Diva: a graph library for Java

[Marcus G. Daniels]

Those of you that have struggled to use the Swarm graph library or
tkobjc canvas features for representing, visualizing, or manipulating
graphs may be interested in `Diva' (Dynamic Interactive Visualization).

Diva is a large but modular Java package that can be used with the
Java layer of Swarm.  One of its components is a nice graph
visualization and editing package, with optional auto-layout features.
Diva even saves graphs as XML.

  http://www-cad.eecs.berkeley.edu/diva

Below is a fairly minimal graph display program.  (The demo programs
distributed with Diva are much neater.)

Note this requires Sun JDK 1.2; Kaffe doesn't have enough Swing
features implemented.

To run it, point the Java runtime at the Diva jar file.
In Bourne shell, like so:

$ CLASSPATH=.:$HOME/diva.jar:$CLASSPATH
$ export CLASSPATH
$ /usr/java1.2/bin/javac TestGraph.java # put the program below in this file
$ /usr/java1.2/bin/java TestGraph

import diva.canvas.*;
import diva.graph.*;
import diva.graph.layout.*;
import diva.graph.model.*;
import java.awt.*;
import javax.swing.*;
import java.awt.geom.*;
import diva.canvas.connector.ConnectorTarget;
import diva.canvas.connector.PerimeterSite;
import diva.canvas.connector.Connector;
import diva.canvas.connector.StraightConnector;
import diva.canvas.connector.ArcConnector;

public class TestGraph {
    public static void main(String argv[]) {
        new TestGraph ();
    }

    private GraphPane _gp1;

    
    private GraphModel _model;

    private TestGraph () {
        JFrame fr = new JFrame ("myFrame");
        _model = new GraphModel();
        JGraph gr1 = new JGraph(_model);
        _gp1 = (GraphPane)gr1.getCanvasPane();
        BasicGraphController gc1 =
          (BasicGraphController)_gp1.getGraphController();
        GraphView gv1 = _gp1.getGraphView();
        gv1.setIncrLayout(new RandomIncrLayout(gv1));
        fr.getContentPane().add("Center", gr1);
        
        BasicNodeRenderer bnr = new BasicNodeRenderer();
        bnr.setNodeShape(makePoly(5, 20));
        bnr.setNodeFill(Color.green);

        fr.setSize(600, 400);
        fr.setVisible(true);

        Node _a = _model.createNode("a");
        Node _b = _model.createNode("b");
        Node _c = _model.createNode("c");

        _model.addNode(_a);
        _model.addNode(_b);
        _model.addNode(_c);
        _model.createEdge("ab", _a, _b);
        _model.createEdge("ac", _a, _c);
    }

    private Shape makePoly(int num, double r) {
        GeneralPath p = new GeneralPath();
        p.moveTo((float)r,0);
        for(int i = 1; i < num; i++) {
            double theta = i*Math.PI*2.0/num;
            double x = r*Math.cos(theta);
            double y = r*Math.sin(theta);
            p.lineTo((float)x, (float)y);
        }
        p.closePath();
        return p;
    }
}

                  ==================================
   Swarm-Support is for discussion of the technical details of the day
   to day usage of Swarm.  For list administration needs (esp.
   [un]subscribing), please send a message to <address@hidden>
   with "help" in the body of the message.