Open Jgraph Problem

Hi,

I have go through the example given in http://sourceforge.net/projects/openjgraph/ for Open Jgraph by Jesus M. Salvo Jr. I have amended one of the sample (SampleTreeLayout.java) codes as below:

package examples;
import salvo.jesus.graph.;
import salvo.jesus.graph.visual.;
import salvo.jesus.graph.visual.layout.;
import salvo.jesus.graph.visual.drawing.;
import java.awt.;
import java.awt.event.;
import javax.swing.;
import java.awt.geom.;
/
@author Jesus M. Salvo Jr.
/

public class SampleTreeLayout extends JFrame {
VisualGraph vgraph;

public SampleTreeLayout() {}

private Tree initTree() throws Exception {
Tree tree = new TreeImpl();
Vertex v1, v2, v3, v4 ;

v1 = new VertexImpl( "1" );
v2 = new VertexImpl( "2" );
v3 = new VertexImpl( "3" );
v4 = new VertexImpl( "4" );


tree.addNode( null, v1 );
tree.addNode( v1, v2 );
tree.addNode( v2, v3 );
tree.addNode( v3, v4 );

return tree;
}

private void showTree( Tree tree ) {
GraphEditor editor;
GraphLayoutManager layoutManager;

// Get a VisualGraph
editor = new GraphEditor();
editor.setGraph( tree );
vgraph = editor.getVisualGraph();

// Initialise a Tree layout manager
layoutManager = new LayeredTreeLayout( editor.getVisualGraph() );
editor.setGraphLayoutManager( layoutManager );

// Make it all visible
this.getContentPane().setLayout( new GridLayout(1,2));
this.getContentPane().add( editor );

Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
Dimension frameSize = new Dimension( screenSize.width - 50, screenSize.height - 50 );

this.setSize( frameSize );
this.setLocation((int)(screenSize.getWidth() - frameSize.getWidth()) / 2, (int)(screenSize.getHeight() - frameSize.getHeight()) / 2);

// Terminate the application when the window closes
this.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) { System.exit(0); }
});
}

public static void main( String args[] ) throws Exception {
SampleTreeLayout app = new SampleTreeLayout();

Tree tree = app.initTree();
app.showTree( tree );
app.setTitle( "SampleNodeFlow" );
app.setVisible( true );
app.vgraph.layout();
}
}
//end of code.

My problems are:

1. How to make the graph output to be displayed automatically in horizontal format?. Currently, the graph output is displayed in vertical format.
2. How to make the node to be displayed in circle shape? Currently, the node is displayed in rectangle shape.
3. How can I program so that node number 1 is in red color and node number 4 is in green color?
4. How to make each node available to be right click and an option given to the user to select ?add new node?? Once the user select ?add new node? the new node will appear. Following the above example, if user right click at node 2 and select ?add new node?, the new node (node 5) should appear. How can I do that?

I hope that I am not burdening all of you with these questions. I really appreciate if anyone of you can help me on this. I am a newbie in Java language.

Thank you.

Ulamraja.