void printParts(int depth, BlockGraph block) {
@@ -937,6 +939,59 @@ public class DecompilerNestedLayout extends AbstractFGLayout {
 // Inner Classes
 //==================================================================================================	
 
+	/**
+	 * Encapsulates knowledge of edge direction (up/down, left/right) and uses that knowledge
+	 * to report vertex offsets from the appropriate side and top/bottom
+	 */
+	private class VertexClipper {
+
+		boolean goingLeft;
+		boolean goingDown;
+
+		VertexClipper(boolean isLeft, boolean isBottom) {
+			this.goingLeft = isLeft;
+			this.goingDown = isBottom;
+		}
+
+		private double getSide(Vertex2d v) {
+			return goingLeft ? v.getLeft() : v.getRight();
+		}
+
+		double getTopOffset(Vertex2d v, int offset) {
+			return goingDown ? v.getTop() - offset : v.getBottom() + offset;
+		}
+
+		double getBottomOffset(Vertex2d v, int offset) {
+			return goingDown ? v.getBottom() + offset : v.getTop() - offset;
+		}
+
+		double getSideOffset(Vertex2d v, int offset) {
+
+			double side = getSide(v);
+			if (goingLeft) {
+				return side - offset;
+			}
+			return side + offset;
+		}
+
+		boolean isTooCloseY(double topY, double bottomY, double threshold) {
+			double delta = goingDown ? topY - bottomY : bottomY - topY;
+			return delta < threshold;
+		}
+
+		boolean isClippingX(Vertex2d v, double x) {
+
+			double side = getSide(v);
+			if (goingLeft) {
+				return x >= side;
+			}
+			return x < side;
+		}
+	}
+
+	/**
+	 * Factory for creating and caching {@link Vertex2d} objects
+	 */
 	private class Vertex2dFactory {
 
 		private VisualGraphVertexShapeTransformer<FGVertex> vertexShaper;
@@ -1216,7 +1271,8 @@ public class DecompilerNestedLayout extends AbstractFGLayout {
 
 		@Override
 		public String toString() {
-			return PcodeBlock.typeToName(pcodeBlock.getType()) + " - " + pcodeBlock.getStart();
+			return PcodeBlock.typeToName(pcodeBlock.getType()) + " - " + getName() + " - " +
+				pcodeBlock.getStart();
 		}
 	}
 

Ghidra/Framework/Docking/src/main/java/docking/menu/MultiStateDockingAction.java

@@ -35,6 +35,11 @@ import resources.icons.EmptyIcon;
  * drop-down icon that allows users to change the state of the button.  Also, by default, as
  * the user presses the button, it will execute the action corresponding to the current 
  * state.
+ * 
+ * <p>Warning: if you use this action in a toolbar, then be sure to call the 
+ * {@link #MultiStateDockingAction(String, String, boolean) correct constructor}.  If you call
+ * another constructor, or pass false for this boolean above, your 
+ * {@link #doActionPerformed(ActionContext)} method will get called twice.
  *
  * @param <T> the type of the user data
  * @see MultiActionDockingAction
@@ -56,10 +61,25 @@ public abstract class MultiStateDockingAction<T> extends DockingAction {
 		// stub for toolbar actions
 	};
 
+	/**
+	 * Call this constructor with this action will not be added to a toolbar
+	 * 
+	 * @param name the action name
+	 * @param owner the owner
+	 * @see #MultiStateDockingAction(String, String, boolean)
+	 */
 	public MultiStateDockingAction(String name, String owner) {
 		this(name, owner, false);
 	}
 
+	/**
+	 * Use this constructor explicitly when this action is used in a toolbar, passing true 
+	 * for <code>isToolbarAction</code> (see the javadoc header note).
+	 * 
+	 * @param name the action name
+	 * @param owner the owner
+	 * @param isToolbarAction true if this action is a toolbar action
+	 */
 	protected MultiStateDockingAction(String name, String owner, boolean isToolbarAction) {
 		super(name, owner);
 		multiActionGenerator = context -> getStateActions();
@@ -87,6 +107,9 @@ public abstract class MultiStateDockingAction<T> extends DockingAction {
 	 * <p>
 	 * Also, if the parameter is true, then the button will behave like a button in terms of
 	 * mouse feedback.  If false, then the button will behave more like a label.
+	 * 
+	 * @param doPerformAction true to call {@link #doActionPerformed(ActionContext)} when the
+	 *        user presses the button for this action (not the drop-down menu; see above)
 	 */
 	public void setPerformActionOnPrimaryButtonClick(boolean doPerformAction) {
 		performActionOnPrimaryButtonClick = doPerformAction;
@@ -116,6 +139,8 @@ public abstract class MultiStateDockingAction<T> extends DockingAction {
 	 * This is the callback to be overridden when the child wishes to respond to user button
 	 * presses that are on the button and not the drop-down.  This will only be called if
 	 * {@link #performActionOnPrimaryButtonClick} is true.
+	 * 
+	 * @param context the action context 
 	 */
 	protected void doActionPerformed(ActionContext context) {
 		// override me to do work

Ghidra/Framework/Graph/src/main/java/ghidra/graph/viewer/renderer/VisualGraphRenderer.java

@@ -34,6 +34,9 @@ import ghidra.graph.viewer.layout.*;
  * This was created to add the ability to paint selected vertices above other vertices.  We need
  * this since the Jung Graph has no notion of Z-order and thus does not let us specify that any
  * particular vertex should be above another one.
+ * 
+ * @param <V> the vertex type
+ * @param <E> the edge type 
  */
 public class VisualGraphRenderer<V extends VisualVertex, E extends VisualEdge<V>>
 		extends edu.uci.ics.jung.visualization.renderers.BasicRenderer<V, E> {