java - The prefuse edge arrow didn't show up. Even i set up the code for the edge arrow

Question

In order to make the edge with the arrow, I set up some line of codes in the GraphView.java example. However, the arrow didn't show up. Is there any way to show the arrow? The following lines are what I did for the edge with arrow.

    EdgeRenderer er = new EdgeRenderer(Constants.EDGE_TYPE_LINE, Constants.EDGE_ARROW_FORWARD);
    drf.setDefaultEdgeRenderer(er);
    m_vis.setRendererFactory(drf);

    draw.add(new ColorAction(edges, VisualItem.FILLCOLOR, ColorLib.gray(200)));
    draw.add(new ColorAction(edges, VisualItem.STROKECOLOR, ColorLib.gray(200)));

The below source code is the whole example code.

public class GraphView extends JPanel {

private static final String graph = "graph";
private static final String nodes = "graph.nodes";
private static final String edges = "graph.edges";

private Visualization m_vis;

public GraphView(Graph g, String label) {
    super(new BorderLayout());
    
    // create a new, empty visualization for our data
    m_vis = new Visualization();
    
    // --------------------------------------------------------------------
    // set up the renderers
    
    LabelRenderer tr = new LabelRenderer();
    tr.setRoundedCorner(8, 8);
    DefaultRendererFactory drf = new DefaultRendererFactory(tr);
   // set up the edge with arrow
    EdgeRenderer er = new EdgeRenderer(Constants.EDGE_TYPE_LINE, Constants.EDGE_ARROW_FORWARD);
    drf.setDefaultEdgeRenderer(er);
    m_vis.setRendererFactory(drf);

    // --------------------------------------------------------------------
    // register the data with a visualization
    
    // adds graph to visualization and sets renderer label field
    setGraph(g, label);
    
    // fix selected focus nodes
    TupleSet focusGroup = m_vis.getGroup(Visualization.FOCUS_ITEMS); 
    focusGroup.addTupleSetListener(new TupleSetListener() {
        public void tupleSetChanged(TupleSet ts, Tuple[] add, Tuple[] rem)
        {
            for ( int i=0; i<rem.length; ++i )
                ((VisualItem)rem[i]).setFixed(false);
            for ( int i=0; i<add.length; ++i ) {
                ((VisualItem)add[i]).setFixed(false);
                ((VisualItem)add[i]).setFixed(true);
            }
            if ( ts.getTupleCount() == 0 ) {
                ts.addTuple(rem[0]);
                ((VisualItem)rem[0]).setFixed(false);
            }
            m_vis.run("draw");
        }
    });
    
    
    
    // --------------------------------------------------------------------
    // create actions to process the visual data

    int hops = 30;
    final GraphDistanceFilter filter = new GraphDistanceFilter(graph, hops);

    ColorAction fill = new ColorAction(nodes, 
            VisualItem.FILLCOLOR, ColorLib.rgb(200,200,255));
    fill.add(VisualItem.FIXED, ColorLib.rgb(255,100,100));
    fill.add(VisualItem.HIGHLIGHT, ColorLib.rgb(255,200,125));
    
    // add colors for edge and arrow.
    ActionList draw = new ActionList();
    draw.add(filter);
    draw.add(fill);
    draw.add(new ColorAction(nodes, VisualItem.STROKECOLOR, 0));
    draw.add(new ColorAction(nodes, VisualItem.TEXTCOLOR, ColorLib.rgb(0,0,0)));
    draw.add(new ColorAction(edges, VisualItem.FILLCOLOR, ColorLib.gray(200)));
    draw.add(new ColorAction(edges, VisualItem.STROKECOLOR, ColorLib.gray(200)));
    
    ActionList animate = new ActionList(Activity.INFINITY);
    animate.add(new ForceDirectedLayout(graph));
    animate.add(fill);
    animate.add(new RepaintAction());
    
    // finally, we register our ActionList with the Visualization.
    // we can later execute our Actions by invoking a method on our
    // Visualization, using the name we've chosen below.
    m_vis.putAction("draw", draw);
    m_vis.putAction("layout", animate);

    m_vis.runAfter("draw", "layout");
    
    
    // --------------------------------------------------------------------
    // set up a display to show the visualization
    
    Display display = new Display(m_vis);
    display.setSize(700,700);
    display.pan(350, 350);
    display.setForeground(Color.GRAY);
    display.setBackground(Color.WHITE);
    
    // main display controls
    display.addControlListener(new FocusControl(1));
    display.addControlListener(new DragControl());
    display.addControlListener(new PanControl());
    display.addControlListener(new ZoomControl());
    display.addControlListener(new WheelZoomControl());
    display.addControlListener(new ZoomToFitControl());
    display.addControlListener(new NeighborHighlightControl());
    
    display.setForeground(Color.GRAY);
    display.setBackground(Color.WHITE);
    
    // --------------------------------------------------------------------        
    // launch the visualization
    
    // create a panel for editing force values
    ForceSimulator fsim = ((ForceDirectedLayout)animate.get(0)).getForceSimulator();
    JForcePanel fpanel = new JForcePanel(fsim);       
    
    final JValueSlider slider = new JValueSlider("Distance", 0, hops, hops);
    slider.addChangeListener(new ChangeListener() {
        public void stateChanged(ChangeEvent e) {
            filter.setDistance(slider.getValue().intValue());
            m_vis.run("draw");
        }
    });
    slider.setBackground(Color.WHITE);
    slider.setPreferredSize(new Dimension(300,30));
    slider.setMaximumSize(new Dimension(300,30));
    
    Box cf = new Box(BoxLayout.Y_AXIS);
    cf.add(slider);
    cf.setBorder(BorderFactory.createTitledBorder("Connectivity Filter"));
    fpanel.add(cf);

    //fpanel.add(opanel);
    
    fpanel.add(Box.createVerticalGlue());
    
    // create a new JSplitPane to present the interface
    JSplitPane split = new JSplitPane();
    split.setLeftComponent(display);
    split.setRightComponent(fpanel);
    split.setOneTouchExpandable(true);
    split.setContinuousLayout(false);
    split.setDividerLocation(700);
    
    // now we run our action list
    m_vis.run("draw");
    
    add(split);
}

public void setGraph(Graph g, String label) {
    // update labeling
    DefaultRendererFactory drf = (DefaultRendererFactory)
                                            m_vis.getRendererFactory();
    ((LabelRenderer)drf.getDefaultRenderer()).setTextField(label);
    
    // update graph
    m_vis.removeGroup(graph);
    VisualGraph vg = m_vis.addGraph(graph, g);
    m_vis.setValue(edges, null, VisualItem.INTERACTIVE, Boolean.FALSE);
    VisualItem f = (VisualItem)vg.getNode(0);
    m_vis.getGroup(Visualization.FOCUS_ITEMS).setTuple(f);
    f.setFixed(false);
}

// ------------------------------------------------------------------------
// Main and demo methods

public static void main(String[] args) {
    UILib.setPlatformLookAndFeel();
    
    // create graphview
    String datafile = null;
    String label = "label";
    if ( args.length > 1 ) {
        datafile = args[0];
        label = args[1];
    }
    
    JFrame frame = demo(datafile, label);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}

public static JFrame demo() {
    return demo((String)null, "label");
}

public static JFrame demo(String datafile, String label) {
    Graph g = null;
    if ( datafile == null ) {
        g = GraphLib.getGrid(15,15);
        label = "label";
    } else {
        try {
            g = new GraphMLReader().readGraph(datafile);
        } catch ( Exception e ) {
            e.printStackTrace();
            System.exit(1);
        }
    }
    return demo(g, label);
}

public static JFrame demo(Graph g, String label) {
    final GraphView view = new GraphView(g, label);
    
    // set up menu
    JMenu dataMenu = new JMenu("Data");
    dataMenu.add(new OpenGraphAction(view));
    dataMenu.add(new GraphMenuAction("Grid","ctrl 1",view) {
        protected Graph getGraph() {
            return GraphLib.getGrid(15,15);
        }
    });
    dataMenu.add(new GraphMenuAction("Clique","ctrl 2",view) {
        protected Graph getGraph() {
            return GraphLib.getClique(10);
        }
    });
    dataMenu.add(new GraphMenuAction("Honeycomb","ctrl 3",view) {
        protected Graph getGraph() {
            return GraphLib.getHoneycomb(5);
        }
    });
    dataMenu.add(new GraphMenuAction("Balanced Tree","ctrl 4",view) {
        protected Graph getGraph() {
            return GraphLib.getBalancedTree(3,5);
        }
    });
    dataMenu.add(new GraphMenuAction("Diamond Tree","ctrl 5",view) {
        protected Graph getGraph() {
            return GraphLib.getDiamondTree(3,3,3);
        }
    });
    JMenuBar menubar = new JMenuBar();
    menubar.add(dataMenu);
    
    // launch window
    JFrame frame = new JFrame("p r e f u s e  |  g r a p h v i e w");
    frame.setJMenuBar(menubar);
    frame.setContentPane(view);
    frame.pack();
    frame.setVisible(true);
    
    frame.addWindowListener(new WindowAdapter() {
        public void windowActivated(WindowEvent e) {
            view.m_vis.run("layout");
        }
        public void windowDeactivated(WindowEvent e) {
            view.m_vis.cancel("layout");
        }
    });
    
    return frame;
}


// ------------------------------------------------------------------------

/**
 * Swing menu action that loads a graph into the graph viewer.
 */
public abstract static class GraphMenuAction extends AbstractAction {
    private GraphView m_view;
    public GraphMenuAction(String name, String accel, GraphView view) {
        m_view = view;
        this.putValue(AbstractAction.NAME, name);
        this.putValue(AbstractAction.ACCELERATOR_KEY,
                      KeyStroke.getKeyStroke(accel));
    }
    public void actionPerformed(ActionEvent e) {
        m_view.setGraph(getGraph(), "label");
    }
    protected abstract Graph getGraph();
}

public static class OpenGraphAction extends AbstractAction {
    private GraphView m_view;

    public OpenGraphAction(GraphView view) {
        m_view = view;
        this.putValue(AbstractAction.NAME, "Open File...");
        this.putValue(AbstractAction.ACCELERATOR_KEY,
                      KeyStroke.getKeyStroke("ctrl O"));
    }
    public void actionPerformed(ActionEvent e) {
        Graph g = IOLib.getGraphFile(m_view);
        if ( g == null ) return;
        String label = getLabel(m_view, g);
        if ( label != null ) {
            m_view.setGraph(g, label);
        }
    }
    public static String getLabel(Component c, Graph g) {
        // get the column names
        Table t = g.getNodeTable();
        int  cc = t.getColumnCount();
        String[] names = new String[cc];
        for ( int i=0; i<cc; ++i )
            names[i] = t.getColumnName(i);
        
        // where to store the result
        final String[] label = new String[1];

        // -- build the dialog -----
        // we need to get the enclosing frame first
        while ( c != null && !(c instanceof JFrame) ) {
            c = c.getParent();
        }
        final JDialog dialog = new JDialog(
                (JFrame)c, "Choose Label Field", true);
        
        // create the ok/cancel buttons
        final JButton ok = new JButton("OK");
        ok.setEnabled(false);
        ok.addActionListener(new ActionListener() {
           public void actionPerformed(ActionEvent e) {
               dialog.setVis

Answer 1

等待大神答复