[Jung-support] [Open Discussion] JPanel/JFrame used as vertexes never get foc

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The following forum message was posted by nedsana at http://sourceforge.net/projects/jung/forums/forum/252062/topic/6759828:

Hi,

for the last week I've been tying to implement the following task with JUNG
library:

[i]A graph should be created. Each vertex should be either JPanel(preferrably)
or JFrame. These vertexes will contain random GUI items(buttons, textfields,
dropdown menus, etc) and these should be fully functional.[/i]

So far I succeded in creating the graph with the JPanels and JFrames as vertexes,
but they are none functional. My investigation shows that the vertexes are out
of Focus. I tried to execute functions like setFocusable(true); requestfocus();
and added a focus listener, but it showed that the focus is always on the
Visualization Viewer instance.

So my questions:
1. How can I set the focus on the GUI vertexes?
2. If focus is not the solution to my problem, what should I do make the vertex
GUIs active?
3. A bit off-topic: currently my vertexes can be picked and moved only if they
are selected at the upper left corner of the JPanel/JFrame. How can I make the
whole area of the JPanel/JFrame pickable?

Here is my code:


[code]import java.awt.Color;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.awt.geom.Point2D;

import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;

import edu.uci.ics.jung.algorithms.layout.CircleLayout;
import edu.uci.ics.jung.algorithms.layout.Layout;
import edu.uci.ics.jung.graph.DirectedSparseGraph;
import edu.uci.ics.jung.visualization.RenderContext;
import edu.uci.ics.jung.visualization.VisualizationViewer;
import edu.uci.ics.jung.visualization.control.DefaultModalGraphMouse;
import edu.uci.ics.jung.visualization.control.ModalGraphMouse;
import edu.uci.ics.jung.visualization.picking.PickedState;
import edu.uci.ics.jung.visualization.renderers.Renderer;
import edu.uci.ics.jung.visualization.transform.shape.GraphicsDecorator;


class MyFocusListener implements FocusListener
{
	@Override
	public void focusGained(FocusEvent fe) {
		// TODO Auto-generated method stub
		Object obj = fe.getSource();
		System.out.println(obj.getClass() + " gained focus");
	}
	@Override
	public void focusLost(FocusEvent fe) {
		// TODO Auto-generated method stub
		Object obj = fe.getSource();
		System.out.println(obj.getClass() + " lost focus");
	}
};

public class GraphPanel extends Container
{
	static final long serialVersionUID = 420001L;
	DirectedSparseGraph<Number, Number> graph = null;
	VisualizationViewer<Number, Number> vv = null;
	PickedState<Number> pickedState = null;

	public GraphPanel(Number[][] nodes_list)
	{
		try
		{
			graph = new DirectedSparseGraph<Number, Number>();
			construct_graph(nodes_list);

			vv = new VisualizationViewer<Number, Number>
						(new CircleLayout<Number, Number>(graph), new Dimension(400, 400));
			vv.getRenderer().setVertexRenderer(new MyRenderer());

			vv.addFocusListener(new MyFocusListener());
			
			// The vertex pick listener
			pickedState = vv.getPickedVertexState();
			pickedState.addItemListener(new ItemListener()
			{
			    @Override
			    public void itemStateChanged(ItemEvent e)
			    {
			        Object subject = e.getItem();
			        if (subject instanceof Number)
			        {
			        	Number vertex = (Number) subject;
			            if (pickedState.isPicked(vertex))
			            {
			                System.out.println("Vertex " + vertex + " is now selected");
			            }
			            else
			            {
			                System.out.println("Vertex " + vertex + " no longer
selected");
			            }
			            
		                if(e.getStateChange() == ItemEvent.SELECTED) 
		                {
		                	System.out.println("Vertex " + vertex + " state is:"
+ e.getStateChange());
		                } 
		                else 
		                {
		                	System.out.println("Vertex " + vertex + " state is:"
+ e.getStateChange());
		                }
			            
			        }
			    }
			});

			// The following code adds capability for mouse picking of
			// vertices/edges. Vertices can even be moved!
			final DefaultModalGraphMouse<Number, Number> graphMouse =
new DefaultModalGraphMouse<Number, Number>();
			vv.setGraphMouse(graphMouse);
			graphMouse.setMode(ModalGraphMouse.Mode.PICKING);
		}
		catch (Exception e)
		{
			System.err.println("Failed to construct graph!\n");
			System.err.println("Caught Exception: " + e.getMessage());
		}
	}

	/*Attach the graph panel/container to a specified frame*/
	public void attach_to_frame(JFrame frame)
	{
		frame.setContentPane(vv);
	}

	private void construct_graph(Number[][] nodes_list)
	{